EPA BIOPESTICIDES AND POLLUTION PREVENTION DIVISION COMPANY NOTICE OF FILING FOR PESTICIDE PETITIONS PUBLISHED IN THE FEDERAL REGISTER

EPA Biopesticides and Pollution Prevention Division contact: [Denise Greenway;<PHONE_NUMBER>]

INSTRUCTIONS:  Please utilize this outline in preparing the pesticide petition.  In cases where the outline element does not apply, please insert "NA-Remove" and maintain the outline. Please do not change the margins, font, or format in your pesticide petition. Simply replace the instructions that appear in green, i.e., "[insert company name]," with the information specific to your action.

SUBMISSION: E-mail the completed template to<EMAIL_ADDRESS> TEMPLATE:

[Becker Underwood, Inc.]

[8F7368]

	EPA has received a pesticide petition ([8F7368]) from [Becker Underwood, Inc.], [PO Box 667, Ames, IA 50010] proposing, pursuant to section 408(d) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 180 to establish an amendment/expansion of an existing tolerance exemption for the microbial pesticide  [Bacillus subtilis MBI 600]

		Pursuant to section 408(d)(2)(A)(i) of  FFDCA, as amended, [Becker Underwood, Inc.] has submitted the following summary of information, data, and arguments in support of their pesticide petition. This summary was prepared by [Becker Underwood, Inc.] and EPA has not fully evaluated the merits of the pesticide petition. The summary may have been edited by EPA if the terminology used was unclear, the summary contained extraneous material, or the summary unintentionally made the reader conclude that the findings reflected EPA's position and not the position of the petitioner.

I. [Becker Underwood, Inc.]  Petition Summary        	[8F7368]

A. Product Name and Proposed Use Practices

	[Bacillus subtilis is a naturally occurring soil saprophyte that is found in soils worldwide.  Strains of this organism are generally not regarded as human or animal pathogens.  Bacillus subtilis MBI 600 was first isolated from plots of field beans in Nottingham, UK, and this strain was subsequently researched, developed,  and commercialized by Gustafson, LLC (first registered as EPIC Biological Fungicide in 1994). The registration transferred to MicroBio in 1998 and transferred again to Becker Underwood following their acquisition of MicroBio in 2000. Becker Underwood maintains registrations for use of this strain as a seed and in-furrow treatment of agricultural commodities, and has established a tolerance exemption specific for those uses (40 CFR 180.1128).  Bacillus subtilis MBI 600 colonizes developing root and shoot systems of plants, suppressing by competition, disease organisms such as Botrytis, Fusarium, Rhizoctonia, and Alternaria as well as those organisms causing powdery mildew and anthracnose. As a result of this biological protection, vigorous root and shoot systems are established by treated plants, which often results in more uniform stands and greater yields. In addition, Bacillus subtilis MBI 600 has been shown to increase the amount of nodulation by nitrogen-fixing bacteria when applied as a seed treatment on many legumes. This improvement in nodulation is a result of a healthier root system allowing more sites for nodules to form from inoculated or naturally occurring soil borne nitrogen-fixing bacteria.

Bacillus subtilis MBI 600 is the active ingredient in Becker Underwood's INTEGRAL(R) Liquid and SUBTILEX(R) (dry) Biological Fungicide products. The products can be incorporated into growing media used in contained environments (e.g. greenhouses); or applied to agricultural crops on pre-planted seeds or by in-furrow irrigation.        The purpose of this petition is to expand the scope of the existing exemption from the requirement of a tolerance Bacillus subtilis MBI 600 from:         	"...in and on all raw agricultural commodities when applied as a seed treatment on seeds used to grow agricultural crops in accordance with good agricultural practices." 40 CFR 180.1128                to:                 "...use in and on all food commodities when applied/used in accordance with label directions."]

B. Product Identity/Chemistry

	1. Identity of the pesticide and corresponding residues. [Bacillus subtilis MBI 600.]

	2. Magnitude of residues at the time of harvest and method used to determine the residue. [Not applicable.]

	3. A statement of why an analytical method of detecting and measuring the levels of the pesticide residue are not needed. [An analytical method for residues of Bacillus subtilis MBI 600 is not necessary as this petition requests an exemption from the requirement of a tolerance without numerical limitations.]

C. Mammalian Toxicological Profile

	[Toxicological data on the active ingredient were previously accepted by the EPA to support the current exemption from the requirement of a tolerance for residues of Bacillus subtilis MBI 600 when applied as a seed treatment on agricultural commodities, as well as the various registrations originally held by Gustafson LLC, and now held by Becker Underwood. The exemption met the FQPA 1996 safety standard as presented in the Agency's Tolerance Reassessment Decision dated July 18, 2002. The acute oral toxicity study demonstrated Bacillus subtilis MBI 600 was not pathogenic, infective or toxic in rats when orally does with 2 x 10[8] CFU per animal (Toxicity Category IV). The acute dermal toxicity study found Bacillus subtilis MBI 600 was not toxic for rabbits when a single 5 x 10[10] CFU/animal (2 ml/kg body weight) dose was administered dermally to rabbits (Toxicity Category IV). An acute pulmonary toxicity/pathogenicity study found Bacillus subtilis MBI 600 to be neither toxic, pathogenic, nor infective to rats dosed intratracheally with 3.4 x 10[8] CFU of the test material (Toxicity Category IV). The acute intravenous toxicity/pathogenicity found Bacillus subtilis MBI 600 was not infective, pathogenic or toxic for rats dosed intravenously with approximately 4 x 10[7] CFU of the test material. The primary eye irritation study produced slight irritation when a single 0.1 g ocular dose was administered to rabbits. Ocular irritation dissipated 4 days post dosing (Toxicity Category IV). Finally, a hypersensitivity study noted an overall moderate skin sensitization reaction in guinea pigs 24 to 72 hours after treatment with Bacillus subtilis MBI 600. No irritation was observed in guinea pigs in a second hypersensitivity study conducted with SUBTILEX(R) Biological Fungicide. The product did not elicit a sensitizing reaction in guinea pigs and did not appear to be a dermal sensitizer.  In conclusion, Bacillus subtilis MBI 600 is not toxic to test animals when administered via the oral, dermal, intravenous or pulmonary routes of exposure.  Nor is it infective or pathogenic to test animals when administered via the oral, pulmonary and intravenous routes. Furthermore, no reports of hypersensitivity have been recorded from personnel working with this organism. Because of the lack of toxicity, pathogenicity, and infectivity, the EPA concluded the product should not pose a risk to wild mammalian species.  MBI 600 does not produce recognized toxins, enzymes, or virulence factors normally associated with mammalian invasiveness or toxicity. Non-dietary exposures would not be expected to pose any quantifiable risk due to a lack of residues of toxicological concern. In summary, the risk to human health or the environment from Bacillus subtilis MBI 600 is minimal to none.]

D. Aggregate Exposure

	1. Dietary exposure. []

	i. Food. [The proposed use pattern may result in dietary exposure with possible residues in or on agricultural commodities. However, little to no risk is expected  for the general population, including infants and children, or animals because of the lack of demonstrated toxicity/pathogenicity of Bacillus subtilis MBI 600. Furthermore, Bacillus subtilis is used in the production of fermented foods and commonly consumed by humans with no adverse health effects. Additionally, Bacillus subtilis is commonly used on a large, industrial scale basis to produce food grade products. 	Acute dietary assessments were conducted on October 10, 1993 in a Science Advisory Board (SAB) review for the registration of a Bacillus subtilis MBI 600 concentrate product. No toxicological end points of concern were identified. There are no dietary risks that exceed the Agency's Level of Concern (LOC).]

      	ii. Drinking water. [The potential for transfer of Bacillus subtilis MBI 600 to surface or ground water during run-off associated with intended use applications is considered minimal to non-existent, due to its percolation through, and resulting capture in soil. Accordingly, the use of this microbial pest control agent on terrestrial plants is not anticipated to negatively impact the quality of drinking water.]

2. Non-dietary exposure. [The potential for dermal exposure to pesticide residues of Bacillus subtilis MBI 600 for the general population, including infants and children, is unlikely as the use sites are limited to agricultural and horticultural applications. In addition, as the microbe is a ubiquitous, naturally occurring soil bacterium, it is likely many individuals have had prior exposure. Accordingly, any potential increase in dermal exposure due to pesticidal use of Bacillus subtilis MBI 600 would be inconsequential. Furthermore, as summarized previously, MBI 600 is of low dermal toxicity - Toxicity Category IV.

Similarly, the inhalation exposure to pesticide residues of Bacillus subtilis MBI 600 for the general population, including infants and children is unlikely because potential use sites are agricultural and horticultural. Also, as stated before, the microbe is a ubiquitous, naturally occurring soil bacterium, and it is likely many individuals have had prior exposure. The acute pulmonary toxicity/pathogenicity testing of Bacillus subtilis MBI 600 demonstrated it is neither toxic, pathogenic nor infective - Toxicity Category IV Therefore, any potential increase in inhalation exposure due to pesticidal use of Bacillus subtilis MBI 600 would be inconsequential.  The results of toxicity testing indicate there is no risk to human health or the environment from Bacillus subtilis MBI 600. It is not toxic to test animals when administered via the oral, dermal, intravenous or pulmonary routes of exposure.  Nor is it infective or pathogenic to test animals when administered via the oral, pulmonary and intravenous routes.  In addition, no reports of hypersensitivity have been recorded from personnel working with this organism.  MBI 600 does not produce recognized toxins, enzymes, or virulence factors normally associated with mammalian invasiveness or toxicity.  The limited survival of MBI 600 and the lack of acute toxicity indicate that both the hazard and the exposure associated with the use of MBI 600 are low.  Non-dietary exposures would not be expected to pose any quantifiable risk due to a lack of residues of toxicological concern.]

E. Cumulative Effects

	[Bacillus subtilis MBI 600 is non-toxic to mammals. Because no mechanism of pathogenicity or toxicity in mammals has been identified for this organism, no cumulative effects from the interaction of residues of this product with other related microbial pesticides are anticipated when this product is used as directed on the label and in accordance with good agricultural/horticultural practices. It is not expected that, when used as directed, Bacillus subtilis MBI 600 would result in residues that are of toxicological concern. The intended use of Bacillus subtilis MBI 600 is to apply it to growing media, seeds, and growing plants and crops for the purposes of disease control.  Bacillus subtilis is widely distributed in the US and around the world.  Application of Bacillus subtilis MBI 600 to seeds, foliage or soil will not result in any significant increases in overall concentrations of Bacillus subtilis in the environment.   The results of toxicity testing indicate there is no risk to human health or the environment from Bacillus subtilis MBI 600. There are no reports of ecological or human health hazards caused by Bacillus subtilis in general or the strain Bacillus subtilis MBI 600 in specific. MBI 600 does not produce significant quantities of extracellular enzymes or possess other virulence factors that would predispose it to cause infection. The absence of acute toxicity or pathogenicity in laboratory animals demonstrates the benign nature of this strain.]

F. Safety Determination

	1. U.S. population. [There is reasonable certainty that no harm to the US population, including infants and children, will result from aggregate exposure to residues of Bacillus subtilis MBI 600 from its use as a microbial pest control agent. The results of toxicity testing indicate there is no risk to human health or the environment from Bacillus subtilis MBI 600. It is not toxic to test animals when administered via the oral, dermal, intravenous or pulmonary routes of exposure.  Nor is it infective or pathogenic to test animals when administered via the oral, pulmonary and intravenous routes. Bacillus subtilis MBI 600 does not produce recognized toxins, enzymes, or virulence factors normally associated with mammalian invasiveness or toxicity. In addition, no reports of hypersensitivity have been recorded from personnel working with this organism.]

	2. Infants and children. [For the same reasons stated previously, there is reasonable certainty that no harm to infants and children will result from aggregate exposure to residues of Bacillus subtilis MBI 600 from its use as a microbial pest control agent.]

G. Effects on the Immune and Endocrine Systems

	[There is no evidence to date suggesting Bacillus subtilis MBI 600 functions in a manner similar to any known hormone, or that it acts as an endocrine disrupter.]

H. Existing Tolerances

      [40 CFR 180.1128 Bacillus subtilis MBI 600; exemption from the requirement of a tolerance.

The biofungicide, Bacillus subtilis  MBI 600 is exempted from the requirement of a tolerance in and on all raw agricultural commodities when applied as a seed treatment on seeds used to grow agricultural crops in accordance with good agricultural practices."]

I. International Tolerances

	[A Codex Alimentarium Commission Maximum Residue Level (MRL) is not required for Bacillus subtilis MBI 600.]


MEMORANDUM
To:		Gil Wood, EPA
From:		Jill Mozier, EC/R Inc.
Date:		November 5, 2012
Subject:	Notes from October 30, 2012 Meeting with EPA and HPBA at RTP, NC ____________________________________________________________________________________
Participants:
John Crouch, HPBA (main presenter)
David Menotti, Crowell & Moring, LLP (Attorney for HPBA, called in)
Bob Ferguson, Ferguson Andors & Co (Product development consultant to HPBA, called in)
Gil Wood, EPA
Mike Toney, EPA
Greg Green, EPA
John Kinsey, EPA
David Cole, EPA
Larry Sorrels, EPA
Amanda Aldrich, EPA
Chebryll Edwards, EPA
Beth Friedman, EC/R
Jill Mozier, EC/R

Synopsis of HPBA position:
John Crouch of Hearth, Patio & Barbecue Association (HPBA)  presented HPBA's power-point "road show" created to educate the states regarding issues impacting the wood heater NSPS (~75% of meeting) and hydronic heater rule concerns (~25% of meeting), and explained that the presentation would be put on a CD to give to the states at the Minneapolis meeting. David Menotti and Bob Ferguson supplemented John Crouch's presentation via phone. EPA asked questions to clarify HPBA's conclusions, as well as clarified EPA's and the state's concerns, as needed. EC/R observed and took notes.

HPBA's main points regarding the wood heater NSPS included that HPBA shares certain common goals with the states and EPA (of improving air quality, replacing uncertified polluting stoves, and continuing to improve the real-world performance of certified stoves), but contends that the research shows that:
 EPA's current test methods are not precise enough to differentiate between 4.5 g/hr and 3.0 g/hr even within the same lab (HPBA claims the variability is +-3 g/hr not +-1 g/hr);
 There is no correlation between certification values and real-world emission rates, and that the ranking of the best performing stoves in the real-world situation are not accurately predicted by the lab certification tests;
 The inherent variability in burning wood (especially cordwood versus cribwood) contributes greatly to the disconnect between real-world and lab results, and even contributes significantly to the lack of same lab precision;
 A standard < 4.5 g/hr is not cost effective ;
 A review of the AP-42 data set, based on comparing in situ measurements with known certification test data for the models measured in the field, shows that while overall certified stoves are better performers, there is no correlation between the certified value and the real world emission rates and that the rank ordering changes between the two measures.
 Tightening the standard (i.e., lowering the NSPS passing grade) or test parameters (e.g., density) would merely increase the cost (decrease available models and make available models more expensive) and not improve certification test precision (exclude some good-performing stoves from market unnecessarily), which would slow change-outs and further disconnect EPA certification with real-world performance;
 EPA Method 28 (M28) requirement for Category 1 runs at a burn rate <1.0 dry kg/hr (based on in-situ test data in development of NSPS) doesn't correspond to the original intent to match real-world use patterns. This is because the in-situ field tests measured the heater temperature at higher (cooler) location on the stack as an indication of the end of the test versus the lab tests using a zero delta weight scale reading as the end of the test. Thus for the same event, the in-situ test values would show shorter burn times than corresponding lab tests. The draft ASTM method increases the minimum burn rate requirement to 1.15 kg/hr; and
 Overall efficiency, unlike combustion efficiency, is not a surrogate for CO emissions, does not correlate to particulate emissions, and is not necessarily precisely measured -- and furthermore including overall efficiency in standard would eliminate ~1/3 of models that currently meet 4.5 g/hr standard.

   HPBA therefore concludes that tightening the NSPS standard is counter-productive to the goals of improving the real-world performance of stoves and improving air quality, and proposes that:
 To improve real-world performance, EPA should focus not on certification numbers but rather on low burn rates and getting away from crib testing altogether (i.e., moving to cordwood);
 M28's low burn rate protocol should be changed to better reflect real-world burning and to better allow for a clean burn by increasing the allowable start-up time during the pre-burn time to provide effective fire-starting draft and hotter start than lab currently requires, and by a modest increase (15%) in the minimum combustion air setting; and
 Overall efficiency (which includes heat transfer efficiency, not only combustion efficiency) should not be added to the standard, but rather merely disclosed to the consumer on the hang tag, which will allow marketplace pressure to drive efficiency improvement and thereby achieve efficiency goals in a few years without the need for enforcement.

   HPBA's main points regarding changes to the proposed Hydronic Heater (HH) standard include that:
 Education is needed (for states) regarding what is and is not a well-operated HH with BSER;
 EPA's HH voluntary program has been a success because tremendous progress has been made in HH emission reductions in a relatively short period (26 cordwood models and 13 manufacturers under voluntary program since 2004); and
 A 0.32 lbs/MMBtu heat output standard represents 90% control, this is the number that EPA had at least implied to manufacturers was the draft NSPS target in 2010, and this is also the limit which is attainable (the lower co-proposed standard of 0.15 lbs/MMBtu will put all U.S. manufacturers but Central Boiler out-of-business if the compliance deadline is immediate);
 Specific (draft) key elements be included in ASTM's Partial Thermal Storage (PTS) Method in order to level playing field between European- and American-made HHs;
 Precision of EPA M28 WHH has not been determined (but it's unlikely that it's more precise than wood stove method due again to inherent variability of wood as fuel);
 Format of standard already indirectly regulates efficiency since Btu is part of units; and
 EPA should not proceed with the 0.15 lbs/MMBtu co-proposal immediately but rather stay with the 0.32 lbs/MMBtu limit as the standard and have a reasonable time for improvements.

   Discussion Highlights (EPA and HPBA):
 EPA noted that SIP planners typically double the certification numbers and would therefore contend that the real-world emission limits are already being considered in SIPs.
 EPA noted that there have probably been technological improvements to wood stoves since 1995 (compared to dataset Dr. James Houck looked at and on which HBPA is basing their assertions). HPBA responded that there has been very little money for R&D so basic woodstove technology is unchanged, and further that the points made regarding the precision of the lab testing are still valid since it's the same test.
 EPA noted that according to a meeting with Hearth & Home Technology at their in-house test lab in Colville, they test on cribs and cordwood both, in order to ensure real world performance in addition to lab performance. Thus, their certification numbers are not that far away from real-world values. HPBA responded that there is almost no data on cordwood in labs using M28.
 HPBA asserted several times that a stricter standard would slow the rate of change-outs of the 6 million uncertified stoves that are still in the field and have 2 to 3 times higher emissions than certified stoves. They note that 86% of PM comes from these 6 million uncertified stoves so change-outs should be a primary goal. EPA responded that OID has been supporting changeouts for over a decade but our partners typically only achieve change-outs on the order of 100 to 150 stoves per project, so how long would it take at that rate to change-out 6 million uncertified stoves?
 EPA cautioned HPBA that allowing companies to manufacture 0.32 lbs/MMBtu hydronic heaters for very long is not the goal of most states given their concern about insults to air quality. Further, EPA cautioned that EPA never stated nor implied the NSPS standard wouldn't go down to 0.15 lbs/MMBtu or even lower. Nonetheless, EPA understands that one of HPBA's concerns regards the timeline needed to meet such a standard. HPBA contends that such a low limit will put almost all manufacturers of HH out of business, that even European models are at ~0.2 lbs/MMBtu, depending on how they are tested, and that there is almost no data to support a 0.15 lbs/MMBtu limit. EPA asked what a reasonable time would be. HPBA noted that "they did not institute a nuclear attack against EPA's earlier discussion of perhaps 5 years."
 EPA is interested in HPBA's position regarding inclusion of a short-term PM emissions testing requirement for hydronic heaters, not as an emission limit, but on order to provide data for future rule making. HPBA noted that data does not currently exist for that form of a standard, but has no problem with data generation effort to inform a later emission standard.
 EPA noted that it would likely not have time to wait for ASTM to finish their development of refined test methods but rather will likely have to proceed without an official ASTM refined method, and further noted that some states' air programs cannot join ASTM. HPBA noted that the ASTM process has some rigor and suggested that the participation question perhaps needed to be asked differently to states' attorneys generals regarding ASTM membership because some of these same states have, for example, transportation agencies that are ASTM members. HPBA noted that they will contact Mary McKiel, the EPA NTTA Coordinator, for assistance in this matter.
 HPBA is still working on their independent cost analysis and trying to make it consistent with OMB guidelines. EPA noted that OMB commonly looks at certain parameters, e.g., 5[th] year impacts, so that they have comparable analysis between rules. The group also discussed whether a longer model life could be considered in the analysis.
 In response to EPA question regarding whether certain add-on technologies would be less expensive to manufacture compared to a complete re-design, HPBA responded that EPA should be wary of such add-ons because consumers will not necessarily keep sophisticated technology in proper working order.  HPBA will respond more formally to this EPA question in docket.
 HPBA explained that in order to move away from crib wood testing, there are advantages to a middle-ground cordwood "off-ramp" in the NSPS which gives industry the option (not requirement) of testing using cordwood instead of crib. This bridge concept could incentivize experts in the field and create a generation of appliances based on cordwood rather than crib, but frankly industry is currently cautious to adopt and leave familiar crib-based testing system. In the meantime, HPBA assured EPA that the industry was burning cordwood and collecting data. EPA expressed support for cordwood option and for industry collecting data. In response to industry's concern that some states would jump to requirement of cordwood testing, EPA noted that EPA cannot tell the states to not do so and suggested that HPBA might consider approaching states like Washington and Oregon directly for discussions of whether they could assure that cordwood would not yet be required as the only method, but rather that there be a transition period before agreed-upon Year X when cordwood testing would be the requirement. EPA noted that OR and WA may be receptive.
 Issues in testing with cordwood include loading density, operating at the low burn rate and start up can be more difficult.
 EPA agrees that old existing woodstoves are a major problem and encourages thinking creatively about the standard, trade-offs, etc. (e.g., like the averaging concept using for fleet vehicles).
 HPBA suggested removing referencing numbers from hang tags and using a focus group at the Expo in Orlando (spring 2013) to help simplify and clarify tags, which are currently too complicated in their opinion. EPA thought that it would be possible to participate in the focus group effort.
 EPA wondered about certified installers of woodstoves to ensure proper installation, chimney height, and to educate consumer about proper burn techniques, etc. HPBA could envision such a system with, for example, signed legal paperwork by installer being sent to EPA.


  SEQ CHAPTER \h \r 1 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

OFFICE  OF

PREVENTION, PESTICIDES AND

TOXIC SUBSTANCES

  SEQ CHAPTER \h \r 1 	February 14, 2008

	PC Code: 122001

	DP Barcode D334277

MEMORANDUM

Subject: 	Tier I Sulfometuron Methyl Drinking Water Assessment for
Reregistration Eligibility Decision Document (slightly revised)

To:		John Pates, Review Manager

		Special Review and Reregistration Division (SRRD) (7505P)

From:		Michael R. Barrett, Ph.D., Senior Chemist

		Environmental Risk Branch V

Environmental Fate and Effects Division (7507P)

Thru:		Mah Shamim, Ph.D., Chief

		Environmental Risk Branch V

Environmental Fate and Effects Division (7507P)

This memo presents the Tier I Estimated Drinking Water Concentrations
(EDWCs) of sulfometuron methyl (CAS No. 74222-97-2), calculated using
FIRST (surface water) and SCI-GROW (ground water) for use in the human
health risk assessment.   Exposure estimates have also been generated
for the total residues of sulfometuron methyl which include sulfometuron
and major degradates such as a pyrimidine amine, a sulfonamide
degradate, and saccharin (See Appendix 1 for full chemical names and
structures).  Sulfometuron methyl is a non-selective herbicide for use
in forestry plantings, on rights-of-way, industrial sites, around
buildings, railroads, pipelines, etc.

Exposure to sulfometuron methyl parent and sulfometuron total residues
has been estimated with FIRST (FQPA Index Reservoir Screening Tool;
v.1.1.0; dated 1/1/2007) and SCI-GROW (Screening Concentration In GROund
Waterm v2.3), results are summarized below.

Parent Exposure estimates:

For surface water, the acute value is 31.98 ppb and the chronic is 14.51
ppb.  The groundwater screening concentration is 0.33 ppb. These values
represent upper-bound estimates of the concentrations that might be
found in surface water (a vulnerable reservoir) and ground water due to
the use of sulfometuron methyl at the maximum allowable rate within the
watershed.

Parent + Degradate exposure estimates:

For surface water, the acute value is 32.35 ppb and the chronic is 21.82
ppb.  The groundwater screening concentration is 1.13 ppb. These values
represent upper-bound estimates of the concentrations that might be
found in surface water (a vulnerable reservoir) and ground water due to
the use of sulfometuron methyl at the maximum allowable rate within the
watershed.

Data Gaps:

The available environmental fate studies do not provide sufficient data
for modeling of individual degradates of sulfometuron methyl that could
be of toxicological concern.  Should such estimates be required in the
future, than additional environmental fate studies specific to the
degradates of concern may be required.

Error Correction Note:

This document replaces the October 31, 2007 Drinking Water Assessment.
The only revision is that a duplicate (and mislabeled) degradate entry
in Appendix 1 has been deleted.

Sulfometuron methyl drinking water assessment

Nature of Chemical Stressor

Sulfometuron methyl, (2-[[[[(4,6-Dimethyl-2-pyrimidinyl) amino]
carbonyl] amino] sulfonyl] benzoic acid, methyl ester), is a
broad-spectrum pre- and post-emergence herbicide that is currently
registered for weed control in forestry and non-food crop situations,
including vegetative management in right of ways and railroads.  It is
used to control a variety of broad-leaf weeds and grasses.  Similar to
other sulfonylurea herbicides, the mode of action of sulfometuron methyl
involves inhibiting the activity of the enzyme acetolactate synthase
(ALS), which in turn inhibits the synthesis of selected amino acids that
are required for cell proliferation in plants.

Sulfometuron methyl is formulated as a water dispersible granule (WDG)
and applied using a variety of methods including helicopter, fixed-wing
aircraft, ground spray (boom and backpack) and spot treatment.  It is
generally applied once per year for non-crop areas in years that
vegetation management is needed. In some instances (weed escapes) a
second application may be made, but all products limit the total
quantity of sulfometuron methyl that may be applied (from any source) to
6 ounces of active ingredient per acre per year (0.375 lb ai/A).
Therefore, application rates in general forestry, and for site
preparation and/or release in conifer, hardwood and Christmas tree
plantations, will vary significantly depending upon the specific purpose
of the application and the desirable tree species.  In forestry, uses
can be similar to plantation sites, but may also include the maintenance
of access routes and fire breaks.  It is further noted that use rates
can also vary with climate and soil type.

Environmental Fate and Transport Characterization

The body of environmental fate data submitted demonstrate sulfometuron
is mobile and persistent in the environment (Appendix 2). Sulfometuron
methyl is more soluble in neutral and alkaline water than in acidic
water. The major route of dissipation for sulfometuron methyl is
believed to be aerobic and anaerobic degradation / metabolism in soil
and water (pseudo first-order degradation half-lives generally around 2
to 6 months), with hydrolysis potentially dominant under acidic
conditions. First-order rate aerobic soil metabolism half lives range
from 52 to 58 days in two laboratory studies (technically both with the
same soil type, but measured in two independent studies several years
apart).  In comparison, dissipation half-lives in the field ranged from
44 to 128 days at four sites (when considering only the residues
remaining in the upper 15 cm of topsoil). The longer persistence of
residues in the soil at one field site indicates that degradation in
some soils is slower under some field conditions than observed in many
of the laboratory studies. Sulfometuron methyl is subject to hydrolysis
at environmental pHs; with significantly more rapid hydrolysis occurring
under acidic conditions (e.g., a hydrolysis half-life of 9 days at pH 5
and 139 days at pH 7).  However, laboratory and field studies in soil or
sediment / water environments, albeit all at measured pHs somewhat
greater than 5, do not generally show as rapid degradation as measured
in the pH hydrolysis study.

.

Metabolism in the aquatic environment is variable, ranging from
half-life of 17 to 104 days in anaerobic conditions and 9 to 187 days
for aerobic conditions (the more rapid degradation with a 9-day total
system half-life took place in a test system with sediment pH of 5.4 and
water pH of 7.6).  Although sulfometuron methyl persistence is expected
to generally increase with higher soil pH (rotational crop restrictions
for many other sulfonylureas, which are all weak acids, reflect this), a
consistent trend was not found in the available studies.

Soil retention of sulfometuron methyl is low, with Freundlich adsorption
KF values ranging between 0.15 and 2.1 ml/g in four test soils with soil
organic carbon content ranging between 0.6 and 2.6 percent.

Sorption was not found to be strongly dependent on any of the major
properties of the tested soils in the registrant-submitted studies. The
pKa of sulfometuron methyl is 5.4, and theoretically, adsorption may
increase in very acidic soils where the methyl ester form of
sulfometuron would predominate.  However, the pH range of the four test
soils in the batch equilibrium adsorption / desorption study was only
6.7 to 7.7. The published literature do seem to show more of a
relationship of sulfometuron methyl and other sulfonylureas to mobility
in soil; Weber et al. (2004) have reviewed the literature and concluded
that there is a consistent relationship between pH and mobility of
sulfonylureas (“NHSO2 acid herbicides” means sulfonylurea
herbicides):

OM and pH were also the primary soil properties in best-fit Kd equations
obtained for five of the six NHSO2 acid herbicides, with all three soil
properties utilized in the Kd equation for sulfometuron-methyl. Cl was
also one component of the Kd equation for sulfometuron-methyl, but Cl
and pH were also related soil properties. As was the case for the COOH
acid herbicides, sorption increased as OM increased or as pH decreased.

Other abbreviations used in the above excerpt from the Weber et al.
article:

OM = Soil organic mater content

Cl = Chloride ion concentration

COOH acid herbicides = Herbicides with a carboxy acid functional group
such as 2,4-D and Imazethapyr

In terrestrial field dissipation studies at four US sites, leaching of
parent sulfometuron methyl occurred at measurable concentrations (>10
ppb in depth increments from 15 to 90 cm) was noted at each test site.
Leaching of the degradates was not evaluated in the field dissipation
studies.

Sulfometuron persistence in water indicates that if, either via spray
drift or any runoff event, sulfometuron methyl reaches surface water, it
may persist for a few weeks to several months and present some concern
to surface water resources.  The fairly low use rate (maximum annual
rate of 0.375 lb ai/A) and the apparent typical use pattern of applying
in only one or two years out of a several year period should limit the
actual exposure of sulfometuron methyl residues in surface water
(however, note that sulfometuron methyl could negatively affect certain
sensitive plants at very low exposure levels because it is such a potent
herbicide with respect to many plant species).

Volatility studies were not reported.  However, based its chemical
properties, volatilization is not expected to be a route of dissipation
of sulfometuron methyl in water or soils.

Sulfometuron methyl degrades to CO2 under aerobic, non-sterile
conditions (relatively little mineralization occurs under sterile
conditions), but with significant accumulation of intermediate
degradates, including a sulfonamide and saccharin from the phenyl ring
part of the parent molecule and a pyrimidine amine from the pyrimidine
ring portion (see Appendix 1). For the phenyl ring labeled studies, CO2
was up to 28 to 44 % of applied at study termination whereas for the
pyrimidine-ring labeled studies CO2 was up to 53% of applied at study.

The only submitted studies directly evaluating the fate of sulfometuron
methyl degradates were adsorption / desorption studies on the pyrimidine
amine and saccharin. The soil retention characteristics of two of the
sulfometuron methyl degradates were studied in batch equilibrium
adsorption / desorption studies: saccharin Kfs were 0.03 to 0.27 and the
pyrimidine amine Kfs were 0.17 to 3.70 in the four test soils. This
means saccharin would be slightly more mobile and the pyrimidine amine
slightly less mobile than parent (Kfs of 0.15 to 2.12 in the same four
soils)

Drinking Water Exposure Estimation

While some monitoring data are available, the data are not targeted to
watersheds known to present the highest exposure potential for
sulfometuron methyl.  Consequently, EFED’s Tier I models were used for
this drinking water exposure assessment.

Model Descriptions

Surface Water:  The FIRST (FQPA Index Reservoir Screening Tool, Version
1.1.0) model by the Environmental Fate and Effects Division (EFED) of
the USEPA Office of Pesticide Programs (OPP) was used to assess
potential for contamination of surface drinking water sources from the
proposed sulfometuron methyl use.

FIRST is a single-event model (one runoff event), but can account for
spray drift from multiple applications.  FIRST is hardwired to represent
the Index Reservoir, a standard water body used by the Office of
Pesticide Programs to assess drinking water exposure (Office of
Pesticide Programs, 2002).  It was based on a real reservoir, Shipman
City Lake in Illinois, which was known to be vulnerable to pesticide
contamination (with ample confirmation from pesticide monitoring data).
The single runoff event moves a maximum of 8% of the applied pesticide
into the reservoir.  This amount can be reduced due to degradation on
the field and the effects of binding to soil in the field.  FIRST also
uses a Percent Cropped Area (PCA) factor to adjust for the area within
the watershed that is planted to the modeled crop.  The national default
PCA of 0.87 was applied in this assessment.

Ground Water:  Sulfometuron methyl concentrations in ground water were
estimated by the Screening Concentration in Ground Water (SCI-GROW v2.3,
Jul. 29, 2003) model.  SCI-GROW is a regression model used as a
screening tool to estimate pesticide concentrations found in groundwater
used as drinking water.  SCI-GROW was developed by fitting a linear
model to ground water concentrations with the Relative Index of Leaching
Potential (RILP) as the independent variable.  Groundwater
concentrations were taken from 90-day average high concentrations from
Prospective Ground Water studies.  The RILP is a function of aerobic
soil metabolism and the soil-water partition coefficient.  The output of
SCI-GROW represents the concentrations sulfometuron methyl residues that
might be expected in shallow unconfined aquifers under sandy soils.

Further information on these models can be found at the EFED water model
website at http://   HYPERLINK
"http://www.epa.gov/oppefed1/models/water/html"
www.epa.gov/oppefed1/models/water/html .

Model Inputs and Results (Drinking Water Estimated Concentrations)

Key inputs for FIRST modeling, including data sources and parameter
estimation methods (if applicable) are summarized in   REF _Ref177972956
\h  Table 1  and results for parent sulfometuron methyl are given in
REF _Ref181591758 \h  Table 3  and for the total residues in   REF
_Ref181591770 \h  Table 4 .  These are conservative estimates, in most
cases the potential exposure will be lower because the fraction of
watershed land which represents legally possible sulfometuron methyl use
sites, and furthermore,  represents actual sulfometuron methyl use sites
in any given year is smaller than 0.87, the default percent crop (or use
site) area that needs to be used.

For ground water, SCI-GROW modeling inputs are presented in   REF
_Ref178394075 \h  Table 2  and Tier I estimated concentrations for
drinking water arising from ground water are provided for parent
compound in   REF _Ref181591758 \h  Table 3  and for total residues in
REF _Ref181591770 \h  Table 4 .  The predicted exposure levels are lower
than for surface water sources for drinking water.

Care needs to be used in assessing risk to sulfometuron total residues
including degradates from the DWECs presented here. The nature of the
total residue modeling method means that the total residues are
estimated as parent equivalents.  Similar weight / volume drinking water
estimated concentrations for individual degradates which arise from
fractionation of the parent molecule would be substantially less (if
they could be calculated from the available environmental fate data).
Given the limited environmental fate data on the degradates, no
estimation of individual degradate concentrations is possible at this
time.  The DWECs in these tables cannot be manipulated to provide
separate degradate and parent concentrations.

Table   SEQ Table \* ARABIC  1 .  FIRST input parameters for modeling
(DWECs).

Input Parameter	Value*	Reference

Molecular Weight (gram mole -1)	364.38	MRID: 416728-02

Vapor Pressure (torr)	5.4x10-16

	Aerobic Soil Metabolism Half-life (days)	61	90% Upper Confidence Limit
of the mean of measured values  (MRIDs 42091401; 43174102 and 245375)

Water column Half-life (days)

(Aerobic Aquatic Metabolism half-life)	292	90% Upper Confidence Limit of
the mean of measured values  (MRIDs 42091403 and 43174103 )

Benthic sediment Half-life (days)

(Anaerobic Aquatic Metabolism half-life)	76	90% Upper Confidence Limit
of the mean of measured values  (MRIDs 43174102, 245375, 42091402, and
43188601)

Application Rate (lb a.i. / A)	Up to 0.375	Efficiency= 0.99 for ground
spray, 0.95 for aerial.

Application Number (Method of application)	    One, two or three
Product Label; typical use. Maximum annual rate of 0.375 lb ai/ A was
used in each case.

Application method; Depth of Incorporation (cm)	Aerial: NA

Ground: 0	Product Label; typical use.

Spray Drift (fraction)	0.16 (GS), 0.064 (aerial)	Default values for the
FIRST model. (GS= ground spray) – Not a user input.

Solubility (ppm)	244	Highest solubility was recorded for alkaline water
(12,500 ppm at pH 8.6).  However, experience from other studies
indicates these experimental values are too high.

Koc (L Kg-1)	35	Lowest Koc value of the three non-sand soils tested
(MRID 42789301). Koc model was determined to be appropriate.

Hydrolysis Half-life @ pH 7 (days)	139 days

MRID 42715201.

Direct Aqueous Photolysis Half-life(days)	Stable	Maximum dark control
corrected value (MRIDs 42182401 and 43174101)

Fate data values are as per Guidance for Selecting Input Parameters in
Modeling the Environmental Fate and Transport of Pesticides; Version II
February 28, 2002.

Table   SEQ Table \* ARABIC  2 . SCI-GROW modeling inputs.

Input Parameter	Value*	Reference

Aerobic Soil Metabolism Half-life (days)	55.2

(136 for total residues)	Mean of measured values  (MRIDs 42091401;
43174102 and 245375)

Application Rate (Kg a.i. / ha)	0.41	Maximum permitted single (and
annual) rate.

Application Number (Method of application)	    One	Typical use.

Koc (L Kg-1)	73.4

(same for total residues)	Median of four values (MRID 42789301).

Table   SEQ Table \* ARABIC  3 .  Tier I EDWCs for sulfometuron methyl
from forestry or rights of way uses.

		Chemical	Application	Peak Day (Acute)	Annual Average (Chronic)

Surface Water	 Rate (lb a.i./A)	   Number  	Interval 	Concentration
(µg/L)

Aerial	0.375 	1	NA	31.96	14.51

Ground	0.375 	1	NA	31.98	14.50

Aerial	0.188	2	30	27.57	12.52

Aerial	0.125	3	90	16.53	7.5

Aerial	0.125	3	45	21.39	9.7

Ground Water

	Aerial or ground	0.375	1	NA	0.33	0.33

Table   SEQ Table \* ARABIC  4 . Tier I EDWCs for sulfometuron total
residues from forestry or rights of way uses*.

Chemical	Application	Peak Day (Acute)	Annual Average (Chronic)

Surface Water	 Rate (lb a.i./A)	   Number  	Interval 	Concentration
(µg/L)

Aerial	0.375 	1	NA	32.35	21.82

Aerial	0.188	2	30	30.21	20.38

Ground Water

	Aerial or ground	0.375	1	NA	1.13	1.13

* Includes sulfometuron methyl, sulfometuron free acid, sulfometuron
pyrimidine amine, sulfometuron sulfonamide, and saccharin.

Review of Monitoring Data

In the most widespread monitoring survey available, sulfometuron methyl
was detected only rarely (2 of 132 samples from 52 sites – mostly
Midwestern US streams and rivers, but including some reservoirs as
well); see Battaglin et al. (2000).  The maximum concentration of
sulfometuron methyl detected was 0.018 ug/L; but it is not known how
much sulfometuron methyl usage was associated with the watersheds
included in this monitoring survey.

Blomquist et al. (2001) in a monitoring study of 12 reservoir systems
across the United States found sulfometuron methyl occurred above the
minimum reporting limit of 0.05 ug/L in 12% of the samples collected
with a maximum concentration of 0.16 ug/L and a 95th percentile
concentration of 0.10 ug/L.  This study focused on drinking water
supplies and the results are directly relevant to this drinking water
assessment; however these data cannot be used for a conservative
(protective) estimate of drinking water exposure since there is no basis
to conclude that the study sites represent watersheds where exposure to
sulfometuron methyl is the highest.

APPENDIX 1: Structures and Chemical Names of Sulfometuron methyl
Metabolites

Chemical Structures

Trivial or common names

Company id or similar alternate names

Full chemical names

Sulfometuron methyl

DPX-T5648; DPX-5648; IN-T5648; IN T5648-18

Methyl 2-(4,6-dimethylpyrimidin-2-ylcarbamoylsulfamoyl)benzoate

Saccharin

IN-581

1,2-Benzisothiazol-3(2H)-one, 1,1-dioxide

Sulfometuron pyrimidine amine

IN-X0993; IN-X993; PA

4,6-Dimethyl-2-pyrimidinamine

4,6-dimethyl-2-pyrimidinamine

Sulfometuron sulfonamide

IN-D5803; SA; methyl phenylsulfonamide

Methyl 2-(aminosulfonyl)benzoate.

2-(Aminosulfonyl)-benzoic acid, methyl ester

Pyrimidine-ol

IN-11859

4,6-Dimethyl-2-pyrimidinol

Sulfometuron free acid

FA-SM; IN-T6385

2-[[[[(4,6-Dimethyl-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-benzoic
acid

Free acid Sulfonamide

FA-Sulfonamide; Free acid; IN-D5119

2-(Aminosulfonyl)benzoic acid

APPENDIX 2: Environmental Fate Summary Table

Table   SEQ Table \* ARABIC  5 . Key results of sulfometuron methyl
environmental fates studies.

Parameter

[Guideline #]	Value1	MRID(s)

Hydrolysis

[161-1]

	t½= 8.8 days (LL) @ 25 oC, pH 5;

t½=139 days (LL) @ 25 oC, pH 7;

t½= 224 days (LL) @ 25 oC, pH 9.

Major degradates (from cleavage of the sulfonylurea bridge):

Sulfonamide – only in acidic water

Saccharin – all pH levels

Pyrimidine amine – all pH levels

42715201

Direct photolysis in water

[161-2]	Combined labels results:

t½= 428 days (LL) @ 24 oC, pH 5;

t½= stable @ 24 oC, pH 7;

t½= stable @ 24 oC, pH 9.

(calculated by the difference in degradation rates between irradiated
and dark controls and adjusting for typical light levels on sunny days)

Major degradates (irradiated water):

pH 5:  sulfonamide, pyrimidine amine;

pH 7:  none;

pH 9:  none.

42182401

43174101

Photolysis on soil

[161-3]	t½= 72.1 days (LL) @ 25 oC,

Study duration was 33 days, substantial degradation occurred in dark
controls and the calculated photolysis half-life represents the
difference in the dissipation rate in the irradiated and the dark
control samples.

Major degradates (from cleavage of the sulfonylurea bridge):

Saccharin reached a maximum of 48.4% of the applied at 33 days (study
termination.)

Pyrimidine amine reached a maximum of 53.1% at 33 days (study
termination.)

There was no substantial difference in the degradation pathway of
sulfometuron methyl between the irradiated- and the dark control soil.

No other degradate accounted for >4% of the applied radioactivity
regardless of whether the phenyl ring or the pyrimidine ring was
14C-labeled.

41420601

Aerobic soil metabolism

[162-1]

	Study with [pyrimidine-2-14C] Sulfometuron Methyl

Soil: Keyport Silt loam (pH 6.3, 1.6% O.C.) from Delaware

First Order t½:			57.8 days (LL) (r2 = 0.9239).

Observed DT50:		23 days.

Observed DT90:		110 days.

Sterile soil First Order t½: 	364 days (LL)

Major transformation products:

Pyrimidine amine (maximum 41.0% of the applied)

Pyrimidine-ol (maximum 10.5% of the applied).

	CO2 (maximum 53.1% of applied).

Minor transformation products:

Free acid sulfometuron methyl.

Pyrimidine urea.

42091401

Aerobic soil metabolism

[162-1]

	Study with U- 14C-phenyl-labeled Sulfometuron Methyl

Soil: Keyport Silt loam (pH 6.4, 1.6 % O.C.) from Delaware (0.12 mg
a.i./kg).

First Order t½:		52.5 days (LL) (r2 = 0.9239).

Observed DT50:	29 days.

Observed DT90:	162 days.

Major transformation products:

Sulfonamide.

Saccharin.

Free acid sulfonamide plus urea (1.0 mg a.i./Kg only).

	CO2.

Minor transformation products:

Free acid sulfonamide plus urea (0.12 mg a.i./Kg only)

43174102 and 245375

Anaerobic aquatic metabolism

[162-3]	Study  performed with [pyrimidine-2-14C] Sulfometuron Methyl

Matrix: Bradenton Pond water-sand sediment.

First Order t½:			37.4 days (LL) (r2 = 0.6125).

Observed total system DT50:	22 to 61 days (inconsistent decline data).

Observed total system DT90:	102 days.

Matrix: Landenberg Pond water-sandy loam sediment.

First Order t½; total system:	17.1 days (LL) (r2 = 0. 0.6394).

Observed total system DT50:	6.1 days.

Observed total system DT90:	21.7 days.

Major transformation products (both systems):

free acid sulfometuron methyl.

pyrimidine amine.

Minor identified transformation products:

pyrimidine-ol.

CO2.

42091402 and 43188601

Anaerobic aquatic metabolism

[162-3]	Study with [phenyl-U-14C] Sulfometuron Methyl

Matrix: Pond water-sandy loam sediment from Bradenton, Florida.

(water pH 5.5 .  Sediment: pH 5.1; O.C. = 5.9 %).

First Order t½; total system:	104 days (LL) (r2 = 0.4883)*.

Observed DT50 in total system:	ca. 21 days.

Sterile t½; total system:	44 days (LL)

* Based upon limited and inconsistent data.

Matrix: Pond water-silt loam sediment from Landenberg, Pennsylvania.

(water pH 5.8 .  Sediment: pH 5.6; O.C. = 2.1 %).

First Order t½; total system:	87 days (LL) (r2 = 0.3577).

Observed DT50 in total system:	ca. 28 days.

Sterile t½; total system:	175 days (LL)

Matrix: Pond water-loam sediment from Saskatoon, Canada. (water pH 8.3 .
  Sediment: pH 7.8; O.C. = 0.9 %).

First Order t½; total system:	77 days (LL) (r2 = 0.5853).

Observed DT50 in total system:	ca. 70 days.

Sterile t½; total system:	399 days (LL)

Matrix: Pond water-silt loam sediment from Walnut Grove, Tennessee.
(water pH 5.5 .   Sediment: pH 5.1; O.C. = 0.5 %).

First Order t½; total system:	73 days (LL) (r2 = 0.5691).

Observed DT50 in total system:	ca. 28 days.

Sterile t½; total system:	95 days (LL)

Major transformation products:

	saccharin.

	free acid sulfonamide.

Minor identified transformation products:

	Methyl-2-aminocarbonyl(aminosulfonyl)benzoate.

4413010-20 (143540)

Aerobic aquatic metabolism

[162-4]	Study  performed with [pyrimidine-2-14C] Sulfometuron Methyl

Matrix used: Pond water-silt loam sediment (Landenberg, acidic system).

First Order t½; total system:	9.2 days (LL) (r2 = 0.94).

Observed DT50 in total system:	15 days.

Observed DT90 in total system:	31 days (extrapolated).

Major transformation products:

Pyrimidine amine (pyrimidine label).

Hydroxymethyl-pyrimidine sulfometuron methyl.

Free acid sulfonamide (phenyl label).

Sulfonamide (phenyl label).

Minor identified transformation products:

CO2.

Matrix used: Pond water-sand sediment (Bradenton, alkaline system).

First Order t½; total system:	187.3 days (LL) (r2 = 0.5713).

Observed DT50 in total system:	>39 days.

Major transformation products:

Pyrimidine amine (pyrimidine label).

Free acid sulfonamide (phenyl label).

Minor identified transformation products:

Hydroxymethyl-pyrimidine sulfometuron methyl.

Sulfonamide (phenyl label).

CO2.

42091403 and 43174103

Adsorption/

Desorption

(Kd and

Koc in L Kg-1)

	Parent sulfometuron methyl:

Soil type:  Chino Sandy loam; pH 7.1, organic carbon 1.0%.

Adsorption Kd:			0.35.

Adsorption Koc:			35.

Freundlich adsorption KF:	0.153.

Freundlich adsorption KFoc:	14.7.

Soil type:  Fargo silt loam ; pH 7.7, organic carbon 2.6%.

Adsorption Kd:			2.07.

Adsorption Koc:			79.6.

Freundlich adsorption KF:	2.12.

Freundlich adsorption KFoc:	83.2.

Soil type:  Miaka Sand ; pH 7.0, organic carbon 0.6%.

Adsorption Kd:			Not applicable.

Adsorption Koc:			Not applicable.

Freundlich adsorption KF:	0.508.

Freundlich adsorption KFoc:	87.6.

Soil type:  Tama Silt loam ; pH 6.7, organic carbon 1.5%.

Adsorption Kd:			0.79.

Adsorption Koc:			52.7.

Freundlich adsorption KF:	0.974.

Freundlich adsorption KFoc:	67.2.

	42789301

Adsorption/

Desorption

Of Degradates

  SEQ CHAPTER \h \r 1 Pyrimidine amine

Soil type:  Chino Sandy loam.

Freundlich adsorption   KF:  3.3.

Freundlich adsorption KFoc:  315.

Soil type:  Fargo Silt loam.

Freundlich adsorption KF: 3.7.

Freundlich adsorption KFoc:  145.

Soil type:  Miaka Sand.

Freundlich adsorption KF:	0.17.

Freundlich adsorption KFoc:  29.4.

Soil type:  Tama Silt loam.

Freundlich adsorption KF:	2.9.

Freundlich adsorption KFoc:  203.

  SEQ CHAPTER \h \r 1 Results Synopsis: [14C]Saccharin

Soil type:  Chino Sandy loam.

Freundlich adsorption KF:	0.11.

Freundlich adsorption KFoc:  10.5.

Soil type:  Fargo silt loam.

Freundlich adsorption KF:	0.27.

Freundlich adsorption KFoc:  10.6.

 Soil type:  Miaka Sand.

Freundlich adsorption KF:	0.033.

Freundlich adsorption KFoc:  5.73.

Soil type:  Tama Silt loam.

Freundlich adsorption KF:	0.13.

Freundlich adsorption KFoc:  8.72.

42789301

Terrestrial Field/Lysimeter

Dissipation 2	Greenville, MS silty clay loam soil: pH 6.7, 0.6% O.C.

Half-life: 49.2 days (LL) (based on 0- to 359-day data);

12.2 days (LL) (based on 0- to 91-day data).

DT90:	32 days

Major transformation products detected (>0.01 ppm):

Sulfometuron free acid (SFA)

Pyrimdine amine (PYA)

Sulfonamide IN-D5803 (SFN)

Saccharin IN-581 (SCC)

Rochelle, IL silty clay loam soil: pH 6.8, 1.0% O.C.

Half-life: 128 days (based on 0- to 723-day data, residues in 0-15 cm
depth only);

14.4 days (based on 0- to 90-day data).

DT90:	35 days

Major transformation products detected (>0.01 ppm):

PYA, SFN, and SCC

Uvale, TX clay soil: pH 7.9, 1.3% O.C.

Half-life:  53.3 days (LL) (based on 0- to 447-day data);

13.0 days (LL) (based on 0- to 90-day data).

DT90:	25 days

Major transformation products detected (>0.01 ppm):

PYA, SFN, and SCC

Maldera, CA sandy loam soil: pH 7.8, 0.7% O.C.

Half-life: 44.1 days (LL) (based on 0- to 420-day data);

22.9 days (LL) (based on 0- to 180-day data).

DT90:	55 days

Major transformation products detected (>0.01 ppm):

PYA, SFN, and SCC	Numbers 43212101 and 43637101

1 LL = “Log-linear” degradation rate calculation; process of
calculating degradation rates and half-lives from linear regression of
log-transformed concentration measurements over time. This provides a
first-order type of measurement of pesticide decline.

2 For these field dissipation studies, differences between half-lives
measured over various time durations apparently reflect both slowing of
degradation at lower temperatures and a large variability in measured
concentrations; also, a 2-compartment degradation model for adsorbed and
dissolved sulfometuron is quite possibility more appropriate (little
dissipation of the remaining residues in the topsoil occurred during the
second year of these studies, for example). A 2-compartment model was
not used to represent dissipation rate here because the data are not
sufficient robust (e.g., very high variability between replicate
measurements), the effects of weather changes on degradation rate cannot
easily be isolated, and the amount of residues lost through dissipation
out of the topsoil also cannot be separated from the amount lost to
degradation.

APPENDIX 3: Modeling Input and Output

FIRST Modeling Input and Output Files

Sulfometuron methyl parent, Single application, Aerial.

RUN No.   1 FOR Sulfometuron met ON   Forest        * INPUT VALUES *

   --------------------------------------------------------------------

    RATE (#/AC)   No.APPS &   SOIL  SOLUBIL  APPL TYPE  %CROPPED INCORP

     ONE(MULT)    INTERVAL    Koc   (PPM )   (%DRIFT)     AREA    (IN)

   --------------------------------------------------------------------

   .375(   .375)   1   1      35.0  244.0   AERIAL(16.0)  87.0    .0

   FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

   --------------------------------------------------------------------

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)  RAIN/RUNOFF  (RESERVOIR)  (RES.-EFF)   (RESER.)   (RESER.)

   --------------------------------------------------------------------

     61.00        2          N/A       .00-     .00   292.00    292.00

   UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0  JAN 1, 2007

   --------------------------------------------------------------------

        PEAK DAY  (ACUTE)      ANNUAL AVERAGE (CHRONIC)

          CONCENTRATION             CONCENTRATION

   --------------------------------------------------------------------

             31.962                     14.508

Sulfometuron methyl parent, Single application, Ground.

   RUN No.   3 FOR Sulfometuron met ON   Forest - G    * INPUT VALUES *

   --------------------------------------------------------------------

    RATE (#/AC)   No.APPS &   SOIL  SOLUBIL  APPL TYPE  %CROPPED INCORP

     ONE(MULT)    INTERVAL    Koc   (PPM )   (%DRIFT)     AREA    (IN)

   --------------------------------------------------------------------

   .375(   .375)   1   1      35.0  244.0   GROUND( 6.4)  87.0    .0

   FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

   --------------------------------------------------------------------

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)  RAIN/RUNOFF  (RESERVOIR)  (RES.-EFF)   (RESER.)   (RESER.)

   --------------------------------------------------------------------

     61.00        2          N/A       .00-     .00   292.00    292.00

   UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0  JAN 1, 2007

   --------------------------------------------------------------------

        PEAK DAY  (ACUTE)      ANNUAL AVERAGE (CHRONIC)

          CONCENTRATION             CONCENTRATION

   --------------------------------------------------------------------

             31.980                     14.500

Sulfometuron methyl parent, 2 applications, Aerial.

   RUN No.   8 FOR Sulfometuron met ON   Forest - A    * INPUT VALUES *

   --------------------------------------------------------------------

    RATE (#/AC)   No.APPS &   SOIL  SOLUBIL  APPL TYPE  %CROPPED INCORP

     ONE(MULT)    INTERVAL    Koc   (PPM )   (%DRIFT)     AREA    (IN)

   --------------------------------------------------------------------

   .188(   .321)   2  30      35.0  244.0   AERIAL(16.0)  87.0    .0

   FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

   --------------------------------------------------------------------

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)  RAIN/RUNOFF  (RESERVOIR)  (RES.-EFF)   (RESER.)   (RESER.)

   --------------------------------------------------------------------

     61.00        2          N/A       .00-     .00   292.00    292.00

   UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0  JAN 1, 2007

   --------------------------------------------------------------------

        PEAK DAY  (ACUTE)      ANNUAL AVERAGE (CHRONIC)

          CONCENTRATION             CONCENTRATION

   --------------------------------------------------------------------

             27.573                     12.519

Sulfometuron methyl parent, 3 applications, 90-day interval,  Aerial.

   RUN No.  10 FOR Sulfometuron met ON   Forest - a    * INPUT VALUES *

   --------------------------------------------------------------------

    RATE (#/AC)   No.APPS &   SOIL  SOLUBIL  APPL TYPE  %CROPPED INCORP

     ONE(MULT)    INTERVAL    Koc   (PPM )   (%DRIFT)     AREA    (IN)

   --------------------------------------------------------------------

   .125(   .186)   3  90      35.0  244.0   AERIAL(16.0)  87.0    .0

   FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

   --------------------------------------------------------------------

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)  RAIN/RUNOFF  (RESERVOIR)  (RES.-EFF)   (RESER.)   (RESER.)

   --------------------------------------------------------------------

     61.00        2          N/A       .00-     .00   292.00    292.00

   UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0  JAN 1, 2007

   --------------------------------------------------------------------

        PEAK DAY  (ACUTE)      ANNUAL AVERAGE (CHRONIC)

          CONCENTRATION             CONCENTRATION

   --------------------------------------------------------------------

             16.532                      7.512

Sulfometuron methyl parent, 3 applications, 45-day interval,  Aerial.

   RUN No.  11 FOR Sulfometuron met ON   Forest aer    * INPUT VALUES *

   --------------------------------------------------------------------

    RATE (#/AC)   No.APPS &   SOIL  SOLUBIL  APPL TYPE  %CROPPED INCORP

     ONE(MULT)    INTERVAL    Koc   (PPM )   (%DRIFT)     AREA    (IN)

   --------------------------------------------------------------------

   .125(   .245)   3  45      35.0  244.0   AERIAL(16.0)  87.0    .0

   FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

   --------------------------------------------------------------------

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)  RAIN/RUNOFF  (RESERVOIR)  (RES.-EFF)   (RESER.)   (RESER.)

   --------------------------------------------------------------------

     61.00        2          N/A       .00-     .00   292.00    292.00

   UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0  JAN 1, 2007

   --------------------------------------------------------------------

        PEAK DAY  (ACUTE)      ANNUAL AVERAGE (CHRONIC)

          CONCENTRATION             CONCENTRATION

   --------------------------------------------------------------------

9.715

Sulfometuron methyl total residues, Single application, Aerial.

RUN No.  12 FOR Sulfometuron Tot ON   Forest        * INPUT VALUES *

   --------------------------------------------------------------------

    RATE (#/AC)   No.APPS &   SOIL  SOLUBIL  APPL TYPE  %CROPPED INCORP

     ONE(MULT)    INTERVAL    Koc   (PPM )   (%DRIFT)     AREA    (IN)

   --------------------------------------------------------------------

   .375(   .375)   1   1      35.0  244.0   AERIAL(16.0)  87.0    .0

   FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

   --------------------------------------------------------------------

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)  RAIN/RUNOFF  (RESERVOIR)  (RES.-EFF)   (RESER.)   (RESER.)

   --------------------------------------------------------------------

    136.00        2          N/A       .00-     .00      .00       .00

   UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0  JAN 1, 2007

   --------------------------------------------------------------------

        PEAK DAY  (ACUTE)      ANNUAL AVERAGE (CHRONIC)

          CONCENTRATION             CONCENTRATION

   --------------------------------------------------------------------

             32.354                     21.819

Sulfometuron methyl total residues, 2 applications, 30 day interval,
Aerial.

   RUN No.  13 FOR Sulfometuron Tot ON   Forest        * INPUT VALUES *

   --------------------------------------------------------------------

    RATE (#/AC)   No.APPS &   SOIL  SOLUBIL  APPL TYPE  %CROPPED INCORP

     ONE(MULT)    INTERVAL    Koc   (PPM )   (%DRIFT)     AREA    (IN)

   --------------------------------------------------------------------

   .188(   .348)   2  30      35.0  244.0   AERIAL(16.0)  87.0    .0

   FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

   --------------------------------------------------------------------

   METABOLIC  DAYS UNTIL  HYDROLYSIS   PHOTOLYSIS   METABOLIC  COMBINED

    (FIELD)  RAIN/RUNOFF  (RESERVOIR)  (RES.-EFF)   (RESER.)   (RESER.)

   --------------------------------------------------------------------

    136.00        2          N/A       .00-     .00      .00       .00

   UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0  JAN 1, 2007

   --------------------------------------------------------------------

        PEAK DAY  (ACUTE)      ANNUAL AVERAGE (CHRONIC)

          CONCENTRATION             CONCENTRATION

   --------------------------------------------------------------------

             30.208                     20.375

SCI-GROW Modeling Input and Output Files

                   SCIGROW VERSION 2.3

            ENVIRONMENTAL FATE AND EFFECTS DIVISION

                 OFFICE OF PESTICIDE PROGRAMS

             U.S. ENVIRONMENTAL PROTECTION AGENCY

                        SCREENING MODEL

                FOR AQUATIC PESTICIDE EXPOSURE

Parent Compound:

SciGrow version 2.3

 chemical:Sulfometuron Total Resides

 time is 10/31/2007  12:30:46

 -----------------------------------------------------------------------
-

  Application      Number of       Total Use    Koc      Soil Aerobic

  rate (lb/acre)  applications   (lb/acre/yr)  (ml/g)   metabolism
(days)

 -----------------------------------------------------------------------
-

      0.375           1.0           0.375      7.34E+01       55.2

 -----------------------------------------------------------------------
-

 groundwater screening cond (ppb) =   3.29E-01

 ***********************************************************************
*

Total Residues:

 SciGrow version 2.3

 chemical:Sulfometuron Total Residues

 time is 10/ 4/2007  14:16:15

 -----------------------------------------------------------------------
-

  Application      Number of       Total Use    Koc      Soil Aerobic

  rate (lb/acre)  applications   (lb/acre/yr)  (ml/g)   metabolism
(days)

 -----------------------------------------------------------------------
-

      0.375           1.0           0.375      7.34E+01      136.0

 -----------------------------------------------------------------------
-

 groundwater screening cond (ppb) =   1.13E+00

 ***********************************************************************
*

  Weber, J.B., G.G. Wilkersona and C.F. Reinhardt. 2004 Calculating
pesticide sorption coefficients (Kd) using selected soil properties.
Chemosphere 55:157–166

  Battaglin, WA, Furlongb, ET,  Burkhardt, MR, Peter, CJ. 2000.
Occurrence of sulfonylurea, sulfonamide, imidazolinone, and other
herbicides in rivers, reservoirs and ground water in the Midwestern
United States. Sci. Tot. Environ. 248: 123-133

  Blomquist, J.D., Denis, J.M., Hetrick, J.A., Jones, R.D., and
Birchfield, N.B. (2001) Pesticides in selected water-supply reservoirs
and finished drinking water, 1999-2000; summary of results from a pilot
monitoring program: U.S. Geological Survey Open-File Report 01-0456, 65
p.

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