UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460 OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES Date: June 08, 2004 MEMORANDUM SUBJECT: OCCUPATIONAL AND RESIDENTIAL EXPOSURE ASSESSMENT AND RECOMMENDATIONS FOR THE REREGISTRATION ELIGIBILITY DECISION DOCUMENT FOR DIMETHIPIN FROM: Seyed Tadayon, Chemist Reregistration Branch III Health Effect Division ( 7509C)

THRU: Steve Weiss, Industrial Hygienist Reregistration Branch III Health Effects Division ( 7509C)

TO: Susan Stanton, Risk Assessor Reregistration Branch III Health Effects Division ( 7509C)

Please find the review of dimethipin. DP Barcode: D332596 PC Codes: 118901 EPA Reg Nos: 400 155, 400 398, 400 432, 400 505, WA98000800 EPA MRID No: NA LUIS Report: 05/ 20/ 2002 PHED: Yes, Version 1.1 2 CONTENTS EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.0 BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.1 Summary of Toxicity Concerns Relating to Agricultural Exposures . . . . . . . . . . . . 5 1.2 Summary of Use Pattern and Formulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3 Method and Types of Equipment Used for Mixing/ Loading/ Applying . . . . . . . . . . 7 1.4 Incident Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.0 OCCUPATIONAL EXPOSURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1 Handler Exposures & Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1.1 Summary of Uncertainties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1.2 Calculations of Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Risk From Handler Exposures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2.1 Risk From Handler Exposures . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2.2 Summary of Handler Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.0 POSTAPPLICATION EXPOSURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 APPENDIX A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3 EXECUTIVE SUMMARY This document addresses the exposures and risks associated with the use of the dimethipin, that occur through non dietary exposure. Non dietary exposures can occur as a result of handling dimethipin or by entering areas that have been previously treated with dimethipin. Exposures can occur as a part of one's job or through uses of dimethipin. There are no residential uses for dimethipin.

Dimethipin, [ 2, 3 dihydro 5,6 dimethyl 1,4 dithi ine 1,1,4,4 tetraoxide] is a defoliant herbicide. Defoliants, desiccants, and growth regulators are chemicals used in agricultural production to accelerate the preparation of crops for mechanical harvest. Dimethipin primarily is designed to inflict sufficient injury to the leaf to upset the hormone balance at the abscission zone and allow enzymes to begin the abscission ( i. e. fall off) process.

The agricultural use sites referenced on dimethipin labels are apple and cotton. A wide variety of application techniques have been identified that could potentially be used to apply dimethipin. These methods include high pressure handwand, groundboom sprayers and fixedwing aircraft.

Dimethipin is formulated as a manufacturing product ( 98.0% active ingredient), two flowable concentrate formulations ( 48.0% active ingredient) and one emulsifiable concentrate formulation ( 32.7 % active ingredient).

Hazard Identification This risk assessment incorporates the toxicological endpoints of concern identified by risk assessment team. No dermal hazard end point was identified, therefore, no quantification is required. Systemic toxicity was not seen at the limit dose in a dermal toxicity rat study. Therefore no short intermediate or long term occupational or residential dermal endpoint of concern was identified.

The occupational short term inhalation endpoint of concern was based on the maternal NOAEL of 20 mg/ kg/ day identified in an oral developmental rabbit study. The maternal LOAEL of 40 mg/ kg/ day was based on decreased body weight gain and intermediate term inhalation Endpoint of concern was based on the 2 generation reproduction study in the rat with a parental systemic NOAEL of 11.8 mg/ kg/ day ( F0 and F1 females). The LOAEL for F0 and F1 females ( 31.2 120.3 mg/ kg/ day) was based on decreased body weights and body weight gains. Based on use pattern, no long term inhalation exposure is anticipated.

Dimethipin has been classified as a Group C ( possible human) carcinogen by the Toxicology Peer Review Committee. The classification was based on evidence of lung adenomas and carcinomas in male CD 1 mouse. The Committee concluded that the rat study was not conducted at a high enough dose, and recommended that a new study be conducted. The results 4 of the new study indicated no evidence of carcinogenicity in the rat. Calculation of a Q 1* was not recommended for dimethipin.

The Agency's level of concern for risks ( i. e., target level for MOEs or Margins of Exposure) is defined by the uncertainty factors that are applied to the assessment. The Agency applies a factor of 100 to account for inter species extrapolation to humans from the animal test species and to account for intra species sensitivity.

Occupational Handler Risks Short and intermediate term inhalation risks to occupational handlers at baseline Personal Protective Equipment ( PPE) ( i. e., no respirator) are below the Agency's level of Concern ( i. e., MOE

100). EPA has insufficient data to assess exposures to pilots in open cockpits. Inhalation risks to pilots in enclosed cockpits ( i. e., engineering control scenario) were also below the Agency's level of Concern ( i. e., MOE

100).

Short and intermediate term dermal risks were not assessed for occupational handlers, since no short or intermediate term dermal endpoint was identified.

HED has determined that there are potential exposures to mixers, loaders, applicators, and other handlers during usual use patterns associated with dimethipin. Six major exposure scenarios were identified for dimethipin, including mixing, loading, and applying using ground spray and aerial application.

The results of the short and intermediate term inhalation handler assessments indicate that all potential exposure scenarios provide at least one application rate with a total MOE( s) greater than 100 at either the baseline ( i. e., no respirator) or using engineering controls ( i. e., closed systems). The MOEs for all the scenarios range from 880 to 1,300,000.

EPA did not quantify occupational postapplication risks to agricultural workers following treatments to cotton or apple, since no dermal endpoints of concern were identified. The acute toxicity classification for dermal irritation of dimethipin is tox category III which requires a 12 hour REI.

On the list of the top 200 chemicals for which NPIC received calls from 1984 1991 inclusively, dimethipin was not reported to be involved in human incidents relatively few incidents of illness have been reported due to dimethipin. 5 1.0 BACKGROUND Purpose In this document, which is for use in EPA's development of the dimethipin. Reregistration Eligibility Decision Document ( RED), EPA presents the results of its review of the potential human health effects of occupational exposure to dimethipin.

Criteria for Conducting Exposure Assessments An occupational and/ or residential exposure assessment is required for an active ingredient if ( 1) certain toxicological criteria are triggered and ( 2) there is potential exposure to handlers ( mixers, loaders, applicators, etc.) during use or to persons entering treated sites after application is complete. For dimethipin, both criteria are met.

1.1 Summary of Toxicity Concerns Relating to Agricultural Exposures The acute toxicity data base for dimethipin is considered complete for acute oral, acute dermal, acute inhalation, dermal and eye irritation, and dermal sensitization. Dimethipin has a moderate order of acute toxicity via the oral ( Category II) and inhalation routes ( Category II). It has a low order of acute toxicity via the dermal ( Category III) route of exposure. It is not an eye or skin irritant, or a dermal sensitizer. The acute toxicity data for dimethipin is summarized below in Table 1.

Table1. Acute Toxicity Profile for Dimethipin Guideline Number Study Type MRID Number Results Toxicity Category 870.1100( § 81 1) Acute Oral 42429601 LD50 = 458 mg/ kg (

) LD50 = 546 mg/ kg (  ) II 870.1200 ( § 81 2) Acute Dermal 42429602 LD50 > 5000 mg/ kg III 870.1300 ( § 81 3) Acute Inhalation 42429603 LC50 = 1.2 mg/ L. II 870.2400 ( § 81 4) Primary Eye Irritation 00070237 non irritant IV 870.2500 ( § 81 5) Primary Dermal Irritation 42429604 non irritant IV 870.2600 ( § 81 6) Dermal Sensitization 42429605 not a sensitizer

Other Endpoints of Concern The dimethipin risk assessment team, identified toxicological endpoints of concern for dimethipin.

All calculations completed in this document are based on the most current toxicity 6 information available for dimethipin. The endpoints that were used to complete this assessment are summarized below in Table 2.

Table2: Summary of Toxicological Doses and Endpoints for Dimethipin for Use in Human Risk Assessment Exposure Scenario Dose ( mg/ kg/ day)

UF / MOE Hazard Based Special FQPA Safety Factor Endpoint for Risk Assessment Incidental Oral Short and Intermediate Term Not required  no residential uses. Not required

no residential uses. Not required  no residential uses.

Non Dietary Risk Assessments Dermal Short and Intermediate Term N/ A N/ A No hazard was identified therefore no quantification is required. Systemic toxicity not seen at the limit dose in a Dermal Toxicity Study. Additionally, there are no developmental concerns.

Dermal Long Term N/ A N/ A Based on use pattern, no exposure is anticipated.

Inhalation Short Term ( 1  30 days) NOAEL = 20 mg/ kg/ day Developmental Study in the Rabbit LOAEL = 40 mg/ kg/ day, based on decreased body weight gain. Occupational MOE= 100 N/ A Inhalation Intermediate Term ( 1  6 Months) NOAEL = 11.8 mg/ kg/ day Two generation reproduction study in the rat LOAEL = 31.2 120.3 mg/ kg/ day, based on decreased body weight/ body weight gain in F0 & F1 females.

Occupational MOE = 100 N/ A Inhalation Long Term (> 6 Months) NA NA Based on use pattern, no exposure is anticipated.

Cancer Classification: Class C ( possible carcinogen) calculation of a q1* was not recommended.

1.2 Summary of Use Patterns and Formulations At this time, products containing dimethipin are intended for occupational use only.

Type of pesticide Dimethipin is a herbicide used for cotton and non bearing apple defoliation. Defoliation is a critical step in cotton production and involves removing leaves and preparing the crop for mechanical harvest. Leaf removal facilitates harvest and allows for more efficient and faster picker operation, quicker drying of seed cotton, straightening of lodged plants, retardation of boll rot and faster opening of green bolls. In many cases, chemicals that hasten the opening of green bolls and inhibit juvenile regrowth are included with a defoliant ( Leafless ® ) . 7 Formulation types and percent active ingredient Dimethipin is formulated as a manufacturing product ( 98.0% active ingredient), two Flowable concentrate formulation ( 48.0% active ingredient) and one emulsifiable concentrate formulation ( 32.7 % active ingredient)

Registered use sites, application rates and frequency of application Dimethipin is applied as a pre harvest, foliar and after boil opening on cotton. It can also be used to defoliate non bearing apple nursery stock prior to digging or harvesting. Dimethipin can be applied at a minimum application rate of 0.077 to a maximum application rate of 0.56 pounds active ingredient per acre.

Table 3 represents information on registered use sites, products name, application rates, percent active ingredient and frequency of application per growing season for dimethipin. Application rate covers various type of equipment used to apply dimethipin.

Table 3: Use Patterns, Application Rate, and Frequency of Application for Dimethipin Reg No ai % Product Name Crop Type Max Appl rate lb ai/ A No of Appls per/ year 400 505 32.7 Leafless cotton ( after boll opening) 0.31 NS 400 155 48.0 Harvade 5F cotton ( foliar) 0.31 400 398 22.4 Harvade 25F cotton ( preharvest) 0.56 WA 980008 48.0 Harvade 5F non bearing apple ( foliar) 0.077 400 432 98.00 Harvade Technical 1.3 Methods and Types of Equipment Used for Mixing/ Loading/ Applying The following use patterns are associated with the application equipment:

groundboom, high pressure handwand and fixed wing aircraft.

1.4 Incident reports On the list of the top 200 chemicals for which NPIC received calls from 1984 1991 inclusively, dimethipin was not reported to be involved in human incidents. Relatively few incidents of illness have been reported due to dimethipin.

2.0 OCCUPATIONAL EXPOSURES 8 2.1 Handler Exposures & Assumptions Handler Exposure Scenarios Exposure scenarios can be thought of as ways of categorizing the kinds of exposures that occur related to the use of a chemical. The use of scenarios as a basis for the exposure assessment is described in the U. S. EPA Guidelines For Exposure Assessment ( U. S. EPA; Federal Register Volume 57, Number 104; May 29, 1992).

HED uses the term " Handlers" to describe those individuals who are involved in the pesticide application process. HED believes that there are distinct job functions or tasks related to applications and that exposures can vary depending on the specifics of each task. Job requirements ( e. g., amount of chemical to be used in an application), the kinds of equipment used, the crop or target being treated, and the circumstances of the user ( e. g., the level of protection used by an applicator) can cause exposure levels to differ in a manner specific to each scenario.

HED has developed a series of general descriptions for tasks that are associated with pesticide applications. Tasks associated with pesticide use ( i. e., for " handlers") can generally be categorized using one of the following terms:

 Occupational Mixer/ loaders: these individuals perform tasks in preparation for an application. For example, they would prepare dilute spray solutions or transfer dilute spray solutions into application equipment such as a groundboom tractor.

 Occupational Applicators: these individuals operate application equipment during the application of dimethipin to registered sites. These individuals can make applications using equipment such as groundboom sprayers.

HED has determined that there are potential exposures to mixers, loaders, applicators, or other handlers during usual use patterns associated with dimethipin. Based on the use patterns and potential exposures described above, 7 major exposure scenarios are identified in this document to represent the extent of dimethipin uses These scenarios include: ( 1) mixing/ loading liquids for aerial application, ( 2) mixing/ loading liquids for groundboom application, ( 3) mixing/ loading liquids for high pressure handwand, ( 4) sprays for aerial application, ( 5) sprays for groundboom application, ( 6) spray for High pressure handwand application and ( 7) flagging for sprays application. 9 2.1.1 Summary of Uncertainties The handler exposure assessments encompass use of dimethipin throughout the country. It is difficult to assess all of the " typical" uses ( i. e., actual or predominate application rates and farm sizes), and therefore, an assessment has been developed that is believed to be realistic and yet provides a reasonable certainty that the exposures are not underestimated. The assumptions and uncertainties are identified below to be used in risk management decisions:

 Application Rates: The application rates are the maximum allowable that were identified on the available product labels.

 Amount Handled: The daily acres treated are HED standard values ( see Table 4).

The values for groundboom applications in agriculture vary. Groundboom applications in an agricultural setting for cotton are based on an 200 acre day because the Agency believes it would take 8 hours to complete that type of application with common equipment and that acreage estimate for various crops is reasonable. For application with fixed wing aircraft 1200 acre per day was used. For application with high pressure handwand 1000 gallons / day used.

Table 4 presents the exposure scenarios, application rates, and area ( i. e., acres or gals) potentially treated that have been used in the exposure calculations. Dimethipin labels include a multitude of uses and a range of application rates.

Chemical specific data for assessing human exposures during pesticide handling activities were not submitted to the Agency in support of the reregistration of dimethipin. Consequently it is the policy of the HED to use data from the Pesticide Handlers Exposure Database ( PHED) Version 1.1 to assess handler exposures for regulatory actions when chemical specific monitoring data are not available.

PHED was designed by a task force of representatives from the U. S. EPA, Health Canada, the California Department of Pesticide regulation, and member companies of the American Crop Protection Association. PHED is a software system consisting of two parts  a database of measured exposure values for workers involved in the handling of pesticides under actual field conditions and a set of computer algorithms used to subset and statistically summarize the selected data. Currently, the database contains values for over 1,700 monitored individuals ( i. e., replicates)

Users select criteria to subset the PHED database to reflect the exposure scenario being evaluated. The subsetting algorithms in PHED are based on the central assumption that the magnitude of handler exposures to pesticides are primarily a function of activity ( e. g., mixing/ loading, applying), formulation type ( e. g., liquid), application method ( e. g., groundboom), and clothing scenarios ( e. g., gloves). 10 Once the data for a given exposure scenario have been selected, the data are normalized ( i. e., divided by) by the amount of pesticide handled resulting in standard unit exposures ( milligrams of exposure per pound of active ingredient handled). Following normalization, the data are statistically summarized. The distribution of exposure values for each body part ( e. g., chest upper arm) is categorized as normal, lognormal, or " other" ( i. e., neither normal nor lognormal). A central tendency value is then selected from the distribution of the exposure values for each body part. These values are the arithmetic mean for normal distributions, the geometric mean for lognormal distributions, and the median for all " other" distributions. Once selected, the central tendency values for each body part are composited into a " best fit" exposure value representing the entire body.

The unit exposure values calculated by PHED generally range from the geometric mean to the median of the selected data set. To add consistency and quality control to the values produced from this system, the PHED Task Force has evaluated all data within the system and has developed a set of grading criteria to characterize the quality of the original study data. The assessment of data quality is based on the number of observations and the available quality control data. These evaluation criteria and the caveats specific to each exposure scenario are summarized in Table A3. While data from PHED provide the best available information on handler exposures, it should be noted that some aspects of the included studies ( e. g., duration, acres treated, pounds of active ingredient handled) may not accurately represent labeled uses in all cases. HED has developed a series of tables of standard unit exposure values for many occupational scenarios that can be utilized to ensure consistency in exposure assessments.

Table 4: Exposure Variables for Uses of Dimethipin Exposure Scenario ( Scenario #) Crop Type Application Rates ( lb ai/ acre or gal ) a Daily Acres or gals Treatedb Mixer/ Loader Exposure mixing/ loading liquids for aerial application ( 1) Cotton 0.56 1200 mixing/ loading liquids for groundboom application ( 2) 200 mixing/ loading liquids for High pressure Hand Wand ( 3) Apple 0.00077/ gal 1000 gals Applicator sprays for aerial application ( 4) Cotton 0.56 1200 sprays for groundboom application ( 5) 200 Spray for High pressure Hand Wand application ( 6) Apple 0.00077/ gal 1000 gals Flagger flagging for sprays application ( 7) Cotton 0.56 350 a Application rates are the maximum found on dimethipin labels b Daily acres or gallons treated are based on HED's estimates of acreage that would be reasonably expected to be treated in a single day for each exposure scenario of concern. 11 2.1.2 Calculation of Exposure Daily Exposure: The daily inhalation exposure, daily dose and hence the inhalation risks, to handlers were calculated as described below. The first step was to calculate daily exposure ( inhalation) using the following formula:

Where: Daily Inhalation Exposure ( mg ai/ day) =

Unit Exposure ( mg ai/ lb ai) x Application Rate ( lb ai/ A) x Daily Area Treated ( A)

Daily Exposure = Amount that is inhaled, also referred to as potential dose ( mg ai/ day);

Unit Exposure = Normalized exposure value derived from August 1998 PHED Surrogate Exposure Table.

Application Rate = Normalized application rate based on a logical unit treatment, such as acres. Maximum value is used ( lb ai/ A), and Daily Area Treated = Normalized application area based on a logical unit treatment such as acres ( A/ day).

These calculations of potential daily inhalation exposure to dimethipin by handlers are used to calculate the absorbed doses and total risk to those handlers.

2.2 Risk from Handler exposure 2.2.1 Calculation of Daily Dose Using the daily inhalation exposure scenarios identified in the exposure section, EPA calculated the potential risk to persons from handler inhalation exposures to dimethipin.

The daily inhalation doses were calculated using a 60 ( developmental effect) kg body weight using the following formulas:

Average Daily inhalation dose ( mg/ kg/ day) = daily inhalation exposure( mg ai/ day)/ body weight( kg) x absorption factor( 100%)

Daily Exposure = Amount that is available for inhalation, also referred to as potential dose ( mg ai/ day);

Average Daily Dose = The amount as absorbed dose received from exposure to a pesticide in a given scenario ( mg pesticide active ingredient/ kg body weight/ day, also referred to as ADD);

Absorption Factor = A measure of the flux or amount of chemical that crosses a biological boundary (% of the total available absorbed); and Body Weight = Body weight determined to represent the population of interest 12 ( female) in a risk assessment ( 60kg).

The MOEs were calculated using the following formulas:

Inhalation MOE= Average Daily Inhalation Dose ( mg/ kg/ day)/ Inhalation NOAEL( mg/ kg/ day)

MOE = Margin of exposure, value used by the Agency to represent risk or how close a chemical exposure is to being a concern ( unitless);

ADD = ( Average Daily Dose) or the amount as absorbed dose received from exposure to a pesticide in a given scenario ( mg pesticide active ingredient/ kg body weight/ day); and NOAEL = Dose level in a toxicity study, where no observed adverse effects occurred ( NOAEL) in the study or the lowest dose level where an adverse effect occurred.

Handler exposure assessments are completed by EPA using a baseline exposure scenario and, if required, increasing levels of risk mitigation ( PPE and engineering controls) to achieve a margin of exposure of 100 for dermal and inhalation exposure. Appendix A presents the shortterm and intermediate term MOE calculations for baseline exposure and engineering control for fixed wing aircraft using data from PHED.

EPA calculated the baseline MOE ( short term and intermediate term) for each of the exposure scenarios using the baseline attire ( no respirator).

If the baseline short term or intermediate term MOE calculated using this baseline PPE was 100 or greater ( since the NOAEL is based on data from animal studies) for an exposure scenario, then no further calculations were made.

Because of the insufficient number of data points for fixed wing, open cockpit aircraft in the PHED, these data should not be used either as a subset, or in combination with data from fixed wing, closed cockpit aircraft. Therefore HED calculated the short term and intermediateterm inhalation MOE for fixed wing aircraft scenario with closed cockpit ( i. e., engineering control.)

2.2.2 Summary of Handler Risks Table 5 summarizes the numeric MOE values for both the short and intermediate term inhalation exposure durations. The MOEs are presented for baseline and engineering controls ( engineering controls assessment is for fixed wing aircraft only).

The results of the short and intermediate term handler inhalation assessments indicate that 13 all potential exposure scenarios provide MOE( s) greater than 100 at either the baseline ( i. e., no respirator) using open systems or using engineering controls ( i. e., closed systems for fixed wing aircraft). In total, 14 MOEs were calculated for the maximum application rate.

Table 5: Summary of Occupational Handler Risk for Dimethipin Exposure Scenario ( Scenario #) Crop Application Rate lb ai/ A Daily Area Treated A or gal/ day Short Term Inhalation MOE Intermediate Term Inhalation MOE Mixer/ Loader Mixing/ Loading Liquids for Aerial application ( 1) Cotton 0.56 1200 1500 880 Mixing/ Loading Liquids for Groundboom application ( 2) 200 8900 5300 mixing/ loading liquids for Highpressure Hand Wand ( 3) Apple 0.00077/ gal 1000 gals 1300000 770000 Applicator Sprays for Aerial application ( 4) Cotton 0.56 1200 26000 ( engineerin g control) 15000 ( engineering control)

Sprays for Groundboom application ( 5) 200 14000 8500 Spray for High pressure Hand Wand application ( 6) Apple 0.00077/ gal 1000 gals 20000 12000 Flagger Flagging for Sprays application ( 7) Cotton 0.56 350 17000 10000 14 3.0 POSTAPPLICATION EXPOSURES EPA did not assess occupational postapplication risks to agricultural workers following treatments to cotton or non bearing apple nursery stock., since no short or intermediate term dermal endpoint of concern was identified and long term dermal exposures are not expected for tasks involving cotton or apple use patterns. The toxicity categories of the active ingredient for acute dermal, eye irritation, and skin irritation potential are used to determine the interim REI ( Restricted entry Intervals). The acute toxicity classification for dermal irritation of dimethipin is tox category III which requires a 12 hour REI. 15 APPENDIX A SHORT TERM AND INTERMEDIATE TERM HANDLER EXPOSURE RISK TABLES A1 THROUGH A3 16 Table A1: Short Term Inhalation risk for occupational Handler with Dimethipin at Baseline Exposure Scenario ( Scenario #) Inhalation Unit Exposure ( Ug/ lb ai) 1 Crop2 Application Rate3 lb ai/ A or gal Daily Area Treated4 A or gals/ day Inhalation Dose ( mg/ kg/ day) 5 Inhalation MOE6 Mixer/ Loader Mixing/ Loading Liquids for Aerial application ( 1) 1.2 Cotton 0.56 1200 0.013 1500 Mixing/ Loading Liquids for Groundboom application ( 2) 200 0.0022 8900 mixing/ loading liquids for High pressure Hand Wand ( 3) 1.2 Apple 0.00077 / gal 1000 gals 0.000015 1300000 Applicator Sprays for Aerial application ( 4) 0.068 ( engineering control) Cotton 0.56 1200 0.00076 ( engineering control) 26000 ( engineering control)

Sprays for Groundboom application ( 5) 0.74 200 0.0014 14000 Spray for High pressure Hand Wand application ( 6) 79 Apple 0.00077 / gal 1000 gals 0.0010 20000 Flagger Flagging for Sprays application ( 7) 0.35 Cotton 0.56 350 0.0011 17000 1Baseline or Engineering Control inhalation unit exposures represent no respirator. Values are reported in the PHED Surrogate Exposure Guide dated August 1998 2Crops and use patterns are from Dimethipin labels and LUIS report 3Application rates are based on maximum values found in various sources including LUIS and various labels. Application rates upon which the analysis is based are presented as lb ai/ A or lb ai/ gal.

4Amount treated is based on the area that can be reasonably applied in a single day for each exposure scenario of concern based on the application method and formulation/ packaging type. ( Standard EPA/ OPP/ HED values).

5Inhalation dose ( mg/ kg/ day) = [ unit exposure ( ug/ lb ai) * 0.001 mg/ g unit conversion * Inhalation absorption ( 100%) * Application rate ( lb ai/ acre or lb ai/ gal ) * Daily area treated ( acres or gals )] / Body weight ( 60 kg).

6Inhalation MOE = inhalation NOAEL ( 20 mg/ kg/ day) / Daily Inhalation Dose. Target Inhalation MOE is 100. 17 Table A2: Intermediate Term Inhalation risk for occupational Handler with Dimethipin Exposure Scenario ( Scenario #) Inhalation Unit Exposure ( Ug/ lb ai) 1 Crop2 Applica tion Rate3 lb ai/ A or gals Daily Area Treated 4 A or gals/ day Inhalatio n Dose ( mg/ kg/ d ay) 5 Inhalati on MOE6 Mixer/ Loader Mixing/ Loading Liquids for Aerial application ( 1) 1.2 Cotton 0.56 1200 0.013 880 Mixing/ Loading Liquids for Groundboom application ( 2) 200 0.0022 5300 mixing/ loading liquids for Highpressure Hand Wand ( 3) 1.2 Apple 0.00077/ gal 1000 gals 0.000015 770000 Applicator Sprays for Aerial application ( 4) 0.068 ( engineering control) Cotton 0.56 1200 0.00076 ( engineer ing control) 15000 ( enginee ring control)

Sprays for Groundboom application ( 5) 0.74 200 0.0014 8500 Spray for High pressure Hand Wand application ( 6) 79 Apple 0.00077/ gal 1000 gals 0.0010 12000 Flagger Flagging for Sprays application ( 7) 0.35 Cotton 0.56 350 0.0011 10000 1Baseline or Engineering Control inhalation unit exposures represent no respirator. Values are reported in the PHED Surrogate Exposure Guide dated August 1998 2Crops and use patterns are from Dimethipin labels and LUIS report 3Application rates are based on maximum values found in various sources including LUIS and various labels. Application rates upon which the analysis is based are presented as lb ai/ Aor gal.

4Amount treated is based on the area that can be reasonably applied in a single day for each exposure scenario of concern based on the application method and formulation/ packaging type. ( Standard EPA/ OPP/ HED values).

5Inhalation dose ( mg/ kg/ day) = [ unit exposure ( ug/ lb ai) * 0.001 mg/ g unit conversion * Inhalation absorption ( 100%) * Application rate ( lb ai/ acre or gals ) * Daily area treated ( acres or gals )] / Body weight ( 60 kg).

6Inhalation MOE = inhalation NOAEL ( 11.8 mg/ kg/ day) / Daily Inhalation Dose. Target Inhalation MOE is 100 18 Table A3: Sources of Exposure Data Used In The Short and Intermediate Term Occupational Dimethipin Handler Exposure And Risk calculation Exposure Scenario ( Number) Data Source Standard Assumptions ( 8 hr work day) Comments Mixer/ Loader Descriptors Mixing/ Loading Liquid Formulations ( 1 through 3) PHED V1.1 Aerial: 1200 acres for cotton Groundboom: 200 acres High Pressure Handwand: 1000 gals Baseline: Inhalation = 85 replicates. High confidence in inhalation data.

Applying Descriptors Applying Sprays with a Fixed wing Aircraft ( 4) PHED V1.1 1200 acres Engineering Controls: inhalation = ABC grade. Inhalation = 23 replicates. Medium confidence in inhalation data. No protection factor was needed to define the unit exposure value. EPA has no data for this scenario, other than enclosed cockpits B the engineering control.

Applying Sprays with a Groundboom Sprayer ( 5) PHED V1.1 200 acres Baseline: Inhalation = acceptable grades. inhalation = 22 replicates.

High confidence in inhalation data.

Liquids Using a High Pressure Handwand ( 6) PHED V1.1 1,000 gallons Baseline: Inhalation ( 13 replicates) exposure values are based on A grade data.

Low confidence in inhalation data.

Flagging Descriptors Flagging Aerial Spray Applications ( 6) PHED V1.1 350 acres Baseline: inhalation = acceptable grades. inhalation = 28 replicates.

High confidence in inhalation data.

a All Standard Assumptions are based on a typical work day ( the components that involve pesticide use) as estimated by HED.

b All handler exposure assessments in this document are based on the " Best Available" data as defined by the PHED SOP for meeting Subdivision U Guidelines ( i. e., completing exposure assessments). Best available grades are assigned to data as follows: matrices with A and B grade data ( i. e., Acceptable Grade Data) and a minimum of 15 replicates; if not available, then grades A, B and C data and a minimum of 15 replicates; if not available, then all data regardless of the quality ( i. e., All Grade Data) and number of replicates. Generic data confidence categories are assigned as follows:

High = grades A and B and 15 or more replicates per body part Medium = grades A, B, and C and 15 or more replicates per body part Low = grades A, B, C, D and E or any combination of grades with less than 15 replicates.


[Federal Register Volume 85, Number 173 (Friday, September 4, 2020)]
[Rules and Regulations]
[Pages 55169-55171]
[FR Doc No: 2020-19581]

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Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0327; Product Identifier 2020-NM-033-AD; Amendment
39-21228; AD 2020-18-07]
RIN 2120-AA64

Airworthiness Directives; Airbus SAS Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2016-18-
09, which applied to certain Airbus SAS Model A318, A319, and A320
series airplanes. AD 2016-18-09 required repetitive detailed
inspections for damage on the fuselage skin at certain frames, and
applicable related investigative and corrective actions. This AD
continues to require repetitive inspections of the fuselage skin for
chafing damage at certain frames using a new inspection process, and
corrective actions if necessary; as specified in a European Union
Aviation Safety Agency (EASA) AD, which is incorporated by reference.
This AD was prompted by reports of additional chafing of the forward
fuselage found underneath the fairing structure. Investigation revealed
the cause as contact between the belly fairing nut plate and the
fuselage. The FAA is issuing this AD to address the unsafe condition on
these products.

DATES: This AD is effective October 9, 2020.
    The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of October 9,
2020.

ADDRESSES: For material incorporated by reference (IBR) in this AD,
contact the EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany;
telephone +49 221 8999 000; email<EMAIL_ADDRESS>internet
www.easa.europa.eu. You may find this IBR material on the EASA website
at https://ad.easa.europa.eu. You may view this IBR material at the
FAA, Airworthiness Products Section, Operational Safety Branch, 2200
South 216th St., Des Moines, WA. For information on the availability of
this material at the FAA, call<PHONE_NUMBER>. It is also available in
the AD docket on the internet at https://www.regulations.gov by
searching for and locating Docket No. FAA-2020-0327.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0327; or in person at Docket Operations between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays. The AD docket contains
this final rule, any comments received, and other information. The
address for Docket Operations is U.S. Department of Transportation,
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200
New Jersey Avenue SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Sanjay Ralhan, Aerospace Engineer,
Large Aircraft Section, International Validation Branch, FAA, 2200
South 216th St., Des Moines, WA 98198; telephone and fax<PHONE_NUMBER>;
email<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Discussion

    The EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2020-0030, dated February 18, 2020
(``EASA AD 2020-0030'') (also referred to as the Mandatory Continuing
Airworthiness Information, or ``the MCAI''), to correct an unsafe
condition for certain Airbus SAS Model A318 series airplanes; Model
A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes; and
Model A320-211, -212, -214, -215, -216, -231, -232, and -233 airplanes.
Model A320-215 airplanes are not certificated by the FAA and are not
included on the U.S. type certificate data sheet; therefore, this AD
does not include those airplanes in the applicability. EASA AD 2020-
0030 supersedes EASA AD 2014-0259 (which corresponds to FAA AD 2016-18-
09, Amendment 39-18639 (81 FR 61993, September 8, 2016) (AD 2016-18-
09)).
    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2016-18-09. AD 2016-18-09 applied to
certain Airbus SAS Model A318, A319, and A320 series airplanes. The
NPRM published in the Federal Register on April 10, 2020 (85 FR 20203).
The NPRM was prompted by reports of additional chafing of the forward
fuselage found underneath the fairing structure. Investigation revealed
the cause as contact between the belly fairing nut plate and the
fuselage. The NPRM proposed to continue to require repetitive
inspections of the fuselage skin for chafing damage at certain frames
using a new inspection process, and corrective actions if necessary, as
specified in an EASA AD.
    The FAA is issuing this AD to address damage to the fuselage skin,
which could lead to crack initiation and propagation, possibly
resulting in reduced structural integrity of the fuselage. See the MCAI
for additional background information.

Comments

    The FAA gave the public the opportunity to participate in
developing this final rule. The following presents the comment received
on the NPRM and the FAA's response to the comment.

Request To Provide Clarification That Inspection Includes Existing
Repairs

    United Airlines (UAL) asked that the FAA clarify whether the
proposed inspection of the external skin panel includes existing
repairs. UAL stated that the inspections specified in Airbus Service
Bulletin A320-53-1287 (the appropriate source of service information
for certain actions in AD 2016-18-09, as well as in EASA AD 2020-0030)
continue to involve repair doublers as a result of chafing beyond
allowable skin panel damage. UAL added that clarification regarding
existing repairs is necessary since Airbus Service Bulletin A320-53-
1287 does not include specific instructions to remove any existing
doubler, nor give specific instructions to include existing repairs
during the skin panel inspection. UAL noted that it is not necessary to
remove any reinforcement repair, because the chafing damage from the

fairing panel will cause damage to an external repair before reaching
the original skin panel. UAL stated that it had previously submitted a
similar request for different rulemaking, which was approved; the
phrase ``including previously repaired areas'' was added to AD 2016-18-
09.
    The FAA provides the following clarification. For the reasons
stated by the commenter, we agree to include previously repaired areas
for the inspection required by paragraph (g). The FAA has added
paragraph (h)(5) of this AD to clarify that inspecting previously
repaired areas is included.

Conclusion

    The FAA reviewed the relevant data, considered the comment
received, and determined that air safety and the public interest
require adopting this final rule with the change described previously
and minor editorial changes. The FAA has determined that these minor
changes:
     Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
     Do not add any additional burden upon the public than was
already proposed in the NPRM.
    The FAA also determined that these changes will not increase the
economic burden on any operator or increase the scope of this final
rule.

Related IBR Material Under 1 CFR Part 51

    EASA AD 2020-0030 describes procedures for repetitive inspections
of the fuselage skin for chafing damage at certain frames, and
applicable corrective actions if damage is found. The corrective
actions include a special detailed inspection of external fuselage skin
panel for any cracking, measurement of crack length and remaining
thickness, modification, and repair. EASA AD 2020-0030 also provides an
optional terminating action (modification of the forward belly fairing)
for the repetitive inspections. This material is reasonably available
because the interested parties have access to it through their normal
course of business or by the means identified in the ADDRESSES section.

Costs of Compliance

    The FAA estimates that this AD affects 1,538 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
                                                                                Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Retained actions from AD 2016-18-09...  12 work-hours x $85 per              $90          $1,110      $1,691,800
                                         hour = $1,020.
New proposed actions..................  13 work-hours x $85 per              150           1,255       1,930,190
                                         hour = $1,105.
----------------------------------------------------------------------------------------------------------------

                 Estimated Costs of On-Condition Actions
------------------------------------------------------------------------
                                                             Cost per
               Labor cost                   Parts cost        product
------------------------------------------------------------------------
21 work-hours x $85 per hour = $1,785...          $3,550          $5,335
------------------------------------------------------------------------

                  Estimated Costs for Optional Actions
------------------------------------------------------------------------
                                                             Cost per
               Labor cost                   Parts cost        product
------------------------------------------------------------------------
21 work-hours x $85 per hour = $1,785...          $4,150          $5,935
------------------------------------------------------------------------

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: General requirements.
Under that section, Congress charges the FAA with promoting safe flight
of civil aircraft in air commerce by prescribing regulations for
practices, methods, and procedures the Administrator finds necessary
for safety in air commerce. This regulation is within the scope of that
authority because it addresses an unsafe condition that is likely to
exist or develop on products identified in this rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order
13132. This AD will not have a substantial direct effect on the States,
on the relationship between the national government and the States, or
on the distribution of power and responsibilities among the various
levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by removing Airworthiness Directive (AD)
2016-18-09, Amendment 39-18639 (81 FR 61993, September 8, 2016), and
adding the following new AD:

2020-18-07 Airbus SAS: Amendment 39-21228; Docket No. FAA-2020-0327;
Product Identifier 2020-NM-033-AD.

(a) Effective Date

    This AD is effective October 9, 2020.

(b) Affected ADs

    This AD replaces AD 2016-18-09, Amendment 39-18639 (81 FR 61993,
September 8, 2016) (``AD 2016-18-09'').

(c) Applicability

    This AD applies to Airbus SAS Model airplanes specified in
paragraphs (c)(1) through (3) of this AD, certificated in any
category, as identified in European Union Aviation Safety Agency
(EASA) AD 2020-0030, dated February 18, 2020 (``EASA AD 2020-
0030'').
    (1) Model A318-111, -112, -121, and -122 airplanes.
    (2) Model A319-111, -112, -113, -114, -115, -131, -132, and -133
airplanes.
    (3) Model A320-211, -212, -214, -216, -231, -232, and -233
airplanes.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Reason

    This AD was prompted by reports of additional chafing of the
forward fuselage underneath the fairing structure. Investigation
revealed the cause as contact between the belly fairing nut plate
and the fuselage. The FAA is issuing this AD to address damage to
the fuselage skin, which could lead to crack initiation and
propagation, possibly resulting in reduced structural integrity of
the fuselage.

(f) Compliance

    Comply with this AD within the compliance times specified,
unless already done.

(g) Requirements

    Except as specified in paragraph (h) of this AD: Comply with all
required actions and compliance times specified in, and in
accordance with, EASA AD 2020-0030.

(h) Exceptions to EASA AD 2020-0030

    (1) Where EASA AD 2020-0030 refers to its effective date, this
AD requires using the effective date of this AD.
    (2) The ``Remarks'' section of EASA AD 2020-0030 does not apply
to this AD.
    (3) Where EASA AD 2020-0030 refers to the effective date of EASA
AD 2014-0259, this AD requires using October 13, 2016 (the effective
date of AD 2016-18-09).
    (4) Where EASA AD 2020-0030 refers to doing actions ``in
accordance with the instructions of'' the service information, for
this AD, only use paragraph 3.C., ``Procedure,'' of the service
information.
    (5) Where paragraph (1) of EASA AD 2020-0030 requires
accomplishing a detailed inspection of the affected area (external
fuselage skin panels), for this AD, that inspection also includes
inspecting previously repaired areas.

(i) Other FAA AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager,
Large Aircraft Section, International Validation Branch, FAA, has
the authority to approve AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19,
send your request to your principal inspector or local Flight
Standards District Office, as appropriate. If sending information
directly to the Large Aircraft Section, International Validation
Branch, send it to the attention of the person identified in
paragraph (j) of this AD. Information may be emailed to<EMAIL_ADDRESS>    (i) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
    (ii) AMOCs approved previously for AD 2016-18-09 are approved as
AMOCs for the corresponding provisions of EASA AD 2020-0030 that are
required by paragraph (g) of this AD.
    (2) Contacting the Manufacturer: For any requirement in this AD
to obtain instructions from a manufacturer, the instructions must be
accomplished using a method approved by the Manager, International
Section, Transport Standards Branch, FAA; or EASA; or Airbus SAS's
EASA Design Organization Approval (DOA). If approved by the DOA, the
approval must include the DOA-authorized signature.
    (3) Required for Compliance (RC): For any service information
referenced in EASA AD 2020-0030 that contains RC procedures and
tests: Except as required by paragraph (i)(2) of this AD, RC
procedures and tests must be done to comply with this AD; any
procedures or tests that are not identified as RC are recommended.
Those procedures and tests that are not identified as RC may be
deviated from using accepted methods in accordance with the
operator's maintenance or inspection program without obtaining
approval of an AMOC, provided the procedures and tests identified as
RC can be done and the airplane can be put back in an airworthy
condition. Any substitutions or changes to procedures or tests
identified as RC require approval of an AMOC.

(j) Related Information

    For more information about this AD, contact Sanjay Ralhan,
Aerospace Engineer, Large Aircraft Section, International Validation
Branch, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone
and fax<PHONE_NUMBER>; email<EMAIL_ADDRESS>
(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the service information listed
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do
the actions required by this AD, unless this AD specifies otherwise.
    (3) The following service information was approved for IBR on
October 9, 2020.
    (i) European Union Aviation Safety Agency (EASA) AD 2020-0030,
dated February 18, 2020.
    (ii) [Reserved]
    (4) For information about EASA AD 2020-0030, contact the EASA,
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221
8999 000; email<EMAIL_ADDRESS>internet www.easa.europa.eu. You
may find this EASA AD on the EASA website at https://ad.easa.europa.eu.
    (5) You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 2200 South 216th St.,
Des Moines, WA. For information on the availability of this material
at the FAA, call<PHONE_NUMBER>. This material may be found in the AD
docket on the internet at https://www.regulations.gov by searching
for and locating Docket No. FAA-2020-0327.
    (6) You may view this material that is incorporated by reference
at the National Archives and Records Administration (NARA). For
information on the availability of this material at NARA, email
<EMAIL_ADDRESS>or go to https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on August 21, 2020.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2020-19581 Filed 9-3-20; 8:45 am]
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