UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

	WASHINGTON, D.C.  20460

OFFICE OF

PREVENTION, PESTICIDES AND

TOXIC SUBSTANCES

PC Code:  029001

DP#:  318737

March 9, 2007

Memorandum

Subject:	Environmental Risk Assessment for Proposed Section 3 New Use
Registration of 1,3-Dichloropropene in Drip Irrigation In Grapes

To:	Mary Waller, RM21

Fungicide Branch

Registration Division

From:	Shannon Borges, Biologist

William P. Eckel, Ph.D., Agronomist

Environmental Risk Branch 2

Environmental Fate and Effects Division

Through:   	Thomas Bailey, Ph.D., Branch Chief

Environmental Risk Branch 2

Environmental Fate and Effects Division

EFED has completed an ecological risk assessment for the proposed new
use registration of 1,3-Dichloropropene (1,3-D; Telone) for control of
nematodes and grape phylloxera via drip irrigation in grapes.  1,3-D is
a nematicide and insecticide that is generally applied through
fumigation, although it has been registered for use in drip irrigation
in melons.  It is also registered as a herbicide.  1,3-D breaks down
into 3-chloroallyl alcohol and 3-chloroacrylic acid, which are also
toxic to some taxa.  This review also includes an assessment of the
risks of these degradates.

Pertinent risk assessments previously completed for this chemical
include an EFED RED Chapter (herbicide and nematicide/insecticide
fumigant uses) completed in 1997 and an ecological risk assessment for a
Section 18 Registration for use of Telone in drip irrigation in Grapes
in California completed in 1999.  These have provided some information
used in this risk assessment.  Since the dates of these assessments, new
ecological effects data and new PRZM-EXAMS modeling scenarios have
become available.  Because of the proposed method of application (drip),
incidental soil ingestion of pesticides is directly evaluated in this
assessment.  The proposed label allows for the drip application of 1,3-D
above, at, or below the ground surface, but only risk resulting from
buried drip lines was addressed in the Section 18 risk assessment.  Drip
irrigation was not addressed in EFED’s RED Chapter.  The depth of drip
application of 1,3-D application significantly impacts risk conclusions.
 Based on the application instructions proposed on the label, updated
ecological effects data, and new modeling scenarios, EFED’s risk
conclusions for the proposed new use are summarized below.

Risks associated with 1,3-D:

Acute and chronic risk of 1,3-D to listed and non-listed mammals due to
incidental soil ingestion is minimal.  Based on the work of Beyer et al.
(2004), estimates of 1,3-D in soil following an application via drip
irrigation to grapes, and random foraging within a grape crop, RQ
estimates based on daily incidental soil ingestion rates were below the
acute and chronic LOCs for mammals.

Acute risk of 1,3-D to listed and non-listed birds (and reptiles) due to
incidental soil ingestion is minimal.  Chronic risk cannot be determined
due to lack of data, but since exposure is likely to be very low,
chronic risk is not expected to be a concern for birds as a result of
the proposed use.

Acute and chronic risk of 1,3-D to mammals as a result of inhalation is
expected to be minimal.  EFED does not have LOCs with which to compare
RQs calculated with mammalian inhalation LC50s and NOAECs; however, RQs
are low values (acute RQ <0.01, chronic RQ = 0.002 - 0.22) and likely
indicate minimal risk due to inhalation.

Risk of 1,3-D exposure to non-target listed and non-listed
dicotyledonous plants inhabiting semi-aquatic areas is likely due to
runoff from treated areas.  RQs exceed the LOCs for these listed and
non-listed species if 1,3-D is applied in drip lines that are not
buried.  Based on exposure modeling, applications made through drip
lines buried at least 5 cm minimize risk to plants in nearby terrestrial
and semi-aquatic areas.

Acute risk to listed and non-listed freshwater fish and acute and
chronic risk of 1,3-D to listed and non-listed freshwater invertebrates
is likely if 1,3-D is applied in drip lines at or above ground level.
Applications in which 1,3-D is applied in drip lines buried at 5 cm and
25 cm below the ground surface result in RQs that do not exceed acute or
chronic LOCs invertebrates or acute LOCs to fish.  Chronic risk to
freshwater fish cannot be determined because the chronic study with this
taxon was determined to be invalid. However, since 1,3-D is moderately
toxic to freshwater fish on an acute basis, EFED expects chronic risk to
be a concern.  Submission of a valid early life stage test with
freshwater fish will clarify this presumption.  EFED expects
applications made through buried drip lines would provide at least some
protection against chronic effects in freshwater fish if chronic risks
were to be identified.

Acute risk to listed and non-listed marine/estuarine fish, and acute and
chronic risk to listed and non-listed marine/estuarine invertebrates is
likely if 1,3-D is applied in drip lines at or above ground level.
Applications in which 1,3-D is applied in drip lines buried at 5 cm and
25 cm below the ground surface result in RQs that do not exceed acute
LOCs for marine/estuarine fish or acute and chronic LOCs for
marine/estuarine invertebrates.  NOAECs for determining chronic risk to
marine/estuarine invertebrates were estimated by calculating the ratio
of acute to chronic toxicity for freshwater invertebrates.  A similar
analysis could not be conducted for marine/estuarine fish because a
chronic toxicity value for freshwater fish is not available.  However,
since 1,3-D is highly toxic to marine/estuarine fish on an acute basis,
EFED expects chronic risk to be a concern.  EFED also expects protection
against chronic effects in this taxon if applications are made through
buried drip lines.

Risk to listed and non-listed aquatic vascular and non-vascular plants
as a result of exposure to 1,3-D from runoff is minimal.  This was found
for all application depths modeled.

Risks associated with 3-chloroallyl alcohol and 3-chloroacrylic acid
(degradates of 1,3-D):

Minimal acute risk is predicted for listed and non-listed mammals as a
result of exposure via soil ingestion to 3-chloroallyl alcohol and
3-chloroacrylic acid.  Chronic data are not available with which to
assess chronic risk to mammals, nor are acute and chronic data for
birds, so these risks remain uncertain.  Inhalation risks are not a
concern for the degradates, since they are not highly volatile.

The status of studies on terrestrial plants with 3-chloroallyl alcohol
and 3-chloroacrylic acid have not been determined, since questions were
raised as to how the effects of 1,3-D tests conducted simultaneously
were controlled within the test greenhouse.  These questions are being
investigated, and EFED will provide the status of these studies and
resulting risk conclusions as soon as they are known.

Minimal acute risk is predicted for listed and non-listed freshwater
fish, freshwater invertebrates, and aquatic-phase amphibians as a result
of exposure to 3-chloroallyl alcohol and 3-chloroacrylic acid in runoff.
 This was found at all application depths modeled.  Chronic data are not
available for these taxa, so chronic risk remains an uncertainty.

Acute toxicity data for marine/estuarine fish and invertebrates exposed
to 3-chloroallyl alcohol and 3-chloroacrylic acid are not available;
however, since their toxicity appears to be similar to that of
freshwater organisms with respect to 1,3-D, and because exposure to the
degradates is expected to be low, a similar conclusion of low risk is
expected for these taxa.  Chronic data for fish and invertebrates with
the degradates are not available, so this remains an uncertainty.

At- or above-ground applications of 1,3-D will result in EECs of
3-chloroallyl alcohol and 3-chloroacrylic acid in runoff that are high
enough to pose risk to listed freshwater aquatic plants.  Non-listed
aquatic plants did not have RQs that exceeded the LOC.

Aquatic EECs resulting from runoff were modeled for applications of
1,3-D and resulting concentrations of 3-chloroallyl alcohol and
3-chloroacrylic acid occurring at the ground surface and below ground at
5 cm and 25 cm depth.  EECs in nearby water bodies due to runoff
resulting from applications at 5 cm and 25 cm were not found to pose
acute or chronic risks to aquatic plants and animals or to plants
inhabiting semi-aquatic areas adjacent to vineyards in which 1,3-D is
applied.  Therefore, label requirements that restrict applications to
drip lines buried at least 5 cm will provide protection to listed and
non-listed aquatic plants and animals and listed and non-listed plants
in semi-aquatic areas.

Remaining data gaps for 1,3-D and its degradates are listed below.
These data gaps result in uncertainty in quantitatively evaluating the
ecological risks related to the proposed new use.

(§71-1) Avian oral LD50 tests with 3-chloroallyl alcohol and
3-chloroacrylic acid

(§122-1 and §123-1) Tier I and II seed emergence and vegetative vigor
tests with 3-chloroallyl alcohol, and 3-chloroacrylic acid (or
information clarifying methods in study already submitted that lead to
upgraded status)

(§72-4) Fish early life stage test with 1,3-D on freshwater fish

(§72-4) Fish early life stage and invertebrate life cycle tests with
1,3-D on marine/estuarine fish and invertebrates

	Ecological Risk Assessment:

Proposed Section 3 New Use Registration of 1,3-Dichloropropene (Telone)
For Use in Drip Irrigation in Grapes

	March 9, 2007

Prepared by:

Shannon Borges, Biologist

William P. Eckel, Ph.D, Agronomist

Environmental Risk Branch 2

Environmental Fate and Effects Division

Approved by:

Thomas Bailey, Ph.D, Branch Chief

Environmental Risk Branch 2

Environmental Fate and Effects Division

Table of Contents

I. Executive
Summary.................................................................
.................................................	1

II. Problem
Formulation.............................................................
..................................................	3

	A. Stressor Source and
Distribution............................................................
...........................	3

		1. Source and
Intensity...............................................................
.....................................	3

		2. Physical/Chemical/Fate and Transport
Properties.......................................................	4

		3. Pesticide Type, Class, and Mode of
Action.................................................................
6

		2. Overview of Pesticide
Usage...................................................................
....................	6

	B. Ecological Receptors and Measurement
Endpoints..........................................................	6

	C. Conceptual
Model...................................................................
..........................................	8

		1. Risk
Hypotheses..............................................................
............................................	8

		2.
Diagram.................................................................
.....................................................11

	D. Analysis
Plan....................................................................
..............................................	13

		1. Measures to Evaluate
Risk....................................................................
.....................	13

		2. Measures of
Effect..................................................................
...................................	14

		3. Data
Gaps....................................................................
...............................................	14

III.
Analysis................................................................
................................................................	14

	A. Environmental Fate
Analysis................................................................
..........................	14

	B. Measures of Terrestrial
Exposure................................................................
...................	15

	C. Measures of Aquatic
Exposure................................................................
.......................	17

	D. Ecological Effects
Characterization........................................................
........................	18

		1. Ecological Effects of
1,3-D...................................................................
.....................	18

		2. Ecological Effects of 3-Chloroallyl Alcohol and 3-Choloracrylic
Acid....................22

IV. Risk
Characterization........................................................
...................................................	23

	A. Risk
Estimation..............................................................
.................................................	23

	B. Risk
Description.............................................................
.................................................	32

V. Federally-Listed Species
Concerns................................................................
.......................	37

	A. Action
Area....................................................................
.................................................	37

	B. Taxonomic Groups Potentially at
Risk....................................................................
......	38

	C. Probit
Dose-Response...........................................................
..........................................	38

	D. Indirect Effects
Analysis................................................................
.................................	39

	E. Critical
Habitat.................................................................
...............................................	40

	F. Co-occurrence
Analysis................................................................
...................................	41

VI. Assumptions and
Uncertainties...........................................................
................................	41

Appendix I. Environmental Fate
Results.................................................................
..................	43

Appendix II. Effects Data for 1,3-Dichloropropene and its
Degradates....................................	57

Appendix III. Listed Species Co-occurring in States with Grape
Crops...................................	70

I.	Executive Summary

This document presents EFED’s ecological risk assessment for
1,3-dichloropropene (1,3-D) and its degradates, 3-chloroallyl alcohol
and 3-chloroacrylic acid.  1,3-D is being proposed for registration to
control nematodes and grape phylloxera through drip irrigation
applications in grapes.  It is proposed for use at a maximum application
rate of 17.68 lbs ai/acre, with a maximum concentration of 200 ppm in
irrigation water.  The proposed label allows one application at least 60
days pre-harvest and a second application within three weeks
post-harvest.  1,3-D is known to be toxic to several taxa, and its
degradates 3-chloroallyl alcohol and 3-chloroacrylic acid have also
demonstrated toxicity.  Therefore, these degradates have been included
in this assessment.

Risks to Birds - Risk was estimated for terrestrial animals assuming
exposure through incidental ingestion of soil and inhalation.  The
concentration of 1,3-D in the soil (170.2 ppm) was estimated based on
the maximum application rate per acre and assumed parameters of the area
and depth of soil actually treated within each acre.  Based on these
parameters, only 3.63% of an acre of grape vineyards treated by drip
irrigation; this reduces exposure to terrestrial animals substantially.
Actual exposure to birds of standard body weights were determined using
estimates of daily dry food ingestion and percentage of food ingested as
soil per day.  A composite concentration of the degradates
(3-chloroallyl alcohol and 3-chloroacrylic acid) was estimated as a
percentage of the concentration of 1,3-D in the soil, and exposure to
birds was determined similarly.  Risk due to inhalation was described
using actual measurements of volatilized 1,3-D above soil (0.03 ppm and
4.4 ppm) following application via drip irrigation (6.1 lbs ai/acre) and
soil injection (346 lbs ai/acre) (0.03 ppm and 4.4 ppm, respectively).
The degradates of 1,3-D are not highly volatile, so inhalation risk is
not a concern for the degradates.

Only acute oral and subacute dietary data for 1,3-D are available for
birds, and acute risk was found to be minimal as a result of exposure
through incidental soil ingestion (RQ <0.01).  Chronic risk to 1,3-D
through incidental soil ingestion, acute and chronic risk to 1,3-D due
to inhalation, and risk resulting from incidental ingestion of the
degradates in soil cannot be quantified due to lack of effects data.
Chronic risk resulting from exposure through soil ingestion may be low
due to low expected incidence of exposure to treated soil, so data on
reproductive effects to birds are not needed for further analysis of
chronic risk to birds resulting from the proposed use. However, because
at least one of the degradates has been shown to be more toxic than the
parent compound in several taxa, data are needed to evaluate the acute
risk of 3-chloroallyl alcohol and 3-chloroacrylic acid to birds.

Risks to Mammals – The same estimate of soil and air concentrations of
1,3-D and its degradates used for birds were used for mammals to
determine risks.  Acute and chronic risk were determined to be minimal
as a result of soil ingestion (acute RQ =<0.01, chronic RQ = 0.11 –
0.22) and inhalation (acute RQ <0.01, chronic RQ = 0.002 – 0.22).
EFED does not have an LOC with which to compare inhalation RQs, but
concludes that the RQs likely indicate minimal risk.  The highest RQ of
0.22 results from an estimate of 1,3-D in air above soil resulting from
an application rate and method that is expected to result in greater
volatilization, so the actual value resulting from the proposed use is
likely much lower.

Acute risk as a result of ingestion of 3-chloroallyl alcohol and
3-chloroacrylic acid in soil was determined to be minimal (RQ <0.01 –
0.01).  Chronic data are not available with which to determine the
chronic risk of the degradates to mammals as a result of soil ingestion.
 Since the degradates demonstrate greater toxicity to many taxa than the
parent, chronic risks to mammals may be a concern.

Risks to Terrestrial Plants – Risk due to 1,3-D was found for
dicotyledonous plants inhabiting semi-aquatic areas as a result of
applications made at or above ground level.  Applications made through
drip lines buried 5 cm or 25 cm did not result in EECs in runoff that
posed risk to any terrestrial plants.  Therefore, label restrictions
that require applications of 1,3-D in drip lines buried at least 5 cm
are expected to provide protection to plants in nearby terrestrial and
semi-aquatic areas.  Data for determining these risks for 3-chloroallyl
alcohol, and 3-chloracrylic acid are still under review pending
additional information about methods used in Tier I and II vegetative
vigor and seedling emergence studies conducted with these chemicals.
Questions were raised as to what methods were used to prevent cross
contamination from the Tier I and II 1,3-D plant studies that were
conducted simultaneously.  EFED will provide its findings on these
studies and resulting findings about risk as soon as they are available.

Risks to Freshwater Aquatic Organisms – 1,3-D and its degradates are
expected to occur in surface waters as a result of runoff from the
application sites.  If 1,3-D is applied at or above the ground, as
allowed on the label, acute effects will occur in listed and non-listed
freshwater fish (acute RQ = 0.56), and acute and chronic effects will
occur to listed and non-listed freshwater invertebrates (acute RQ =
6.78, chronic RQ = 1.54), and are expected to occur to listed and
non-listed aquatic-phase amphibians.  Risks to these taxa are not
expected if applications of 1,3-D are made through drip lines buried at
least 5 cm.  Risk to freshwater aquatic plants and algae were determined
to be minimal (RQ = 0.08 – 0.23).  Chronic risks to freshwater fish
could not be determined because the chronic toxicity study with this
taxon was determined to be invalid.  However, since 1,3-D is moderately
toxic to freshwater fish on an acute basis, EFED expects chronic risk to
be a concern.  Submission of a valid early life cycle test with
freshwater fish will clarify this presumption.

Acute risk resulting from exposure to the degradates of 1,3-D
(3-chloroallyl alcohol and 3-chloroacrylic acid) following above ground
applications are minimal for freshwater fish (RQ <0.01 – 0.04),
freshwater invertebrates (RQ <0.01 – 0.02), and aquatic-phase
amphibians.  Risk is expected for listed freshwater aquatic plants and
algae as a result of exposure to runoff containing 1,3-D degradates (RQ
= 0.93 – 26.92) following at- or above-ground applications.  Acute
risk is not expected to any freshwater taxon if applications are made
below ground at the depths modeled.  Data are not available to assess
the chronic risk of 3-chloroallyl alcohol or 3-chloroacrylic acid to
marine/estuarine fish or invertebrates.  Unless data on the chronic
toxicity of the degradates are submitted, these risks remain uncertain.

Risks to Marine/Estuarine Aquatic Organisms –Applications of 1,3-D
made at or above the surface of the soil result in acute risk listed and
non-listed marine/estuarine fish (acute RQ = 0.70) and acute and chronic
risk to marine/estuarine invertebrates (acute RQ = 0.95, chronic RQ =
8.98).  Risk to listed and non-listed marine/estuarine aquatic plants
and algae is minimal (RQ = 0.04 – 0.07) as a result of runoff from
applications at or above the ground.  Chronic risks to marine/estuarine
invertebrates were determined using estimates of chronic values based on
the ratio of acute: chronic toxicity in freshwater invertebrates.  A
similar analysis for marine/estuarine fish could not be conducted due to
lack of chronic toxicity data for freshwater fish.  However, since 1,3-D
is highly toxic to marine/estuarine fish on an acute basis, EFED expects
chronic risk to be a concern.

Acute risk due to exposure to degradates was determined to be minimal
for marine/estuarine aquatic plants and algae (RQ <0.01 – 0.55) based
on toxicity to saltwater diatoms.  No data were available with which to
determine risks of the degradates to marine/estuarine fish or
invertebrates.  However, risks to marine/estuarine species appear to
track those of freshwater species.  Therefore, acute risk may not be
likely for marine/estuarine fish or invertebrates, but until such time
as data are submitted for the chronic toxicity of the degradates,
chronic risks for marine/estuarine species remains uncertain.

Label Restrictions that Reduce Risk – Acute and chronic risks were
identified as a concern to several aquatic taxa due to EECs determined
as a result of ground-level applications (0.1cm depth).  EFED assumes
these EECs are similar to those made through drip lines that are above
the ground, as well.  EECs resulting from applications in drip lines
buried at 5 cm and 25 cm depths do not result in listed or non-listed
species acute or chronic risk concerns in any aquatic taxa.  Therefore,
restricting applications of 1,3-D in drip irrigation to drip lines
buried at least 5 cm would be a protective measure that would minimize
aquatic risks and risk to plants inhabiting semi-aquatic habitats nearby
to areas in which 1,3-D will be used.

II.  	Problem Formulation

Stressor Source and Distribution

Source and Intensity

1,3-Dichloropropene (1,3-D) (Figure 1) is a contact nematicide and
insecticide that is proposed for post-plant application via drip
irrigation in grapes.  The proposed label gives a maximum application
rate of 2.0 gallons of product (17.68 lbs a.i.) per acre, diluted to a
maximum of 200 ppm ai in irrigation water.  The label proposes a maximum
of one in-season application made at least 60 days pre-harvest and one
post-harvest application made within 21 days of harvest.

With a double bond, 1,3-D consists of a cis and trans isomer (Figure 1),
and most formulations contain approximately equal ratios of these
isomers.  1,3-D has two major degradates, 3-chloroallyl alcohol and
3-chloroacrylic acid (Figure 2), that are both mobile, but are not
expected to be as volatile as 1,3-D.  The 3-chloroallyl alcohol is the
major hydrolysis degradation product and is formed at 72 percent of
applied.  The 3-chloroacrylic acid is produced through aerobic soil
metabolism at lower and variable amounts depending on the soil type.  In
studies submitted to the Agency, 3-chloroacrylic acid formed at 1 – 6
percent of applied.  The degradation pathway is presumed to be 1,3-D to
3-chloroallyl alcohol to 3-chloroacrylic acid.  Previous EFED ecological
risk assessments of 1,3-D include a RED (1997) evaluating its use as a
herbicide and nematicide/insecticide fumigant and for a Section 18
Registration for use of Telone in drip irrigation in grapes in
California (completed in 1999)  Some ecological effects data for 1,3-D,
and the acid degradate (1,3-chloroacrylic acid) and the alcohol
degradate (1,3-chloroallyl alcohol) have since been submitted in
response to data gaps identified in these assessments.  This risk
assessment considers 1,3-D and the alcohol and acid degradate substances
as “stressors” for the purposes of determining ecological risk.
Because the 1,3-D and its degradates have different toxicity values and
occur at different concentrations in the environment, EECs and RQs will
be calculated separately for 1,3-D and its degradates where possible.

Figure 1. Molecular structure diagram of 1,3-dichloropropene (1,3-D,
cis- and trans- isomers).

Figure 2. Molecular structure diagrams for 3-chloroallyl alcohol and
3-chloroacrylic acid, the degradates of 1,3-D.

Physical/Chemical/Fate and Transport Properties

The cis and trans isomers of 1,3-dichloropropene (1,3-D) are highly
volatile and mobile under most environmental conditions.  The major
hydrolysis degradates, 3-chloroallyl alcohol and 3-chloroacrylic acid,
are both mobile, but are expected to be less volatile.  The degradates
are stable to hydrolysis in sterile, buffered water, but are quickly
degraded in aerobic aquatic metabolism studies (3-chloroallyl alcohol,
half-life 1.2 days at 25ºC, total 3-chloroacrylic acids, 3.4 days, MRID
44975503).

The primary routes of 1,3-D dissipation in the field appear to be
volatilization, leaching, abiotic hydrolysis, and aerobic soil
metabolism.  In air, 1,3-D does not degrade through direct photolysis;
however, there can be degradation through free-radical (OH and ozone)
processes.  Experimental data for reaction with hydroxyl and ozone,
cited in the EPISuite AOP v1.91 program (Kwok, ESC and Atkinson, R.,
1994) suggest that the half-life for telone in air is on the order of
1.0 to 1.1 days, with the reaction dominated by hydroxyl addition to the
double bond.

In water, hydrolysis is temperature dependent with an increase in
stability at lower temperatures.  This seems to indicate that in warm
climates, degradation will occur more rapidly than in cooler climates.
According to laboratory mobility studies, 1,3-D is mobile in a variety
of soils including loamy sand (Kd= 0.23), sand (Kd= 0.32) and clay (Kd=
0.42 and 1.09.  These mobility data, in addition to ground-water
monitoring information, have clearly demonstrated that 1,3-D is highly
mobile in soil.  Mobility data for 3-chloroallyl alcohol (MRID 44940323)
give a Koc range of 10 to 55, with a mean of 31.

As mentioned above, 1,3-D is highly volatile (vapor pressure 34 mmHg).
The factors influencing the volatility of 1,3-D from a field plot
include, but are not limited to: soil organic matter, wind speed, soil
moisture content, depth of incorporation-injection, soil temperature and
soil porosity.  Studies indicate that approximately 25 percent of
applied volatilizes within the first two weeks after application.  Wind
is a major factor in the dispersion of 1,3-D as higher concentrations
are measured in the air at night when winds are often lighter.  During
the day, an increase in wind velocity also increases vapor dispersion
and lowers the measurable amount of material.

1,3-D has two major degradates: 3-chloroallyl alcohol and
3-chloroacrylic acid.  The 3-chloroallyl alcohol is the major hydrolysis
degradation product and is formed at 72% of applied.  The
3-chloroacrylic acid is produced through aerobic soil metabolism at
lower and variable amounts depending on the soil type.  In studies
submitted to the Agency, 3-chloroacrylic acid formed at 1% - 6% of
applied.  The degradation pathway is presumed to be 1,3-D to
3-chloroallyl alcohol to 3-chloroacrylic acid.

Chemical Identity and Physicochemical Properties

 tc \l2 "Chemical Identity and Physicochemical Properties

Chemical Name

IUPAC

(EZ) - 1,3-Dichloropropene

CAS

1,3-Dichloro-1-propene

CAS Registry No.

542-75-6

Empirical Formula

C3H4Cl2

Molecular Weight

110.97

Synonyms

Not Provided

Formulated Product

Cordon®

The physicochemical properties of 1,3-D are reported in Table 1.

Table 1.  Physicochemical properties for 1,3-D.

physicochemical property

measured value

Solubility (water)

2.2 g/L  at 20(C

vapor pressure

34.3 and 23.0 Torr at 25(C or the (cis) and (trans) isomers,
respectively

Henry’s Law Constant

1.8(10-3 atm-m3-mole-1 (cis) and 1.05(10-3 atm-m3-mole-1 (trans)

Pesticide Type, Class, and Mode of Action

1,3-D is a soil fumigant that exerts toxic action on vital enzymes or
enzyme systems in nematodes.  Substitution of a sulfhydryl, ammonia, or
hydroxyl group with the chlorine in 1,3-D results in restriction of the
enzyme function, leading to paralysis and death.

Overview of Pesticide Usage

The proposed new use is for applications of 1,3-D via drip irrigation in
grapes, which requires lower application rates than the primary uses of
1,3-D as a fumigant applied via soil injection.  These primary uses are
intended for the control of nematodes, although it is also used for
insects as well as Canada thistle (Cirsium arvense) and bindweed
(Concolculus arvensis).  The 1997 EFED RED Chapter also included a
pre-plant application of 1,3-D via drip irrigation to melons at 91 lbs
ai/acre, which was the only crop for which drip irrigation was approved.
 According to the OPP Biological and Economic Analysis Division
Screening Level Usage Analysis dated 9/14/06, an average of
approximately 1,000,000 lbs ai of 1,3-D are applied to melons annually,
representing a relatively small percentage of 1,3-D that is applied in
this manner.  Approximately 300,000 lbs ai of 1,3-D are applied on
average to grapes via fumigation annually. Approximately 1.23 million
acres of grapes were grown throughout the U.S. in 2002.

Ecological Receptors and Measurement Endpoints

For screening level risk assessments, toxicological data gathered on
representative aquatic and terrestrial test species are utilized as
surrogates for broad taxonomic groups.  For this assessment of 1,3-D and
its degradates, these data have mainly been obtained from toxicological
studies submitted to EPA by registrants.  The taxonomic groups
represented by these data are: birds, mammals, plants inhabiting
terrestrial and semi-aquatic environments, freshwater fish and
invertebrates, estuarine/marine fish and invertebrates, and vascular and
non-vascular aquatic plants.  In the absence of toxicity data on
amphibians and reptiles, it is assumed that aquatic-phase amphibians are
approximately as sensitive as fish and also that reptiles and
terrestrial-phase amphibians are approximately as sensitive to birds to
the potential effects of a pesticide.  For both aquatic and terrestrial
receptors, direct acute and direct chronic effects are considered.  The
surrogate test species, assessment endpoints, and measures of effect
typically used for a screening-level risk assessment are presented in
Table 2.  To assess risks to federally listed (i.e., threatened and
endangered) species, all assessment endpoints are measured at the
individual level, which may also provide insights regarding risks at
higher levels of biological organization (e.g., populations).

Table 2.  Ecological Receptors, Assessment Endpoints, and Measures of
Effect Used In Screening-level Risk Assessments

Taxonomic group/test species1	Assessment endpoints	Measures of effect2

Birds3:

Mallard

(Anas playtrhynchos)

Northern bobwhite

(Colinus virginianus)	abundance (i.e., survival, reproduction, and
growth) of individuals and populations	avian acute oral LD50 (mg/kg-bw)

avian subacute dietary 5-day LC50 (mg/kg-diet)

avian reproduction/chronic NOAEC (mg/kg-bw or mg/kg-diet)

Mammals:

Laboratory rat

(Rattus norvegicus)	abundance (i.e., survival, reproduction, and growth)
of individuals and populations	laboratory rat acute oral LD50 (mg/kg-bw)

laboratory rat 2-generation reproduction NOAEC (mg/kg-bw or mg/kg-diet)

Freshwater Animals4:

Bluegill (Lepomis macrochirus)

Rainbow trout

(Oncorhynchus mykiss)

Water flea (Daphnia magna)	survival and reproduction of individuals and
communities 	fish acute 96-h LC50 (mg/L)

fish chronic (early-life stage) NOAEC (mg/L)

invertebrate acute 96-h LC50 (48-h for copepods) (mg/L)

invertebrate chronic (life-cycle) NOAEC (mg/L)

Estuarine/Marine Animals5:

Sheepshead minnow

(Cypridodon variegatus)

Eastern oyster

(Crassostrea virginica)

Mysid shrimp

(Americamysis bahia)	survival and reproduction of individuals and
communities 	fish acute 96-h LC50 (mg/L)

fish chronic (early-life stage) NOAEC (mg/L)

invertebrate acute 96-h LC50 (or EC50 for acute shell deposition and
embryo-larval development tests) (mg/L)

invertebrate chronic reproductive study NOAEC (mg/L)

Terrestrial Plants6:

Monocots - 4 spp.

  e.g., corn (Zea mays)

Dicots - 6 spp.

  e.g., soybean (Glycine max)	perpetuation of individuals and
populations of non-target crop and noncrop species 	monocot seedling
emergence IC25 and NOAEC (lbs ai/A)

monocot vegetative vigor IC25 and NOAEC (lbs ai/A)

dicot seedling emergence IC25 and NOAEC (lbs ai/A)

dicot vegetative vigor IC25 and NOAEC (lbs ai/A)

Aquatic Plants and Algae6:

Vascular - 1 sp.

   duckweed (Lemna gibba)

Non-vascular - 4 spp.

  algae and diatoms

    e.g., green algae

    (Selenastrum capricornutum)	maintenance and growth of standing crop
or biomass	IC50 and NOAEC values for growth rate and biomass
measurements (mg/L)

1 Minimal preferred or required species for screening level risk
assessment.

2 Test guideline measures of effect for designated taxa.

3 Birds are also used as surrogates for reptiles and terrestrial-phase
amphibians

4 Freshwater fish are also used as surrogates for aquatic-phase
amphibians

5 Estuarine/marine toxicity tests are required only if the proposed uses
are expected to result in the active ingredient

   reaching the estuarine/marine environment which is a potential for
the proposed new use.

6 Phytotoxicity tests are required for herbicides and for other
pesticides if the available evidence indicates there may

   be phytotoxicity

Conceptual Model

A conceptual model consists of a written description and visual
representation of the predicted relationships between a stressor, the
potential routes of exposure, and the attribute changes of concern for
the assessment endpoint.  The written description is provided in two
parts, the first part provides the basis for the risk hypotheses
selected for assessment and in the second part the risk hypotheses are
explicitly stated.  Visual representations of the risk hypotheses
assessed in this screening level risk assessment are provided for 1,3-D
applied in drip irrigation, as well as its degradates, in Figure 3.

Risk Hypotheses

The objective of this assessment is to identify risks to the environment
from proposed 1,3-D use on grapes in drip irrigation.   In order for a
chemical to pose an ecological risk, it must reach ecological receptors
in biologically significant concentrations.  An exposure pathway is the
means by which a contaminant moves in the environment from a source to
an ecological receptor.  For this pathway to be complete, it must have a
source, a release mechanism, an environmental transport medium, a point
of exposure for ecological receptors, and a feasible route of exposure.
In addition, the potential mechanisms of transformation must be known,
especially for a chemical whose metabolites/degradates are of greater
toxicological concern than the parent compound.  The assessment of these
pathways thus includes an examination of the sources and potential
migration pathways for constituents, and the determination of potential
exposure routes.

As applied according to the proposed label, 1,3-D and its degradates
will be available in the soil to non-target organisms.  The degradates
are expected to form at the site of application, and are also expected
to move to the same environmental compartments as the parent compound
via the same pathways.  The only exception to this is movement via
volatilization, since the degradates are not expected to volatilize to
the same degree as 1,3-D.

The primary exposure route for terrestrial animals is expected to be
ingestion of soil containing 1,3-D and its degradates at the treatment
site.  Inhalation of volatilized 1,3-D is also expected.  Applications
through above-ground irrigation lines may result in formation of puddles
of treated irrigation water and also contact with the foliage of
terrestrial plants, which could expose terrestrial animals via drinking
water and on-field plant food resources.  The latter two routes are
expected to be minor.  Runoff of 1,3-D and its degradates could also
result in exposure to plants that inhabit terrestrial and semi-aquatic
areas off-site.

Runoff (and to a lesser extent leaching and erosion) is expected to move
significant amounts of 1,3-D and its degradates to nearby water bodies.
Volatilization of 1,3-D from the application site and subsequent
movement via wind is also expected to result in deposition into nearby
water.  Once reaching these environments, some 1,3-D is expected to
volatilize, while the remainder will likely degrade into 3-chloroallyl
alcohol (alcohol degradate) and 3-chloroacrylic acid (acid degradate).
These compounds are expected to remain in the water column.

Exposure to aquatic organisms is likely to occur, and will affect both
fish and invertebrates.  Exposure may occur via ingestion or uptake
through the gills and/or integument.   Aquatic plants are also expected
to be exposed via direct contact or vascular uptake.

Based on the above considerations EFED has formulated the following
hypotheses:

Aquatic exposure: Because 1,3-D and its major acid and alcohol
degradates are highly mobile and soluble, run-off from treated fields
into surface water may result in exposure of aquatic fish and
invertebrates to these substances in the water column.  In addition,
because some grape production occurs in areas adjacent or near
estuarine/marine systems, estuarine/marine fish and invertebrates may be
exposed in addition to freshwater fish and invertebrates from run-off.

Water column exposure-fish and invertebrates: Exposure levels may
potentially result in mortality or decreased reproduction of exposed
listed (endangered or threatened) fish and aquatic invertebrate species
or mortality or decreased reproduction in populations of non-listed fish
and aquatic invertebrate species.

Water column exposure-aquatic plants: Exposure levels in the water
column may potentially result in reduced biomass or standing crop of
aquatic plants.

Sediment: Because of the low Koc and high water solubility of 1,3-D and
its major acid and alcohol degradates, these constituents will be
associated with the water column and not sediment.  Therefore, the
sediment exposure pathway is considered insignificant to risk
determination as compared to water column exposure or incomplete and is
not considered further.

Aquatic food chain: Secondary exposure of primary and secondary
consumers is possible; however, because of its low Kow, 1,3-D is not
expected to cause effects at higher trophic levels through
bioaccumulation. EFED does not have data regarding concentration of
1,3-D, 3-chloroallyl alcohol, or 3-chloroacrylic acid residues taken up
by plants or body burdens in exposed animals, so this exposure pathway
will not be assessed.  However, effects due to secondary exposure are
expected to be minimal.

Avian and mammalian wildlife: The proposed 1,3-D application is drip
irrigation to below, at, or just above the surface soil which will
result in soil residues and potential exposure of avian and mammalian
wildlife.

Residues on food – above surface level drip: Drip irrigation applied
above the surface soil is expected to result in minimal contact with
plant and insect food items on a per acre basis, resulting in a low
probability of exposure through consumption of on-field food items.
Therefore, this pathway will not be considered in this risk assessment.

Residues on food – at or below surface level drip: Because 1,3-D has a
low Kow, bioaccumulation in soil dwelling organisms is not expected, and
the probability of consumption of these organisms by birds and mammals
on a per acre basis is low.  Therefore, although exposure could occur
via this pathway, it is expected to be minimal and is not considered
further in this risk assessment.

Incidental soil ingestion: Wildlife may ingest soil incidentally while
foraging for food within the treated soil or from preening of feathers
or fur after contact with soil.  Exposure levels of 1,3-D and its major
acid and alcohol degradates may potentially result in mortality or
decreased reproduction of an individual exposed listed (endangered or
threatened) wildlife species or reduced survival and reproduction of
exposed non-listed wildlife populations.  This is expected to be the
main pathway for exposure for terrestrial animals.

Inhalation:  Because it is highly volatile, terrestrial animals may be
exposed via inhalation of 1,3-D vapors.  Exposure through inhalation
could result in mortality or decreased reproduction of an individual
exposed listed (endangered or threatened) wildlife species or reduced
survival and reproduction of exposed non-listed wildlife populations.

Terrestrial food chain:  Because of the low Koc and high water
solubility bioconcentration or bioaccumulation of 1,3-D and its major
alcohol and acid degradates up the terrestrial food chain is not
considered a significant exposure pathway or contributor to risk
determination as compared to incidental soil ingestion and is therefore
not considered further.

Aquatic food chain:  Because of the low Koc, high water solubility, and
short-half life bioconcentration or bioaccumulation of 1,3-D and its
major alcohol and acid degradates up the aquatic food chain to
terrestrial piscivorous (fish and shellfish) consumers is considered a
insignificant or incomplete exposure pathway and is therefore not
considered further.

Terrestrial plants:  Because 1,3-D and its major acid and alcohol
degradates are highly mobile and soluble, sheet run-off from treated
fields to non-target soils may result in exposure of terrestrial
non-target plants.  Because the proposed application is by drip
irrigation, no loading of non-target soils by spray drift will occur.
Loading from run-off to non-target soils may potentially result in
mortality or decreased growth of individual listed terrestrial plants or
loss of non-listed populations of terrestrial plants or decrease in
their standing crop or biomass.

Semi-aquatic (riparian) plants:  Because 1,3-D and its major acid and
alcohol degradates are highly mobile and soluble, channel run-off from
treated fields to non-target soils may result in exposure of terrestrial
semi-aquatic non-target plants.  Because the proposed application is by
drip irrigation, no loading of non-target soils by spray drift will
occur.  Loading from run-off to non-target soils may potentially result
in mortality or decreased growth of individual listed semi-aquatic
plants or loss of non-listed populations of semi-aquatic plants or
decrease in their standing crop or biomass.

Diagram

The conceptual model is a generic graphic depiction of the risk
hypotheses identified in the previous section (II.C.1).  It is assumed
that 1,3-D and its major alcohol and acid degradates are capable of
affecting exposed terrestrial and aquatic organisms if environmental
concentrations are sufficiently elevated as a result of proposed label
uses.  Through a preliminary process of examining fate and effects data,
the risk hypotheses and conceptual model has been refined to reflect
possible exposure pathways and the organisms that are most relevant and
applicable to this assessment (Figure 1).  If exposed at sufficient
levels, mortality may occur, as well as sublethal chronic effects, in
addition these direct effects on a taxa may result in indirect effects
(i.e., loss of habitat, food resources) to other taxa.  This assessment
will examine the potential for these effects to occur within the
surrogate taxa with the intent to extrapolate to actual effects within
the environment.

   Analysis Plan

This screening level assessment is based on findings in previous
assessments for 1,3-D, including the 1997 EFED RED Chapter and the 1999
EFED Section 18 Risk Assessment for the use of 1,3-D on grapes in
California, as well as EFED’s standard risk quotient (RQ) methodology.
 Previous risk assessments have also utilized RQs to estimate risk; new
RQs have been calculated here where new model estimates of EECs are
needed or new effects data have been submitted.  An RQ is a ratio of an
estimated environmental concentration (EEC) of a pesticide to a toxicity
value (e.g., LC50), where the EEC is presumed to represent a measure of
exposure.  Acute and chronic RQs for each taxonomic group are compared
to the Agency’s acute and chronic Levels of Concern (LOCs).
Exceedence of an LOC for a taxonomic group triggers a need to consider
regulatory action to mitigate risk.  Table 6 in the Risk
Characterization section summarizes EFED’s LOCs for the various taxa
assessed in screening-level risk assessments.

The assessment for 1,3-D is based on the following use presumptions,
based on the proposed product label and environmental fate data:

because the label states that 1,3-D may be applied through above-ground
irrigation lines, 100% of the 1,3-D applied is assumed to be available
for exposure and transport at the soil surface

the degradates of 1,3-D, 3-chloroallyl alcohol and 3-chloroacrylic acid
are available at the application site and anywhere 1,3-D is transported
except air.

1.	Measures to Evaluate Risk

Terrestrial Exposure tc \l3 "Terrestrial Exposure

Exposure of terrestrial animals can occur via several pathways,
including ingestion of 1,3-D and its degradates in treated soil,
inhalation of vapors above the application site, and consumption of food
items coming into contact with these compounds.  The primary routes of
exposure to terrestrial animals are assumed to be consumption of treated
soil and inhalation.  These can be determined using models for
incidental soil ingestion, estimates of the concentration of 1,3-D and
its degradates in the soil at the site of application, and actual
monitoring data for 1,3-D in air at treated sites.  Other routes of
exposure cannot be quantified, and will be discussed qualitatively in
the risk description.  Exposure to plants inhabiting terrestrial and
semi-aquatic areas can occur via runoff; however, valid terrestrial
plant toxicity data for 1,3-D and its degradates are not available.
Therefore, estimates of 1,3-D in runoff in adjacent terrestrial and
semi-aquatic areas will not be determined.

Aquatic Exposure

Runoff (1,3-D and degradates), and volatilization (1,3-D only) of 1,3-D
and its degradates are likely, thus, use will result in exposure of
these compounds to aquatic animals.  Aquatic exposure will be quantified
using EFED’s PRZM-EXAMS models.  The exposure scenario considered here
represents a pond or other small body of water, such as may be found in
water bodies near sites of application.

2.	Measures of Effect

 tc \l3 "Measures of Effect

Measures of effect are based on the toxicity values generated in the
guideline toxicity studies submitted by the registrant.  When more than
one value is generated (e.g., freshwater fish LC50), the most sensitive
value is used for the screening assessment.  Acute-to-chronic toxicity
ratios can be determined for freshwater organisms and applied to
marine/estuarine animals where data are lacking.  For other taxa,
effects data for 1,3-D are complete, but effects data for its degradates
are not available for birds or marine/estuarine animals.

	3.	Data Gaps

The adequacy of the data submitted by the registrant to support
registration was evaluated relative to Agency guidelines.  The
guidelines for environmental fate have been fulfilled, and there are no
outstanding data needs.  Some ecological effects data are still needed
for a comprehensive evaluation of risks resulting from applications of
1,3-D, especially since the degradates of 1,3-D are more toxic to
several taxa than the parent compound.  These are:

(§71-1) Avian oral LD50 tests with 3-chloroallyl alcohol and
3-chloroacrylic acid

(§122-1 and §123-1) Tier I and II seed emergence and vegetative vigor
tests with 3-chloroallyl alcohol, and 3-chloroacrylic acid (or
information clarifying methods in study already submitted that lead to
upgraded status)

(§72-4) Fish early life stage test with 1,3-D on freshwater fish

(§72-4) Fish early life stage and invertebrate life cycle tests with
1,3-D on marine/estuarine fish and invertebrates

Analysis

Environmental Fate Analysis

1,3-D is highly volatile, very soluble in water, and has a relatively
high Henry’s Law constant.  Thus its fate is expected to be dominated
by evaporation from soil and water, and transfer to air.  In air, 1,3-D
is expected to be attacked by hydroxyl radicals and ozone, with a
disappearance half-life on the order of one day.

Guideline data on aerobic soil metabolism (MRID 42642301) give widely
different results for the two soils tested (Caitlin silt loam half-life
11.8 days, and Fuquay loamy sand soil 59.8 days).

1,3-D is metabolized into 3-chloroallyl alcohol and 3-chloroacrylic
acids in soil and water.  In soil, 3-chloroallyl alcohol reached
5.2-5.3% at 30 days (end of study) in the Caitlin soil, and 23.2-23.6%
at 70 days in the Fuquay soil.  Total 3-chloroacrylic acids reached
1.5-1.9% at 70 days in the Fuquay soil.  The cis- isomer was 4.2-4.3% at
7 days, and trans- isomer was 5.7-5.9% at 20 days in the Caitlin soil.

In a water-sediment system, the alcohol reached 6.4% at day 1 and the
total acids reached 10% on day 7.  Parent half-life in the aquatic
studies was 4.9 days.  For the alcohol, it was 1.2 days, and for total
acids, it was 3.4 days.  Thus telone and its degradates are not expected
to persist in aquatic systems.

Measures of Terrestrial Exposure

Previous risk assessments of 1,3-D have utilized actual measurements of
1,3-D in and above soil for quantitative estimates of terrestrial
exposure through ingestion of treated soil and inhalation of vapors
(MRID 40404401 and 41057701). These measurements have been taken
following applications of 1,3-D fumigant via soil injection at
application rates that are much higher than the proposed use (342 lbs
ai/acre).  The estimated concentration in air above the soil was 4.4
ppm.  Another volatility study is also available (MRID 45296101) that
provides estimates of 1,3-D in the air at 6 inches above the soil
following an application at 6.1 lbs ai/acre.  This application rate is
approximately 1/3 of the proposed use, and resulted in an estimated
concentration in air of 0.03 ppm.  Neither of these values can be used
directly, and the concentration of air does not necessarily have a
linear relationship with application rate.  Therefore, these values will
be sued to bracket the actual exposure resulting from the proposed use.

The field dissipation study does not necessarily provide a good estimate
of exposure through incidental soil ingestion since the application
method differs significantly.  As an alternative, an estimate of the
exposure to terrestrial animals in the soil was derived based on the
maximum application rate per acre (17.68 lbs) and the estimated volume
of soil actually treated.  An area with diameter of 2 feet was assumed
to be treated beneath each vine, assuming that two drip emitters per
vine deliver 1,3-D to the soil as recommended on the label.  A 9-inch
wetting depth in dry soil was also assumed; the actual value may vary
based on soil type and conditions, but this value was assumed to be a
reasonable conservative estimate.  Based on growing recommendations, row
spacing and vine spacing were assumed to be 10 feet and 7 feet,
respectively.  This configuration results in 505 vines per acre, giving
an actual area treated of 1586.5 ft2, resulting in 0.0114 lbs a.i./ft2.
Using the above parameter estimates and assuming a soil bulk density of
1.4 g/cm3 (taken from the New York grape PRZM-EXAMS scenario), the
concentration in the soil at each vine is determined to be 170.2 ppm.
This estimate is higher than the 130 ppm estimate used in previous risk
assessments, but consideration is also made for the likelihood of
encounter on a per acre basis.  Submission of a field dissipation study
that is more appropriate for the proposed application method and rate
would reduce uncertainty associated with the use of this exposure
estimate as well as the exposure estimate for inhalation.

To determine the amount of 1,3-D exposure through incidental soil
ingestion, this risk assessment employs information from Beyer et al.
(1994) as used in the previous risk assessments for 1,3-D.  To update
the approach for incidental soil ingestion and dietary risk currently
used by EFED, percentages of body weight consumed as diet were
recalculated with allometric equations used in the TREX terrestrial
exposure spreadsheet model.   These equations are available in EPA’s
Wildlife Exposure Factors Handbook, as well as estimated percentages of
diet consumed as soil per day.  The maximum estimates for soil
consumption for birds and mammals were used, and these were 30% for
birds and 17% for mammals.  Also in keeping with current EFED policy for
assessment of dietary risks, the LD50 for birds and mammals was adjusted
for standard body weights (see TREX User’s Guide).   Exposure
estimates based on dietary intake for birds and mammals are provided in
Tables 9-11, in the Risk Characterization Section.

Exposure to terrestrial wildlife via drinking water was determined to be
a potentially significant route of exposure in previous risk
assessments, although there was no way to estimate the amount that would
occur in drinking water.  According to the proposed label, formation of
puddles during treatment is not allowed, and treatment must be
discontinued if it occurs.  However, terrestrial animals may be exposed
if a rain event occurs post application and 1,3-D partitions into the
water.  EFED is currently developing a model to address this concern,
and it should be examined in the future.  Risk due to exposure in this
medium will not be addressed in this risk assessment.

The standard method for determining risk to terrestrial animals in
EFED’s screening level risk assessments utilizes EECs available to
this taxon in on-field plant food.  The standard model based on the
Kenaga nomogram does not apply to application of 1,3-D in drip
irrigation.  Since this route of exposure is expected to be minor, risk
via consumption of on-field plants will not be determined.  Because
1,3-D has a low Kow, it is also unlikely that it will bioaccumulate in
soil macroinvertebrates.  Therefore, this source of food for terrestrial
animals will not be examined.

Exposure of non-target plants inhabiting nearby terrestrial and
semi-aquatic areas to 1,3-D via runoff was determined with EFED’s
TERRPLANT spreadsheet model (version 1.2.1).  This model calculates the
expected exposure value in lbs a.i./acre that reaches nearby terrestrial
areas via sheet runoff and nearby semi-aquatic areas via channel runoff.
 An estimate of exposure due to drift is also added into all exposure
estimates, which does not exactly apply to applications of 1,3-D via
drip irrigation.  However, since volatilization of some unknown amount
of 1,3-D is expected from this application method, the amount from drift
was left in the exposure estimate.  Exposure estimates using this model
assuming 0, 5, and 25 cm incorporation, as used in the aquatic exposure
estimates (see below), are presented in Table 14 in the Risk
Characterization Section.  Tiers I and II studies with the degradates of
1,3-D (3-chloroallyl alcohol and 3-chloroacrylic acid) are still being
evaluated, pending further information about the methods used to
determine the effects of these chemicals on non-target terrestrial
plants.  When this information is provided, EFED will determine whether
calculating exposure estimates is necessary and will then provide
estimates of risk from these compounds.

Acute oral toxicity data for mammals are available for the degradates of
1,3-D.  The EFED RED Chapter for 1,3-D indicated that as much as 78% of
the parent can be converted to degradates in the soil.  Therefore, a
concentration of 132.8 ppm will be used as an estimate for the
concentration of degradates in the soil. Daily dose from soil ingestion
will be estimated with the same methods as for the parent.  Since the
LD50s for both degradates are identical for mammals, use of this
percentage as an estimate of composite degradate concentration is
appropriate, assuming these compounds have additive toxicity.  Exposure
estimates for mammals are provided in Table 12 in the Risk
Characterization Section.

Since the degradates are not highly volatile, inhalation exposure will
not be determined.  Since degradates may partition into water in
on-field puddles following rain events, this potential risk should be
examined in the future when a model is available to estimate exposure.

Measures of Aquatic Exposure

Exposure to parent 1,3-D was estimated using the tier II model
PRZM-EXAMS.  Two scenarios, New York grapes, and California grapes
(non-irrigated) were used.  Exposure estimates from the California
scenario are expected to be underestimated, due to the lack of
irrigation in the scenario.

Exposure to the degradates 3-chloroallyl alcohol and 3-chloroacrylic
acid was estimated by multiplying the PRZM-EXAMS results for the parent
by the maximum formation of the degradates in the parent aerobic aquatic
metabolism study (MRID 44975503).  In that study, the alcohol reached a
maximum of 6.4% at 1 day, and the acids reached 10% at 7 days.

A sensitivity analysis was performed to determine which parameters had
the most influence on the aquatic EECs.  Using the Mississippi cotton
scenario, it was found that the volatility parameters (vapor pressure,
Henry’ Law constant, diffusion coefficient in air, and enthalpy of
vaporization) reduced EECs by approximately 75% from 201 ppb (peak) to
49 ppb (peak).  Alternative values of soil, water, and benthic
half-lives had almost no influence on the EEC.  The input value for soil
metabolism (97.6 days) is higher than either of the two studies (11.8
and 59.8 days), because of the large standard deviation, and the small
number of values (2) that went into calculating the upper 90th
percentile on the mean value.

	The following input parameter values were used.

Table 3. PRZM and EXAMS  Inputs for Telone (1,3-D)

MODEL INPUT VARIABLE

INPUT VALUE

   SOURCE

Application Rate (lb a.i./acre)

17.68	Proposed Label

Maximum Number of Applications

2	Proposed Label

Interval between Applications

60 days (pre-harvest interval)	Proposed Label

Soil Organic Carbon Partitioning Coefficient (Koc)

41

Carleton, 1998. Tier II Exposure Assessment

Aerobic Soil Metabolism

t1/2 = 97.6

Carleton, 1998. Tier II Exposure Assessment

Aerobic Aquatic Metabolism

t1/2 = 195.2

Carleton, 1998. Tier II Exposure Assessment

Anaerobic Aquatic Metabolism

t1/2 = 60

Carleton, 1998. Tier II Exposure Assessment

Water Solubility

2500 mg/L @ 20oC

Carleton, 1998. Tier II Exposure Assessment

Henry’s Law Constant

Vapor Pressure

3.55E-3 atm-m3mole-1

34 mmHg

Air Diffusion Coefficient

Enthalpy of Vaporization

7227 cm day-1

20 Kcal/mole (default)

Carleton, 1998. Tier II Exposure Assessment

Application Method

Drip or buried irrigation, 0.1, 5, or 25 cm incorporation depth

CAM 4

Ecological Effects Characterization

	1. Ecological Effects of 1,3-D

Effects characterization describes the potential adverse effects a
pesticide can produce in a terrestrial or aquatic organism.  This
characterization is typically based on the studies that describe acute
and reproductive/chronic effects toxicity information for various taxa.
The complete record of data available for 1,3-D and its degradates is
presented in Appendix II.  Since only endpoints from the most sensitive
species are used to estimate risk, only data utilized in this risk
assessment are presented below.

	Terrestrial Animals

Table 4 presents toxicity values for birds, mammals, and beneficial
insects that are used in this assessment to determine risk to 1,3-D.
These values were chosen because they were either the only values
available or represented the greatest sensitivity among the available
values.  1,3-D is moderately toxic to birds on an acute oral basis, and
practically non-toxic (LC50 > 10,000 ppm) to birds on a subacute dietary
basis.  Acute oral toxicity values will be used to determine risk via
incidental ingestion of soil and in drinking water because the subacute
dietary value is inconsistent with the acute oral value and may not
adequately depict a dose response (see Appendix II).  Chronic toxicity
data are not available for birds.

Acute and chronic oral/dietary and inhalation toxicity values are
available for mammals from studies conducted on laboratory species.
Based on the toxicity values in these tests, 1,3-D is slightly toxic on
an acute oral basis to wild mammals, assuming that the laboratory rat
adequately represents their sensitivity. These species are assumed to be
representative of wild mammals.

 value was mistaken to be 6.6 μg/bee (the LD50 was correctly identified
in the study’s DER).  The value is actually higher, and indicates that
1,3-D is practically non-toxic to honey bees.

Table 4. Acute toxicity values for 1,3-D to terrestrial animals utilized
for estimating risk.

Species	Test Type and Toxicity Value	Toxicity Classification	MRID	Study
Classification

Birds

Northern bobwhite

(Colinus virginianus)	Acute Oral

LD50 = 152 mg/kg	Moderately toxic	00118938	Acceptable

Mammals

Laboratory rat

(Rattus norvegicus)	Acute Oral

LD50 = 224 mg/kg (Females)	Moderately toxic1	40220901	Acceptable

Laboratory rat

(Rattus norvegicus)	13-Week Feeding Study2

NOAEC = 5 mg/kg/day	N/A	42954802	Acceptable

Laboratory rat

(Rattus norvegicus)	Acute Inhalation

LC50 = 729 ppm

(3.31 mg/L) (Males & Females)	N/A	40220903	Acceptable

Laboratory rat

(Rattus norvegicus)	Developmental Inhalation

NOAEL Maternal = 20 ppm

NOAEL Developmental = 60 ppm	N/A	00144715

00152848	Acceptable

Insects

Honey bee

(Apis mellifera)	Acute Contact

 > 60.43 μg/bee	Relatively nontoxic	00028772

00018842	Acceptable

1Based on criteria established for wild mammals.

2A 2-generation rat reproduction study is not available for 1,3-D.

	Terrestrial Plants

Tiers I and II seedling emergence and vegetative vigor studies were
submitted for 1,3-D, and these studies were determined to be acceptable.
 The EC25 and NOAEC values for the most sensitive monocotyledon and
dicotyledon species are presented in Table 5.

Table 5.  Terrestrial plant toxicity data for 1,3-D.

Type of Test and Species	EC25 (ppm)1

	NOAEC (ppm)1

	Most Sensitive Endpoint

22-day Seedling Emergence

Onion (Monocot.)	>80

(>11.69 lbs a.i./acre)	80

(11.69 lbs a.i./acre)	None

22-day Seedling Emergence

Tomato (Dicot.)	33

(4.81 lbs a.i./acre)	15

(2.19 lbs a.i./acre)	Shoot weight

22-day Vegetative Vigor

Onion 	24

(3.5 lbs a.i./acre)	15

(2.19 lbs a.i./acre)	Shoot length

22-day Seedling Emergence

Tomato	47

(6.86 lbs a.i./acre)	28

(4.08 lbs a.i./acre)	Shoot weight

1The report provides toxicity levels tested and toxicity values in units
of ppm.  These were converted to lbs a.i./acre by multiplying the
concentration in ppm (mg/L) by the volume of treatment solution used to
treat each plant (0.35 L).  Mass was divided by the area of each pot
(6.5 in diameter) and the resulting value was converted to pounds/acre.

	Aquatic Animals

Table 6 presents toxicity information for aquatic animals.  Data were
available for several species of freshwater fish, and all indicated that
1,3-D is moderately toxic to this taxon.  The walleye was the most
sensitive species.  Data were more limited for other freshwater and
marine/estuarine taxa, but all acute data indicated that 1,3-D is highly
toxic or very highly toxic on an acute basis.  Chronic data for
freshwater species indicate the potential for chronic effects at low
concentrations.  Chronic data were not available for marine/estuarine
species; however, these could be estimated based on the ratio of acute
to chronic toxicity values for freshwater fish and invertebrates.  These
estimates are tentative, however, pending a decision about the status of
freshwater fish and invertebrate chronic toxicity studies.

Table 6. Acute and chronic toxicity of 1,3-D to freshwater and
marine/estuarine fish and invertebrates.

Species	Test Type and Toxicity Value	Toxicity Classification	MRID	Study
Classification

Freshwater Fish

Walleye

(Stizostedion vitreum)	96-Hour acute (static)

LC50 = 1.08 ppm	Moderately toxic	40098001	Supplemental

Freshwater Invertebrates

Water flea

(Daphnia magna)	48-Hour acute (static)

LC50 = 0.09 ppm	Very highly toxic	40098001	Supplemental

Water flea

(Daphnia magna)	21-Day chronic (flow-through)

NOAEC = 0.07 ppm	N/A	45007501	Supplemental

Marine/Estuarine Fish

Sheepshead minnow

(Cyprinodon variegatus)	96-Hour acute (flow-through)

LC50 = 0.87 ppm	Highly toxic	44843901	Acceptable

Marine/Estuarine Invertebrates

Eastern oyster

(Crassostrea virginica)	96-Hour acute (flow-through)

EC50 = 0.64 ppm	Highly toxic	44843903	Acceptable

Marine/Estuarine Invertebrate	Chronic value estimated from freshwater
invertebrate acute:chronic ratio

NOAEC = 0.02 ppm	N/A	N/A	N/A

	Aquatic Plants

Since the 1998 RED was signed, a full battery of Tier I and Tier II
toxicity tests on aquatic plants was submitted.  1,3-D is currently
registered as a herbicide, and is expected to move offsite.  Therefore,
nontarget plants could be affected from 1,3-D applications to grapes.
Results of these tests are presented in Table 7.  Among the freshwater
plants and algae tested in acceptable/supplemental studies, the
freshwater diatom (Navicula pelliculosa) was determined to be the most
sensitive species based on the EC50, although the EC5 had to be roughly
estimated for this species since data were not provided in order to
calculate a NOAEC.  The EC50 for the saltwater diatom (Skeletonema
costatum) is comparable.

Table 7. Toxicity of 1,3-D to freshwater and marine/estuarine algae.

Species	EC50 (ppm) (nominal/measured)	EC5/ NOAEC (ppm)
(nominal/measured)	MRID 	Study Classification

Freshwater diatom (Navicula pelliculosa)	7.9 (120-hour) (nominal)	EC5 =
2.7 ppm1

(96-hour)

(nominal)	44843909 	Supplemental1

Saltwater diatom (Skeletonema costatum)	15.5 (120- hour) (nominal)	NOAEC
= 8.8

 (120-hour)

(nominal)	44843910 	Acceptable

1Study classified as supplemental because raw data were not provided in
order to perform the proper statistical tests to estimate toxicity
values.  The EC5 was estimated using the program Nuthatch.

	Incidents Reported for 1,3-D

A review of the EIIS database for ecological incidents involving
1,3-Dichloropropene was conducted on January 31, 2007.  The database
contained six incidents involving plants and one incident involving
aquatic animals.  In all cases, 1,3-D was linked with relative certainty
(high probability in the aquatic case) to the incident.

Incidents with plants involved crop plants treated directly with 1,3-D.
Crops with reported damage included grapes, potatoes, apples, turf, and
watermelon.  These incidents highlight the herbicidal qualities of
1,3-D, and provide further evidence that 1,3-D may be toxic to
non-target plants inhabiting areas near treatment sites.

The incident involving aquatic animals (# I016738-016) was determined to
be an accidental misuse wherein 1,3-D was applied to strawberries
through in-line fumigation, according to the report.  In this case, a
faulty irrigation valve caused 1,3-D to leak and run off the treated
field into a nearby stream.  The incident resulted in mortality to
>1,000 fish, which included carp, catfish, crawfish, hitch, rainbow
trout, striped bass, Sacramento blackfish, sculpin, sucker, and other
unknown species.  Residue analysis of water and gill samples confirmed
exposure to 1,3-D.

Ecological Effects of 3-Chloroallyl Alcohol and 3-Chloroacrylic Acid

	Terrestrial Animals and Plants

Data are not available with which to estimate the risks of 3-chloroallyl
alcohol or 3-chloroacrylic acid to birds, so these risks will not be
addressed in this assessment.  Two acute oral studies with laboratory
rats have been submitted, which indicated an LD50 of 91 mg/kg for both
degradates (MRID 44843905 and 44940309).  This value would classify the
degradates of 1,3-D as moderately toxic to wild mammals if their
sensitivity is comparable.

Tier I and II terrestrial plant studies have been submitted and with
3-chloroallyl alcohol and 3-chloroacrylic acid (MRID 45007502), and the
status of these studies is pending because of questions raised as to its
validity.  These studies were conducted simultaneously with the Tier I
and II tests for 1,3-D and in the same greenhouse.  The study report
does not provide clear evidence that the effects of the volatility of
1,3-D on the plants in the degradate studies were controlled.  These
questions are being investigated, and EFED expects to resolve them soon.
 EFED will communicate its findings on the validity of the studies and
resulting estimates of risk as soon as they become available.

	Aquatic Animals and Plants

Concerns were raised in previous risk assessments for the potential risk
of the degradates of 1,3-D to aquatic animals and plants.  Since the
1998 RED was signed, several toxicity studies were submitted with which
to estimate the risk to freshwater fish, invertebrates, and plants, as
well as a non-vascular marine/estuarine alga species.  For freshwater
fish and invertebrates, the alcohol degradate was shown to be more toxic
than both the parent compound and the acid degradate.  For aquatic
plants, the relationship between these compounds was more variable,
which precludes a similar generalized conclusion for this taxon (Table
8).

The approach used in previous risk assessments estimated the composite
concentration of 3-chloroallyl alcohol and 3-chloroacrylic acid that
would occur in aquatic habitats.  In this assessment, risks to each
degradate will be addressed separately.  The most sensitive species
among the freshwater aquatic plants/algae was chosen to assess the risks
to this taxon.  A complete record of the toxicity data is provided in
Appendix II.

Table 8.  Acute toxicity values for freshwater fish and invertebrates
exposed to degradates of 1,3-D.

Species	Test Material	Endpoint Value

(Test duration)	Toxicity Category	MRID	Study Classification

Rainbow Trout (Oncorhynchus mykiss)	3-Chloroallyl alcohol	LC50 = 0.986
ppm

NOAEC = 0.303 ppm

(96 hours)	Highly Toxic	44940306 	Supplemental

Rainbow trout

(Onchorynchus mykiss)	3-Chloroacrylic acid	LC50 = 69.5 ppm

NOAEC = 49.2 ppm

(96 hours)	Slightly Toxic	44940307	Acceptable

Waterflea (Daphnia magna)

3-Chloroallyl alcohol

	EC50 = 2.3 ppm

NOAEC = 4.2 ppm

(48 hours)	Moderately Toxic	44843902 	Supplemental

Waterflea (Daphnia magna)	3-Chloroacrylic acid	EC50 = 55.0 ppm

NOAEC = 24.9 ppm

(48 hours)	Slightly Toxic	44940308	Acceptable

Duckweed

(Lemna gibba)

3-Chloroallyl alcohol

	EC50 = 1.694 ppm

NOAEC = 0.042 ppm

(14 days)	N/A	44940320 	Supplemental

Duckweed

(Lemna gibba)	3-Chloroacrylic acid	EC50 = 0.22 ppm

EC05 = 0.0023 ppm

(14 days)	N/A	45007504 	Supplemental

Saltwater diatom (Skeletonema costatum)	3-Chloroallyl alcohol	EC50 =
0.248 ppm

NOAEC = 0.071 ppm

(120 hours)	N/A	44940316	Acceptable

Saltwater diatom (Skeletonema costatum)	3-Chloroacrylic acid	EC50 = 50.2
ppm

NOAEC = 23.7 ppm

(96 hours)	N/A	45007503 	Supplemental

Risk Characterization

Risk Estimation

Risk estimation is the integration of effects and fate data, resulting
in an estimate of potential mortality or chronic/reproductive effects to
non-target animals and plants.  Risk is determined by calculating a risk
quotient (RQ), which is then compared to a level of concern consistent
with listed and non-listed species, acute and chronic risks, and
restricted and non-restricted uses.  Table 9 summarizes the equations
for calculating RQs for each taxon of concern and their respective LOCs.

Table 9. Risk Presumption LOC Values and Associated Formulas for RQ
Calculations.

Risk Presumption	RQ	LOC

Birds and Wild Mammals

Acute Risk1	EEC2 (ppm) / LC50 (ppm) or EEC (mg/kg-bw/d) / LD50
(mg/kg-bw/d)	0.5

Acute Restricted Use1	EEC (ppm) / LC50 (ppm) or EEC (mg/kg-bw/d) / LD50
(mg/kg-bw/d)	0.2

Acute Endangered Species1	EEC (ppm) / LC50 (ppm) or EEC (mg/kg-bw/d) /
LD50 (mg/kg-bw/d)	0.1

Chronic Risk1	EEC (ppm) / NOAEC (ppm) or EEC (mg/kg-bw/d) / NOAEL
(mg/kg-bw/d)	1.0

Aquatic Animals

Acute Risk	EEC (ppm) / (LC50 (ppm) or EC50 (ppm))	0.5

Acute Restricted Use	EEC (ppm) / (LC50 (ppm) or EC50 (ppm))	0.1

Acute Endangered Species	EEC (ppm) / LC50 (ppm) or EC50	0.05

Chronic Risk	EEC (ppm) / NOAEC (ppm)	1.0

Terrestrial Plants and Plants Inhabiting Semi-Aquatic Areas

Acute Risk	EEC (lbs ai/A) / EC25 (lbs ai/A)	1.0

Acute Endangered Use	EEC (lbs ai/A) / (EC05 or NOAEC (lbs ai/A))	1.0

Aquatic Plants

Acute Risk	EEC (ppm) / EC50 (ppm)	1.0

Acute Endangered Species	EEC (ppm) / (EC05 or NOAEC (ppm))	1.0

1 For mammals and birds RQs can either be calculated based on
concentration of the ai in the diet (ppm) where the dietary level from
the laboratory study is adjusted for the body weight of representative
exposed mammals or birds or compare normalized dose values in terms of
milligram of ai per kilogram body weight per day (mg/kg-bw/d).

	Terrestrial Animals

Previous risk assessments did not calculate RQs for terrestrial animals
using standard methods.  Instead, RQs were calculated using estimates of
incidental soil ingestion at a maximum rate of 30% and 17% of dietary
intake for birds and mammals, respectively, and the estimated soil
concentration of 170.2 ppm a.i. 1,3-D.  This value will be used to
calculate exposure and risk in the analyses below, and will be adjusted
assuming that foraging occurs in a random walk and only 3.64% of the
soil ingested contains 1,3-D.

Birds

Acute Risk from Soil Ingestion - Based on the above information, and
using current EFED policy of adjusting LD50 and dietary intake for
standard bird body weights of 20g, 100g, and 1000g, RQs for ingestion of
soil containing 170.2 ppm are presented in Table 10.  This analysis
assumes that birds would only consume 3.64% of the treated soil on an
acre of grape vineyard, since this is the percentage of area estimated
to actually be treated.  This analysis also rests on the assumption that
the LD50 scales for body weight assuming the default scaling factor of
1.15 for standard EFED assessments of dietary risk (see TREX User’s
Guide).  Based on these calculations, no avian LOCs are exceeded.

Table 10.  RQs for birds resulting from incidental ingestion of soil
containing 1,3-D.

Soil Conc. 	Body Weight	Grams of food ingested per day1	Grams of soil
ingested per day2	Estimated Dose (mg/kg-bw)3	Adjusted LD50 (mg/kg-bw)4
RQ

170.2 ppm (estimated)	20g	5	1.5	0.46	109.51	<0.01

	100g	13	3.9	0.24	139.41	<0.01

	1000g	58	17.4	0.11	196.92	<0.01

1Determined from percentage of body weight consumed per day; based on
allometric equations for all birds used in the TREX model.

2Estimated as a percentage of food consumption based on Beyer et al.
1994, maximum 30% of diet consumed as soil.

3Assuming that the animal conducts foraging along a random walk and
3.64% of soil ingested contains 1,3-D. Calculation is: (Soil Conc. * g
soil ingested/day * 0.0364)/bodyweight (kg).

4Based on default Mineau scaling factor of 1.15 and the assumption that
diet contains 80% water as used in assessments of avian risks from
consumption of on-field plants.  See T-REX User Guide.

Acute Inhalation Risk – Data are not available with which to determine
the risk to birds via inhalation, although this route is likely an
important contributor to overall exposure.  However, since inhalation
risk for mammals is low, EFED expects that risk to birds via this route
is probably minimal.  These were also the findings of previous risk
assessments.

Chronic Risk - Chronic dietary or inhalation toxicity data for birds is
not available for 1,3-D, so EFED cannot quantitatively assess the
chronic risk resulting from the proposed use.

		Mammals

Acute Risk from Soil Ingestion – The previous risk assessments on
1,3-D utilized a mouse acute oral LD50 of 640 mg/kg; however, an acute
oral rat study is available that indicates a lower rat LD50 value of 224
mg/kg. Based on the lower value and using the same approach as above for
birds the maximum acute RQ for herbivorous mammals using an EEC of 170.2
ppm is <0.01 (Table 11).  This analysis also assumes that 3.64% of
foraging occurs in treated areas, which greatly reduces exposure.

Table 11.  RQs for wild mammals resulting from incidental ingestion of
soil containing 1,3-D.

Soil Conc.	Body Weight	Grams of food ingested per day1	Grams of soil
ingested per day2	Estimated Dose (mg/kg-bw)3	Adjusted LD50 (mg/kg)4	RQ

170.2 ppm (estimated)	15g	3.0	0.28	0.12	492.31	<0.01

	35g	5.0	0.47	0.08	398.33	<0.01

	1000g	31.0	2.91	0.02	172.29	<0.01

1Determined from percentage of body weight consumed per day; based on
allometric equations for all birds used in the TREX model.

2Estimated as a percentage of food consumption based on Beyer et al.
1994, maximum is 9.4% of diet consumed as soil.

3Assuming that the animal conducts foraging along a random walk and
3.64% of soil ingested contains 1,3-D. Calculation is: (Soil Conc. * g
soil ingested/day * 0.0364)/bodyweight (kg).

4Assumes a set bodyweight of 350 g for the test animals and assumption
of diet containing 80% water.  See T-REX User Guide.

Acute Inhalation Risk - Among the acute inhalation studies that are
available for 1,3-D, the lowest LC50 is 729 ppm, which is much higher
than the EEC of 4.4 ppm used in previous risk assessments (following an
application of 1,3-D via soil injection at 346 lbs ai/acre).  A
volatility study following application via drip irrigation in grapes is
also available at which 1,3-D was applied at 6.1 lbs ai/acre (MRID
45296101).  This is approximately 1/3 of the rate proposed for the new
use.  In this study, 1,3-D was found at a concentration of 0.03 ppm 6
inches above the soil at 24 hours post-application.  Based on these
values, RQs for inhalation for mammals would be within the range of
<0.001 – 0.006.  EFED does not have an LOC to which to compare the RQ
for inhalation; however, it is likely that these values do not present
significant risk to mammals.

Chronic Ingestion Risks – The EFED RED Chapter did not include
consideration for chronic risks because of the rapid dissipation of
1,3-D and because it was applied only once in a growing season.  The
Section 18 for grapes dismissed chronic risks without explanation.
However, based on the NOAEC from the 13-week feeding study, converted to
a NOAEL and adjusted for body weight as in standard dietary risk
assessments, RQs for small-, medium-, and large-sized mammals do not
exceed the chronic LOC (Table 12) assuming the maximum soil ingestion
rate of 17% of the diet.  The exposure estimate assumes that the mammals
would forage in a random walk over a treated grape vineyard, in which
only 3.64% of the area containing vines is actually treated with 1,3-D.
Therefore, the exposure estimates have been adjusted assuming that only
3.64% of the soil ingested contains 1,3-D

 Table 12.  Chronic RQs for wild mammals resulting from incidental
ingestion of soil containing 1,3-D.

Soil Conc.	Body Weight	Grams of food ingested per day1	Grams of soil
ingested per day2	Estimated Dose (mg/kg-bw)3	Adjusted NOAEL (mg/kg)3	RQ

170.2 ppm (estimated)	15g	3.0	0.28	0.12	0.55	0.22

	35g	5.0	0.47	0.08	0.44	0.18

	1000g	31.0	2.91	0.02	0.19	0.11

1Determined from percentage of body weight consumed per day; based on
allometric equations for all birds used in the TREX model.

2Estimated as a percentage of food consumption based on Beyer et al.
1994, maximum is 9.4% of diet consumed as soil.

3Assuming that the animal conducts foraging along a random walk and
3.64% of soil ingested contains 1,3-D. Calculation is: (Soil Conc. * g
soil ingested/day * 0.0364)/bodyweight (kg).

4Assumes a set bodyweight of 350 g for the test animals and assumption
of diet containing 80% water.  See T-REX User Guide.

Chronic Inhalation Risk – Based on the estimates of 1,3-D in the air
above the soil used for the acute inhalation risks to mammals, estimated
RQs based on a maternal NOAEC of 20 ppm would be 0.22 using the maximum
estimate of 4.4 ppm following soil injection at 346 lbs ai/acre. Using
the lower estimate of 0.03 ppm from the drip irrigation study, the
highest RQ based on the maternal NOAEC is 0.002.  EFED does not have a
LOC with which to compare these values; however, it is unlikely that
risk as a result of chronic exposure via inhalation is a concern for the
proposed new use.

Degradates – Acute risk from ingestion of soil containing degradates
was determined using the rat acute oral LD50 value of 91 mg/kg.  Based
on this value, the RQs calculated for mammals of standard body sizes do
not exceed any mammal LOCs (Table 13).  Chronic data with the degradates
in mammals is not available, so these risks cannot be determined.

Table 13.  RQs for wild mammals resulting from incidental ingestion of
soil containing degradates of 1,3-D.

Soil Concentration	Body Weight	Grams of food ingested per day1	Grams of
soil ingested per day2	Estimated Dose (mg/kg)3	Adjusted LD50 (mg/kg)4	RQ

132.8 ppm

(78% transformation of parent – composite degradate estimate)	15g	3.0
0.28	0.09	492.31	<0.01

	35g	5.0	0.47	0.06	398.33	<0.01

	1000g	31.0	2.91	0.15	172.29	<0.01

1Determined from percentage of body weight consumed per day; based on
allometric equations for all birds used in the TREX model.

2Estimated as a percentage of food consumption based on Beyer et al.
1994, maximum is 9.4% of diet consumed as soil.

3Assuming that the animal conducts foraging along a random walk and
3.64% of soil ingested contains 1,3-D. Calculation is: (Soil Conc. * g
soil ingested/day * 0.0364)/bodyweight (kg).

4Assumes a set bodyweight of 350 g for the test animals and assumption
of diet containing 80% water.  See T-REX User Guide.

	Terrestrial Plants

1,3-D - 1,3-D is utilized as a herbicide and it has demonstrated the
capacity to damage crop plants, therefore, effects to non-target plants
are likely.  RQs for plants in terrestrial and semi-aquatic areas nearby
to areas treated with 1,3-D exceed the LOCs for listed and non-listed
dicotyledonous species inhabiting semi-aquatic areas if 1,3-D is applied
at or above ground level (Table 14).  RQs for monocotyledonous species
do not exceed the LOC under any scenario, and no RQs exceed any LOCs if
1,3-D is applied below ground at 5 cm or 25 cm.  Care must be taken in
interpreting these values, however, because this model cannot account
for 1,3-D that volatilizes from underground applications.  The model
also only assumes that 5% of the amount of 1,3-D applied is lost in
runoff, and the actual value for this is not known.

Table 14.  Exposure and risk to non-target listed and non-listed plants
inhabiting terrestrial and semi-aquatic areas adjacent to areas treated
with 1,3-D.  Values in bold indicate an exceedance of the plant LOC of
1.0.

	Adjacent Terrestrial Areas	Adjacent Semi-Aquatic Areas

Listed Species RQ	Non-Listed Species RQ

Listed Species RQ	Non-Listed Species RQ

Irrigation Line Depth (cm)	EEC

(lbs ai/acre)	Mono.	Dicot	Mono.1	Dicot	EEC

(lbs ai/acre)	Mono.	Dicot	Mono.1	Dicot

0	1.06	0.09	0.48	<0.09	0.22	9.02	0.77	4.12	<0.77	1.87

5	0.35	0.03	0.16	<0.03	0.07	1.94	0.17	0.89	<0.17	0.40

25	0.21	0.02	0.10	<0.02	0.04	0.53	0.05	0.24	<0.05	0.11

1Values are given as less than the value indicated because the
monocotyledon seedling emergence EC25 is >11.69 lbs ai/acre.

Degradates – The degradates of 1,3-D are mobile, and thus have the
potential to come in contact with plants inhabiting nearby terrestrial
and semi-aquatic areas.  The effects of 3-chloroallyl alcohol and
3-chloroacrylic acid are as yet undetermined due to questions raised
about methods used in the Tier I and Tier II studies for these
chemicals.  Specifically, the studies were conducted at the same time
and location as the 1,3-D studies and methods to control the effects of
volatilized 1,3-D on plants in the degradate studies were not given.
These questions are currently being investigated, and EFED will provide
its findings as soon as they are available.

	Aquatic Animals

	Freshwater Fish and Invertebrates

Acute Risk to 1,3-D - Peak values from PRZM-EXAMS modeling using the NY
grape scenario assuming drip lines are not buried (0.1 cm) or are buried
at 5 cm and 25 cm were used to calculate acute RQs for freshwater fish
and invertebrates (Table 15).  Based on this analysis acute risk LOCs
for freshwater fish and invertebrates are exceeded if 1,3-D is applied
above or at the ground surface but not below at the depths modeled.

Table 15.  Acute RQs for freshwater fish and invertebrates due to
exposure to 1,3-D in runoff.

Taxon (Test Species)	Irrigation Line Depth (cm)	Peak Water Concentration
(ppm)	LC50 (ppm)	RQ1

Freshwater Fish (Walleye)	0.1	0.610	1.08	0.56

	5.0	0.003

<0.01

	25.0	0.002

<0.01

Freshwater Invertebrates (Daphnia)	0.1	0.610	0.09	6.78

	5.0	0.003

0.03

	25.0	0.002

0.02

1Rounded to the nearest hundredth. Values in bold exceed the aquatic
acute LOC.

Chronic Risk to 1,3-D – Chronic risk to fish as a result of exposure
to 1,3-D in runoff could not be determined because data are unavailable.
 However, since 1,3-D is moderately toxic to freshwater fish on an acute
basis, EFED expects chronic risk to be a concern.  Submission of a valid
early life cycle test with freshwater fish will clarify this
presumption.  For freshwater invertebrates, the 21-day concentration of
1,3-D in a standard pond was used to calculate chronic RQs, consistent
with EFED policy. These values are presented for the three depths used
in the analysis of acute effects to freshwater animals (Table 16).
Based on these values, chronic risk is a concern for freshwater
invertebrates if applications are made above or at the ground surface
but not below at the depths modeled.

Table 16.  Chronic RQs for freshwater invertebrates due to exposure to
1,3-D in runoff.

Taxon

(Test Species)	Irrigation Line Depth (cm)	21-Day Conc. (ppm)	NOAEC (ppm)
RQ

(21-Day)1

Freshwater Invertebrates (Daphnia)	0.1	0.1796	0.117	1.54

	5.0	0.0007

0.01

	25.0	0.0008

0.01

1Rounded to the nearest hundredth. Values in bold meet or exceed the
chronic LOC for aquatic animals of 1.0.

Acute Risk to 3-Chloroallyl alcohol/3-Chloroacrylic acid – EECs for
the degradates of 1,3-D were estimated assuming 6.4% and 10%
transformation of the parent to the alcohol and acid degradates,
respectively (based on the aerobic aquatic metabolism study for the
parent, MRID 44975502).  These percentages were applied to the parent
EECs in Table 11.  Based on this analysis acute risk LOCs for freshwater
fish and invertebrates do not exceed any LOCs for aquatic animals (Table
17).

Table 17.  Acute RQs for freshwater fish and invertebrates due to
exposure to 1,3-D degradates in runoff.

Taxon (Test Species)	Irrigation Line Depth (cm)	Peak Water Concentration
(ppm)	LC50 (ppm)	RQ1

3-Chloroallyl Alcohol

Freshwater Fish

(Rainbow trout)	0.1	0.039	0.986	0.04

	5.0	0.0002

<0.01

	25.0	0.0001

<0.01

Freshwater Invertebrates (Daphnia)	0.1	0.039	2.3	0.02

	5.0	0.0002

<0.01

	25.0	0.0001

<0.01

3-Cloroacrylic Acid

Freshwater Fish

(Rainbow trout)	0.1	0.061	69.5	<0.01

	5.0	0.0003

<0.01

	25.0	0.0002

<0.01

Freshwater Invertebrates (Daphnia)	0.1	0.061	55.0	<0.01

	5.0	0.0003

<0.01

	25.0	0.0002

<0.01

1Rounded to the nearest hundredth.

Chronic risks to degradates cannot be determined for freshwater fish and
invertebrates due to lack of these data.  However, since they are
slightly to highly toxic to these taxa, chronic risk from the degradates
may be a concern.

	Marine/Estuarine Fish and Invertebrates

Acute Risk to 1,3-D - The same peak values from PRZM-EXAMS were used to
estimate acute risk to marine/estuarine fish and invertebrates (Table
18).  Based on this analysis acute risk LOCs for marine/estuarine fish
and invertebrates are exceeded if 1,3-D is applied above or at the
ground surface but not below at the depths modeled.

Table 18.  Acute RQs for marine/estuarine fish and invertebrates due to
exposure to 1,3-D in runoff.

Taxon (Test Species)	Irrigation Line Depth (cm)	Peak Water Concentration
(ppm)	LC50/EC50 (ppm)	RQ1

Marine/Estuarine Fish (Sheepshead minnow)	0.1	0.610	0.87	0.70

	5.0	0.003

<0.01

	25.0	0.002

<0.01

Marine/Estuarine Invertebrates (Eastern oyster)	0.1	0.610	0.64	0.95

	5.0	0.003

<0.01

	25.0	0.002

<0.01

1Rounded to the nearest hundredth. Values in bold exceed an aquatic LOC.

Chronic Risk to 1,3-D - The same approach as above was used to calculate
the chronic risk to marine/estuarine invertebrates as a result of
exposure to 1,3-D.  Chronic data were not available with which to assess
this risk; however, a NOAEC value was estimated using the ratio of acute
to chronic toxicity values calculated for freshwater invertebrates
(Table 19).  Based on these values, chronic risk is a concern for
marine/estuarine invertebrates if applications are made above or at the
ground surface.  However, applying 1,3-D below the surface of the ground
at 5 cm and 25 cm minimizes this risk.  Chronic RQs for marine/estuarine
fish could not be estimated because of lack of data.  However, since
1,3-D is highly toxic to marine/estuarine fish on an acute basis,
chronic risks are expected to be a concern.

Table 19. Chronic RQs for marine/estuarine invertebrates due to exposure
to 1,3-D in runoff.

Taxon

	Irrigation Line Depth (cm)	21-Day Conc. (ppm)	NOAEC (ppm)	RQ

(21-Day)1

Marine/Estuarine Invertebrates 	0.1	0.1796	0.02	8.98

	5.0	0.0007

0.04

	25.0	0.0008

0.04

1Rounded to the nearest hundredth. Values in bold meet or exceed the
chronic LOC for aquatic animals.

Data are not available to assess the acute or chronic risk of
3-chloroallyl alcohol or 3-chloroacrylic acid to marine/estuarine fish
or invertebrates.  However, risks to marine/estuarine species appear to
track those of freshwater species.  Therefore, acute risk may not be
likely for marine/estuarine fish or invertebrates.  Until such time as
data are submitted for the chronic toxicity of the degradates, chronic
risks for marine/estuarine species remains uncertain.

	Aquatic Plants/Algae (Freshwater and Marine/Estuarine)

Risk of Freshwater and Marine/Estuarine Aquatic Plants/Algae to 1,3-D
– Using the most sensitive species for freshwater and marine/estuarine
plants and algae, none of the non-listed or listed RQs calculated for
these taxa exceeded the LOC for aquatic plants (Table 20).

Table 20.  Acute RQs for marine/estuarine fish and invertebrates due to
exposure to 1,3-D in runoff.

Taxon (Test Species)	Irrigation Line Depth (cm)	Peak Water Conc. (ppm)
EC50 (ppm)	EC5/ NOAEC (ppm)	Non-Listed RQ1	Listed RQ1

Freshwater aquatic plants/algae

(Freshwater diatom)	0.1	0.610	7.9	EC5 = 2.7	0.08	0.23

	5.0	0.003

	<0.01	<0.01

	25.0	0.002

	<0.01	<0.01

Marine/Estuarine Aquatic plants/algae

(Saltwater diatom)	0.1	0.610	15.5	NOAEC = 8.8	0.04	0.07

	5.0	0.003

	<0.01	<0.01

	25.0	0.002

	<0.01	<0.01

1Rounded to the nearest hundredth. Values in bold exceed an aquatic
plant LOC of 1.0.

Risk of Freshwater and Marine/Estuarine Aquatic Plants/Algae to
3-Chloroallyl Alcohol/3-Chloroacrylic Acid – Using the most sensitive
species for freshwater plants and the toxicity data for marine diatom,
the LOC for listed aquatic plants is exceeded for applications that are
made to the surface and only for the 3-chloroacrylic acid degradate
(Table 21).  The LOC is not exceeded for the alcohol degradate or for
the acid degradate in cases where the irrigation line is buried at 5 cm
and 25 cm.

Table 21.  Acute RQs for marine/estuarine fish and invertebrates due to
exposure to 1,3-D degradates in runoff.

Taxon (Test Species)	Irrigation Line Depth (cm)	Peak Water Conc. (ppm)
EC50 (ppm)	EC5/ NOAEC (ppm)	Non-Listed RQ1	Listed RQ1

3-Chloroallyl Alcohol

Freshwater aquatic plants/algae

(Duckweed)	0.1	0.039	1.694	NOAEC = 0.042	0.02	0.932

	5.0	0.0002

	<0.01	<0.01

	25.0	0.0001

	<0.01	<0.01

Marine/Estuarine Aquatic plants/algae

(Saltwater diatom)3	0.1	0.039	0.248	NOAEC = 0.071	0.15	0.55

	5.0	0.0002

	<0.01	<0.01

	25.0	0.0001

	<0.01	<0.01

3-Chloroacrylic Acid

Freshwater aquatic plants/algae

(Duckweed)	0.1	0.061	0.22	EC05 = 0.0023	0.28	26.52

	5.0	0.0003

	<0.01	0.13

	25.0	0.0002

	<0.01	0.08

Marine/Estuarine Aquatic plants/algae

(Saltwater diatom)	0.1	0.061	50.2	NOAEC = 23.7	<0.01	<0.01

	5.0	0.0003

	<0.01	<0.01

	25.0	0.0002

	<0.01	<0.01

1Rounded to the nearest hundredth. Value in bold exceeds aquatic plant
LOC of 1.0.

2This value approaches the LOC for listed aquatic species.  Since there
are risks shown for aquatic plants due to exposure to 3-chloroallyl
alcohol, a conservative conclusion is that this value equals an
exceedance.  Drip irrigation lines that are buried would minimize this
risk.

Risk Description

	Terrestrial Animals

Conclusions for risks for birds and mammals are described below.
Conclusions for birds are also extended to reptiles and terrestrial
phase amphibians, as their sensitivity is assumed to approximate that of
birds.  The analyses below are based on an estimated concentration of
1,3-D in soil assuming a 505 vines/acre, a circular treated area under
each vine that is two feet in diameter, and a 9-inch wetting depth.
This results in a higher estimated concentration in the soil at the
treated locations than the value used in previous risk assessments.
However, this value represents the worst-case scenario of a bird or
mammal foraging only at treated locations under vines.  The actual area
treated in this scenario is only 3.64% of an acre, which reduces the
chance of encountering 1,3-D within the treated grape vineyard
substantially.  This analysis also assumes that this concentration is
present at the soil surface, and no attempt has been made to determine
the difference in effects resulting from application in drip lines that
are above ground or buried.  However, application through buried drip
lines is expected to reduce risk to terrestrial animals further.

Calculations of acute and chronic RQs for terrestrial animals as a
result of exposure to 1,3-D via drip irrigation were updated for
consistency with current EFED policy concerning dietary risks to
terrestrial animals.  This approach uses the maximum estimate of
incidental soil ingestion and estimates of dietary ingestion as a
percentage of body weight based on equations utilized in EFED’s T-REX
risk assessment model.  This model also adjusts the LD50 for standard
avian and mammalian body weights assuming a default scaling factor for
birds and mammals, which yields a more conservative estimate of RQs
compared to previous risk assessments.

Previous risk assessments identified exposure through drinking water as
a potential source of risk.  The proposed label prohibits formation of
puddles of irrigation water during treatment, and requires the
applicator to cease treatment if this occurs.  Therefore, irrigation
water is not expected to be a significant source of exposure to
terrestrial animals.  This does not preclude risk from exposure to 1,3-D
and its degradates in on-field puddles.  EFED is currently developing a
model to address this exposure, and it should be examined in future for
this pesticide.

	Birds

Based on the analysis, RQs for birds did not exceed any LOCs using the
estimated soil concentration of 170.2 ppm in soil, assuming that birds
consume the maximum percentage of soil in the diet as determined by
Beyer et al. (1994).  The analysis also assumes that only 3.64% of the
soil consumed contains 1,3-D, since that value represents the percentage
of area of an acre of grape vineyard that is actually treated with
1,3-D.  Therefore, EFED concludes that acute risk to birds from
incidental ingestion of soil containing 1,3-D is minimal.

The acute inhalation risk to birds cannot be determined due to lack of
inhalation data for birds.  However, since acute inhalation risk to
mammals was not found, EFED expects acute inhalation risk to birds to be
low.

Chronic risks for birds were dismissed in the 1999 Section 18 risk
assessment for grapes in California, but no explanation was provided.
Chronic risks to birds cannot be addressed here due to lack of chronic
data with 1,3-D and its degradates.  Based on the analysis for mammals,
chronic risk was not determined to be a concern for the proposed use
(see below).  Since birds are apparently more sensitive than mammals on
an acute oral basis, chronic risks to birds may be higher, but whether
this would lead to significant risk is unknown.

Data are not available to determine the acute or chronic risks to birds
as a result of exposure to 3-chloroallyl alcohol and 3-chloroacrylic
acid.  However, since at least one of the degradates is more toxic than
1,3-D in many taxa, this relationship may be true for birds as well.
Therefore, acute avian toxicity data should be submitted for
3-chloroallyl alcohol and 3-chloroacrylic acid.  Chronic risk cannot be
determined for birds either as a result of exposure to the degradates.
Since chronic exposure is likely to be low due to the relatively small
treated area within a grape crop, EFED is not requesting avian chronic
data with 3-chloroallyl alcohol and 3-chloroacrylic acid at this time.

	Mammals

Acute risk to mammals as a result of ingestion of treated soil and
inhalation of 1,3-D vapors was found to be minimal.

Chronic risks were dismissed for mammals in the Section 18 risk
assessment for grapes, but no support was provided for this conclusion.
Foraging in the treated areas 100% of the time is unlikely for mammals,
unless they are attracted to those areas for some reason.  If random
foraging is assumed, chronic RQs are below the LOC for all body size
classes based on the estimated treated area used in our analysis.  This
area would be greater if more vines were planted per acre; however, the
maximum application rate on a per acre basis would not change, so the
estimated soil concentration would decrease.  As a result of the low
probability of encounter, EFED concludes that the chronic risk to
mammals based on the proposed use is likely minimal.  Further monitoring
information would help to refine the estimate of risk, and until such
data are provided the EECs used are considered to be sufficient.

Acute risk to mammals due to ingestion of degradates within the soil was
found to be minimal.  Chronic data are not available with which to
assess the risks to mammals, but since the degradates appear to be more
toxic than the parent compound, the degradates may have the potential to
cause chronic effects in mammals.  However, based on the scenario
described above, exposure may limit this potential for risk in the
proposed use.

	Terrestrial Plants

The proposed use of 1,3-D results in risk to listed and non-listed
dicotyledonous plants inhabiting semi-aquatic areas as a result of
residues contained in runoff.  These risks were identified for
applications made at or above ground level, but not applications made
through drip lines buried 5 cm and 25 cm.  Therefore, applications made
through drip lines buried at least 5 cm will minimize risk of 1,3-D to
non-target plants.

Risk of exposure to 3-chloroallyl alcohol and 3-chloroacrylic acid for
plants in terrestrial and semi-aquatic areas also cannot be determined
yet because the methods used in plant toxicity studies are in question.
However, the issues raised with these studies are expected to be
resolved soon, and EFED will communicate its findings as to the status
of these studies and risk to plants as soon as they are available.

 	Aquatic Animals

Conclusions for freshwater and marine/estuarine fish and invertebrates
are described below.  Results for fish are also extended to
aquatic-phase amphibians, since EFED assumes that fish approximate the
sensitivity of amphibians to pesticides.

	Freshwater Fish

Acute RQs were exceeded for freshwater fish as a result of the proposed
1,3-D applications made at or above the ground surface.  At- or
above-ground applications, therefore, will result in runoff that
contains enough 1,3-D to cause mortality to listed and non-listed
freshwater fish.  The incident described above involving multiple
species of fish demonstrates the toxicity of this compound to fish.
Although this incident resulted from accidental misuse, they support the
concerns for aquatic species.  Modeling results demonstrated that RQs
were well below the acute LOCs for fish when the proposed application of
1,3-D is made below the surface.  Our results demonstrate minimal acute
risk at a depth of 5 cm; the effects resulting from burial at <5 cm are
uncertain, but would likely offer protection to fish compared to at- or
above-ground applications.

Chronic risks to freshwater fish could not be determined.  However,
since 1,3-D is moderately toxic to freshwater fish on an acute basis,
EFED cannot preclude the potential for chronic risk to this taxon as a
result of exposure in runoff.  Until such time as data are submitted to
determine these risks, they will remain uncertain.  However, EFED also
expects that applications made through buried drip irrigation lines
would reduce the potential for chronic risk to this taxon.

Acute RQs calculated for freshwater fish as a result of exposure to
3-chloroallyl alcohol and 3-chloroacrylic acid did not exceed any fish
LOCs at any of the depths modeled.  Therefore, mortality is not expected
as a result of exposure from runoff due to the proposed use.  Chronic
data are not available for this taxon, so the potential for chronic risk
remains an uncertainty.

	Freshwater Invertebrates

Acute and chronic RQs were exceeded for freshwater invertebrates as a
result of the proposed 1,3-D applications made at or above the ground
surface.  At- or above-ground applications will result in runoff that
contains enough 1,3-D to cause mortality and chronic/reproductive
effects to listed and non-listed freshwater invertebrates.  As described
for freshwater fish above, application through buried irrigation lines
will reduce these risks.

Acute RQs calculated for freshwater invertebrates as a result of
exposure to 3-chloroallyl alcohol and 3-chloroacrylic acid did not
exceed any fish LOCs at any of the depths modeled.  Therefore, mortality
is not expected as a result of exposure from runoff due to the proposed
use.  Chronic data are not available for this taxon, so the potential
for chronic risk remains an uncertainty.

	Marine/Estuarine Fish

Acute risk is expected for listed and non-listed marine/estuarine fish
as a result of exposure of 1,3-D in runoff due to the proposed use.  As
with freshwater fish, these risks are expected to be minimized if
irrigation lines are buried.  Chronic RQs could not be determined due to
lack of data for this taxon.  Acute to chronic ratios could not be
calculated either, since the chronic toxicity study of 1,3-D on
freshwater fish was found to be invalid.  Since 1,3-D is highly toxic to
marine/estuarine fish on an acute basis, chronic risks are expected for
this taxon.

Acute and chronic data are not available to estimate the risks of
3-chloroallyl alcohol and 3-chloroacrylic acid to marine/estuarine fish.
 This remains an uncertainty; however since acute risks were not
identified for freshwater fish as a result of exposure to 3-chloroallyl
alcohol and 3-chloroacrylic acid, concern for marine/estuarine fish
acute risk may be low as well.  Chronic risk remains unknown; however,
exposure to the degradates is expected to be less than that of 1,3-D,
and any chronic risk to 3-chloroallyl alcohol and 3-chloroacrylic acid
is expected to be reduced through application of 1,3-D through buried
drip lines.

	Marine/Estuarine Invertebrates

Acute risk is expected for listed and non-listed marine/estuarine
invertebrates as a result of exposure of 1,3-D in runoff due to the
proposed use.  As with other aquatic taxa described above, these risks
are expected to be minimized if irrigation lines are buried.  Chronic
RQs were also exceeded for this taxon, based on a NOAEC estimated using
acute-to-chronic toxicity ratios for freshwater invertebrates.  Based on
the analysis with the estimated NOAEC value, these findings were similar
to that of other aquatic taxa in which risks are expected to be
minimized if irrigation lines are buried below the soil surface.

Acute and chronic data are not available to estimate the risks of
3-chloroallyl alcohol and 3-chloroacrylic acid to marine/estuarine
invertebrates.  This remains an uncertainty; however since acute risks
were not identified for freshwater invertebrates, concern for
marine/estuarine invertebrate acute risk may be low as well.  Chronic
risk is presumed to be likely based on chronic risks identified for
1,3-D and increased toxicity of 3-chloroallyl alcohol. However, exposure
to the degradates is expected to be less than that of 1,3-D, and any
chronic risk would be reduced through application of 1,3-D through
buried drip lines.

	Aquatic Plants/Algae

A thorough set of data is available with which to determine the risks of
aquatic plants and algae to 1,3-D as well as its degradates (except
marine diatoms).  However, many of the studies for the degradates are
considered supplemental because the test substance purity was not
reported or known.  This does present some uncertainty in the results of
those studies.

Risks to listed and non-listed freshwater and marine/estuarine aquatic
plants and algae from exposure to 1,3-D in runoff were minimal.
However, risk was identified for listed freshwater aquatic plants as a
result of exposure to the degradates 3-chloroallyl alcohol and
3-chloroacrylic acid.  The RQ exceeded the LOC of 1.0 for the acid
degradate, and was 0.93 for the alcohol degradate.  Although 0.93 does
not technically exceed the LOC, it may still indicate potential harm to
listed species.  The degradates are expected to be simultaneously
present, so this does not change any risk conclusions.  Similar to risks
to other aquatic taxa, these risks would be minimized by applying 1,3-D
in buried irrigation lines.

Endocrine Disruption

EPA is required under the FFDCA, as amended by FQPA, to develop a
screening program to determine whether certain substances (including all
pesticide active and other ingredients) "may have an effect in humans
that is similar to an effect produced by a naturally occurring estrogen,
or other such endocrine effects as the Administrator may designate."
Following the recommendations of its Endocrine Disruptor Screening and
Testing Advisory Committee (EDSTAC), EPA determined that there was a
scientific basis for including, as part of the program, the androgen and
thyroid hormone systems, in addition to the estrogen hormone system.
EPA also adopted EDSTAC’s recommendation that the Program include
evaluations of potential effects in wildlife.  For pesticides, EPA will
use FIFRA authority and, to the extent that effects in wildlife may help
determine whether a substance may have an effect in humans, FFDCA
authority to require wildlife evaluations.  As the science develops and
resources allow, screening of additional hormone systems may be added to
the Endocrine Disruptor Screening Program (EDSP).  When the appropriate
screening and/or testing protocols being considered under the Agency’s
EDSP have been developed, 1,3-D and its degradates, 3-chloroallyl
alcohol and 3-chloroacrylic acid, may be subjected to additional
screening and/or testing to better characterize effects related to
endocrine disruption.

V.	Federally Listed-Species Concerns tc \l3 "Federally Listed-Species
Concerns

		A.	Action Area

The action area is considered to be the area in which listed species may
be affected directly or indirectly by the Federal action.  The action
area may extend beyond the immediate treatment area due to transport of
the pesticide by pathways such as runoff, drift, or movement of exposed
animals.

For 1,3-D, the action area includes the treatment site as well as sites
to which it is transported via environmental processes.  1,3-D is
expected to move offsite through wind movement of volatilized active
ingredient or through runoff.  Because it is more dense than air,
volatilized 1,3-D will move along the ground and can be deposited onto
nearby areas, contacting soil, plants, and water bodies.  The distance
to which it moves in this manner is dependent on wind speed and
landscape features nearby (e.g., hedgerows, windbreaks, forest) that may
intercept the volatilized chemical.  Runoff of 1,3-D is also expected to
occur, which could result in contact with adjacent areas and nearby
water bodies. Leaching could also result in transport in this manner.
If 1,3-D reaches moving surface water, it could be transported to other
surface water bodies including streams and rivers, ponds, lakes,
estuaries, and coastal areas, depending on its proximity to these waters
and the rate of dissipation of 1,3-D in water.  The EPISuite program
v3.12 estimates a volatilization half-life of 3.3 hours for a river 1
meter deep with a flow velocity of 1 meter/second and a wind velocity of
3 meters/second.  For a lake 1 meter deep, with a flow rate of 0.05
meters/second and a wind speed of 0.5 meters/second, the volatilization
half-life is expected to be 102 hours.  1,3-D would contact aquatic
plants and animals in the water, but would also reach riparian areas.
In addition, these waters likely serve as drinking water sources for
terrestrial animals.

The potential for secondary toxicity is unknown, but cannot be precluded
without further data.  However, 1,3-D is not expected to bioaccumulate
and will not likely cause effects far up any food chain.

The degradates of 1,3-D would also need consideration for a listed
species risk assessment, since at least one of them (mainly the alcohol
degradate) is more toxic to several taxa than the parent.  These
compounds are not highly volatile, but they are expected to form where
1,3-D is applied or transported and also to be transported via water
movement.

		B.	Taxonomic Groups Potentially at Risk

The screening-level assessment for listed species uses the
listed-species LOCs to identify concerns for adverse effects to listed
species.  For those taxa or measurement endpoints for which guideline
studies are not available, EFED uses any relevant data from the
literature to make a qualitative assessment of potential exposures
pathways and risks.  Taxa identified as being at potential direct risk
from the proposed use of 1,3-D to grapes include the following:

Dicotyledonous plants inhabiting semi-aquatic areas

Freshwater fish, acute (reproductive/chronic uncertain)

Freshwater invertebrates, acute and reproductive/chronic

Freshwater plants and algae

Amphibians, acute (reproductive/chronic uncertain)

Marine/estuarine fish, acute (reproductive/chronic uncertain)

Marine/estuarine invertebrates, acute and reproductive/chronic

It must be reiterated here that the risks for the above taxa are based
on EECs derived with the assumption that 1,3-D will be applied at or
above the surface as allowed on the proposed label.  RQs are below the
listed species LOCs for aquatic animals and plants/algae if applications
are made below the soil surface, so these applications do not present
risk to listed aquatic species.

Although risk was identified only for dicotyledonous species of plants
inhabiting semi-aquatic areas, the correlation of these risks to
non-flowering species is unknown.  Therefore, although direct risk to
monocotyledonous species in terrestrial and semi-aquatic areas can be
ruled out based on our analysis, non-flowering plants cannot and are
thus included in the list of species in Appendix III.

C.	Probit Dose Response Relationship

An analysis has been conducted of the probability of individual
mortality at the listed-species LOC (0.05 for aquatic organisms) as well
as at the predicted acute exposure level (RQ) for aquatic animals
demonstrating acute risk to 1,3-D.  The analysis is based on a
spreadsheet IECv1.1.xls developed by EFED in 2004.  The individual
effects probability associated with the LOCs is based on the mean
estimate of the slope and an assumption of a probit dose- response
relationship.  In addition to a single effects probability estimate
based on the mean, upper and lower estimates of the effects probability
are also provided to account for variance in the slope.  The upper and
lower bounds of the effects probability are based on available
information on the 95% confidence interval of the slope.  Since the
slope could not be determined or is not known from the aquatic studies
used in this risk assessment, a default value of 4.5 was used.  Acute
risk was not demonstrated in terrestrial animals, so they are excluded
from this analysis.  Acute risk was also not demonstrated in any animal
taxa as a result of exposure to the degradates of 1,3-D, so these RQs
are not used in this analysis.

The probability of an individual fish or invertebrate animal mortality
at the LOC of 0.05 is 1 in 4.18 x 108 (<<0.01%).  EFED recognizes that
extrapolation of very low probability events is associated with
considerable uncertainty in the resulting estimates.  Using the actual
RQs calculated for each animal taxon listed in the section above, the
chance of individual mortality is 13% for freshwater fish (RQ = 0.56;
this also applies to amphibians), 100% for freshwater invertebrates (RQ
= 6.78), 24% for marine/estuarine fish (RQ = 0.7), and 46% for
marine/estuarine invertebrates (RQ = 0.95).

D.	Indirect Effects Analysis

The Agency acknowledges that pesticides have the potential to exert
indirect effects upon listed organisms; for example, by perturbing
forage or prey availability or altering the extent and nature of nesting
habitat.  In conducting a screen for indirect effects, the Agency uses
the direct effects LOCs for each taxonomic group to make inferences
concerning the potential for indirect effects upon listed species that
rely upon non-endangered organisms in these taxonomic groups as
resources critical to their life cycle.  For 1,3-D and/or its
degradates, direct-effect LOCs are exceeded for dicotyledonous plants,
non-flowering plants, freshwater fish (and amphibians), freshwater
invertebrates, marine/estuarine fish, and marine/estuarine
invertebrates.  Thus, there may be a potential for indirect effects to
listed species that are dependent upon these plants and animals and,
where applicable, their seeds or eggs as a food source.  Direct effect
LOCs are also exceeded for listed freshwater aquatic plants.  Therefore,
any specialist organism requiring listed aquatic plants for food or
habitat is at risk for indirect effects. Direct and indirect effects to
listed species are characterized for each taxon in Table 22, and these
taxa were included in the list of threatened and endangered species
co-occurring in counties in which grapes are grown in Appendix III.

Table 22. Expected direct and indirect effects to listed species.

Listed Taxon	Direct Effects	Indirect Effects

Terrestrial and semi-aquatic plants - monocots	No	Yes1

Terrestrial and semi-aquatic plants - dicots	Yes	Yes1

Terrestrial invertebrates	No	Yes1,2

Birds	No	Yes1,2,3,4,5,6,7

Terrestrial-phase amphibians	No	Yes1,2,5

Reptiles	No	Yes1,2,3,4,5,6,7

Mammals	No	Yes1,2,3,4,5,6,7

 Aquatic non-vascular plants	Yes	Yes1,2

Aquatic vascular plants	Yes	Yes1,2

Freshwater fish	Yes (Acute)	Yes1,2,3,4,5

Aquatic-phase amphibians	Yes (Acute)	Yes1,2,4,5

Freshwater crustaceans	Yes (Acute and Chronic)	Yes1,2,5

Mollusks	Yes (Acute and Chronic)	Yes1,2,5

Marine/estuarine fish	Yes (Acute)	Yes1,2,6,7

Marine/estuarine crustaceans	Yes (Acute and Chronic)	Yes1,2,6,7

1Indirect effects are possible if direct effects occur to listed or
non-listed dicots and non-flowering plants in semi-aquatic areas. For
aquatic species, this may include indirect effect due to loss of
riparian plants.

2Direct effects are expected for listed aquatic plants. Indirect effects
could occur to specialists on these species.

3Direct effects are expected for freshwater fish

4Direct effects are expected for aquatic-phase amphibians

5Direct effects are expected for freshwater crustaceans and mollusks

6Direct effects are expected for marine/estuarine fish

7Direct effects are expected for marine/estuarine crustaceans and
mollusks

E.	Critical Habitat

In the evaluation of pesticide effects, consideration is given to the
physical and biological features (constituent elements) of critical
habitats.  Critical habitat is designated by the USFWS and NMFS as
essential to the conservation of a listed species and which may require
special management considerations or protection.  The evaluation of
impacts for a screening-level risk assessment focuses on the biological
features that are constituent elements and is accomplished using the
screening-level taxonomic analysis (RQs and LOCs) used to evaluate
direct and indirect effects to listed organisms.

The screening-level risk assessment has identified potential concerns
for indirect effects on listed species for those organisms dependant
upon listed and non-listed mammals, amphibians, freshwater fish and
invertebrates, marine/estuarine fish and invertebrates, and listed
freshwater plants.  In light of the potential for indirect effects, the
next step for EPA and the Service(s) is to identify which listed species
and critical habitat are potentially implicated.  Analytically, the
identification of such species and critical habitat can occur in either
of two ways.  First, the agencies could determine whether the action
area overlaps critical habitat or the occupied range of any listed
species.  If so, EPA would examine whether the pesticide's potential
impacts on non-endangered species would affect the listed species
indirectly or directly affect a constituent element of the critical
habitat.  Alternatively, the agencies could determine which listed
species depend on biological resources, or have constituent elements
that fall into, the taxa that may be directly or indirectly impacted by
the pesticide.  Then EPA would determine whether use of the pesticide
overlaps the critical habitat or the occupied range of those listed
species.  At present, the information reviewed by EPA does not permit
use of either analytical approach to make a definitive identification of
species that are potentially impacted indirectly or critical habitats
that is potentially impacted directly by the use of the pesticide.  EPA
and the Service(s) are working together to conduct the necessary
analysis.

This screening-level risk assessment for critical habitat provides a
listing of potential biological features that, if they are constituent
elements of one or more critical habitats, would be of potential
concern.  These correspond to the taxa identified above as being of
potential concern for indirect effects.  This list should serve as an
initial step in problem formulation for further assessment of critical
habitat impacts outlined above, should additional work be necessary.

F.	Co-occurrence Analysis

The goal of the co-location evaluation is to determine whether potential
use sites containing grapes are geographically associated with known
locations of listed species that might be exposed.  At the screening
level, this analysis is typically done using EFED’s LOCATES database,
which contains state and county-level data for listed species.  Appendix
III provides a synopsis of listed species by State and taxa (terrestrial
plants, freshwater fish and invertebrates, amphibians, marine/estuarine
fish and invertebrates, and aquatic plants).

Based on our conclusions of aquatic risks due to runoff at the depths
modeled, provisions on the proposed label that require application
through buried irrigation lines would reduce aquatic risks.  Therefore,
aquatic plant and animal species and terrestrial plant species included
in Appendix III could be removed if this provision was included.  The
effects due to runoff from 1,3-D applied at different depths were not
explored, so the actual depth that would provide this protection would
have to be identified.

		VI.	Assumptions and Uncertainties

The label allows for applications above, at, or below the ground
surface.  Our analyses utilized 5cm and 25cm depth for buried irrigation
lines, but actual depths are unknown.  Effects are clearly different
between 0.1cm depth and 5cm depth, and the actual depth that reduces RQs
below the LOC is unknown.

Surrogate species are assumed to adequately represent the sensitivity
and exposure of non-target species exposed in the field.  The extent to
which this is true is not known.

Estimates of 1,3-D concentration in the soil were determined based on
assumed values of row spacing, vine spacing, and treated area and depth
of soil beneath each vine.  This measurement is assumed to be a
reasonable exposure estimate, but the actual soil concentration
resulting from the proposed will vary with the configuration of vines
within a vineyard.  However, the maximum application rate does not
change, so greater numbers of vines and treated area per acre will
result in a greater chance for encountering treated soil, but a lower
concentration in soil beneath each vine.  Our estimate is assumed to be
conservative.

Plant risk as a result of exposure to the degradates of 1,3-D
(3-chloroallyl alcohol and 3-chloroacrylic acid) cannot yet be
quantified, since the status of the plant toxicity studies with these
chemicals is pending.  Until these data are determined to be useful,
risk due to these chemicals remain uncertain.

Chronic NOAEC values for marine/estuarine invertebrates were derived
from calculations of the acute-to-chronic toxicity ratios for freshwater
species.  The actual ratio in marine/estuarine species commonly tested
is not known.  However, since effects in marine/estuarine species appear
to be consistent with those of freshwater species, this value may be a
sufficient estimate.

Appendix I.  PRZM-EXAMS results

New York Grapes, 0.1 cm incorporation

stored as NYgrapes1mm.out

Chemical: telone

PRZM environment: NYGrapesC.txt	modified Friday, 8 August 2003 at
07:42:08

EXAMS environment: pond298.exv	modified Thuday, 29 August 2002 at
15:33:30

Metfile: w14860.dvf	modified Wedday, 3 July 2002 at 08:06:14

Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 day	90 day	Yearly

1961	137	92.16	31.05	12.28	8.497	2.18

1962	66.92	47.18	20.63	9.229	6.527	2.097

1963	20.37	13.96	4.802	2.694	1.982	0.8638

1964	12.93	8.778	2.936	1.046	1.26	0.3618

1965	276	176	55.69	21.66	16.67	4.17

1966	60.09	38.27	11.92	4.934	3.325	1.222

1967	186	128	45.55	17.84	21.04	5.267

1968	23.81	15.79	8.345	3.164	2.533	1.091

1969	108	74.21	25.29	9.77	7.15	2.04

1970	61.3	44.37	20.78	11.45	9.74	3.291

1971	47.64	33.27	11.94	4.76	3.558	1.501

1972	31.39	21.94	8.034	4.46	3.707	1.067

1973	127	86.61	29.04	10.53	8.609	2.173

1974	287	200	73.18	28.67	20.7	5.7

1975	627	489	185	72.28	50.5	15.12

1976	92.05	64.06	23	11.22	7.688	2.947

1977	452	309	105	39.84	28.87	7.979

1978	213	148	52.74	23.05	19.68	6.79

1979	251	170	66.75	26.22	17.72	5.924

1980	458	364	131	50.32	34.54	9.038

1981	115	79.96	28.34	10.92	8.051	3.591

1982	84.68	60.52	24.74	10.67	12.43	3.742

1983	101	71.54	26.62	12.37	9.276	2.581

1984	113	78.91	29.7	10.64	7.484	1.952

1985	277	190	104	38.91	27.13	6.88

1986	33.45	22.36	12.21	10.68	7.775	2.64

1987	272	204	72.85	27.35	19.4	4.847

1988	1020	704	243	89.47	68.76	18.26

1989	130	87.21	28.51	13.87	11.24	3.683

1990	863	594	216	81.14	55.23	13.76

0.1			610.1		476.5			179.6			70.084	48.904		13.2878

					Average of yearly averages:	4.75862

Inputs generated by pe4.pl - 8-August-2003

Data used for this run:

Output File: NYgrapes1mm

Metfile:	w14860.dvf

PRZM scenario:	NYGrapesC.txt

EXAMS environment file:	pond298.exv

Chemical Name:	telone

Description	Variable Name	Value	Units	Comments

Molecular weight	mwt	110.97	g/mol

Henry's Law Const.	henry	3.55e-3	atm-m^3/mol

Vapor Pressure	vapr	34	torr

Solubility	sol	2500	mg/L

Kd	Kd		mg/L

Koc	Koc	41	mg/L

Photolysis half-life	kdp	0	days	Half-life

Aerobic Aquatic Metabolism	kbacw	195.2	days	Halfife

Anaerobic Aquatic Metabolism	kbacs	60	days	Halfife

Aerobic Soil Metabolism	asm	97.6	days	Halfife

Hydrolysis:	pH 5	0	days	Half-life

Hydrolysis:	pH 7	0	days	Half-life

Hydrolysis:	pH 9	0	days	Half-life

Method:	CAM	4	integer	See PRZM manual

Incorporation Depth:	DEPI	0.1	cm

Application Rate:	TAPP	19.8	kg/ha

Application Efficiency:	APPEFF	1.0	fraction

Spray Drift	DRFT	0	fraction of application rate applied to pond

Application Date	Date	15-08	dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1	interval	60	days	Set to 0 or delete line for single app.

Record 17:	FILTRA

	IPSCND	1

	UPTKF	0

Record 18:	PLVKRT	0

	PLDKRT	0

	FEXTRC	0.5

Flag for Index Res. Run	IR	Pond

Flag for runoff calc.	RUNOFF	none	none, monthly or total(average of
entire run)

New York Grapes, 5 cm incorporation

stored as NYgrapes5cm.out

Chemical: telone

PRZM environment: NYGrapesC.txt	modified Friday, 8 August 2003 at
07:42:08

EXAMS environment: pond298.exv	modified Thuday, 29 August 2002 at
15:33:30

Metfile: w14860.dvf	modified Wedday, 3 July 2002 at 08:06:14

Water segment concentrations (ppb)

Year	Peak	96 hr	21 day	60 day	90 Day	Yearly

1961	0.03885	0.02602	0.008715	0.003481	0.002446	0.0006425

1962	0.3277	0.2301	0.08909	0.03466	0.02454	0.006304

1963	0.02752	0.01874	0.006448	0.006384	0.004656	0.001601

1964	0.02187	0.01485	0.005444	0.002026	0.001359	0.0004673

1965	0.2192	0.14	0.04297	0.01619	0.01136	0.003129