Dicamba; Pesticide Tolerances


Federal Register, Volume 81 Issue 236 (Thursday, December 8, 2016)

Federal Register Volume 81, Number 236 (Thursday, December 8, 2016)

Rules and Regulations

Pages 88627-88634

From the Federal Register Online via the Government Publishing Office www.gpo.gov

FR Doc No: 2016-29245




40 CFR Part 180

EPA-HQ-OPP-2010-0496, EPA-HQ-OPP-2012-0841; FRL-9954-37

Dicamba; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.


SUMMARY: This regulation establishes tolerances for residues of dicamba in or on cotton, gin byproducts; cotton, undelinted seed; soybean, forage; and soybean, hay. Monsanto Company requested these tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA).

DATES: This regulation is effective December 8, 2016. Objections and requests for hearings must be received on or before February 6, 2017, and must be filed in accordance with the instructions provided in 40 CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

Page 88628

ADDRESSES: The dockets for this action, identified by docket identification (ID) number EPA-HQ-OPP-2010-0496 for soybeans and EPA-

HQ-OPP-2012-0841 for cotton respectively are available at http://www.regulations.gov or at the Office of Pesticide Programs Regulatory Public Docket (OPP Docket) in the Environmental Protection Agency Docket Center (EPA/DC), West William Jefferson Clinton Bldg., Rm. 3334, 1301 Constitution Ave. NW., Washington, DC 20460-0001. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the OPP Docket is (703) 305-5805. Please review the visitor instructions and additional information about the docket available at http://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: Michael Goodis, Registration Division (7505P), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave. NW., Washington, DC 20460-0001; main telephone number: (703) 305-7090; email address: RDFRNotices@epa.gov.


  1. General Information

    1. Does this action apply to me?

      You may be potentially affected by this action if you are an agricultural producer, food manufacturer, or pesticide manufacturer. The following list of North American Industrial Classification System (NAICS) codes is not intended to be exhaustive, but rather provides a guide to help readers determine whether this document applies to them. Potentially affected entities may include:

      Crop production (NAICS code 111).

      Animal production (NAICS code 112).

      Food manufacturing (NAICS code 311).

      Pesticide manufacturing (NAICS code 32532).

    2. How can I get electronic access to other related information?

      You may access a frequently updated electronic version of EPA's tolerance regulations at 40 CFR part 180 through the Government Printing Office's e-CFR site at http://www.ecfr.gov/cgi-bin/text-idx?&c=ecfr&tpl=/ecfrbrowse/Title40/40tab_02.tpl.

    3. How can I file an objection or hearing request?

      Under FFDCA section 408(g), 21 U.S.C. 346a, any person may file an objection to any aspect of this regulation and may also request a hearing on those objections. You must file your objection or request a hearing on this regulation in accordance with the instructions provided in 40 CFR part 178. To ensure proper receipt by EPA, you must identify docket ID number EPA-HQ-OPP-2010-0496 and EPA-HQ-OPP-2012-0841 in the subject line on the first page of your submission. All objections and requests for a hearing must be in writing, and must be received by the Hearing Clerk on or before February 6, 2017. Addresses for mail and hand delivery of objections and hearing requests are provided in 40 CFR 178.25(b).

      In addition to filing an objection or hearing request with the Hearing Clerk as described in 40 CFR part 178, please submit a copy of the filing (excluding any Confidential Business Information (CBI)) for inclusion in the public docket. Information not marked confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA without prior notice. Submit the non-CBI copy of your objection or hearing request, identified by docket ID number EPA-HQ-OPP-2010-0496 and EPA-

      HQ-OPP-2012-0841, by one of the following methods:

      Federal e-Rulemaking Portal: http://www.regulations.gov. Follow the online instructions for submitting comments. Do not submit electronically any information you consider to be CBI or other information whose disclosure is restricted by statute.

      Mail: OPP Docket, Environmental Protection Agency Docket Center (EPA/DC), (28221T), 1200 Pennsylvania Ave. NW., Washington, DC 20460-0001.

      Hand Delivery: To make special arrangements for hand delivery or delivery of boxed information, please follow the instructions at http://www.epa.gov/dockets/contacts.html.

      Additional instructions on commenting or visiting the docket, along with more information about dockets generally, is available at http://www.epa.gov/dockets.

  2. Summary of Petitioned-For Tolerance

    In the Federal Register of August 4, 2010 (75 FR 46924) (FRL-8834-

    9) and December 19, 2012 (77 FR 75082) (FRL-9372-6), EPA issued a document pursuant to FFDCA section 408(d)(3), 21 U.S.C. 346a(d)(3), announcing the filing of pesticide petitions (PP 0F7725 and 2F8067, respectively) by Monsanto Company, 1300 I St. NW., Suite 450 East, Washington, DC 20052. The petitions requested that 40 CFR part 180 be amended by establishing tolerances for residues of the herbicide dicamba, 3,6-dichloro-o-anisic acid and its metabolites 3,6-dichloro-5-

    hydroxy-o-anisic acid (5-OH dicamba) and 3,6-dichloro-2-hydroxybenzoic acid (DCSA), as follows: PP 0F7725 requested tolerances for residues in or on soybean, forage at 45 parts per million (ppm) and soybean, hay at 70 ppm and PP 2F8067 requested tolerances for residues in or on cotton, undelinted seed at 3 ppm and cotton, gin byproducts at 70 ppm. Those documents referenced summaries of the petitions prepared by Monsanto Company, the registrant, which are available in the dockets, http://www.regulations.gov. Comments were received, and EPA's responses to these comments are discussed in Unit IV.C.

    Based upon review of the data supporting the petition, EPA is establishing tolerances for soybean, forage and soybean, hay that are higher than requested. The reason for these changes are explained in Unit IV.D.

  3. Aggregate Risk Assessment and Determination of Safety

    Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a tolerance (the legal limit for a pesticide chemical residue in or on a food) only if EPA determines that the tolerance is ``safe.'' Section 408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there is a reasonable certainty that no harm will result from aggregate exposure to the pesticide chemical residue, including all anticipated dietary exposures and all other exposures for which there is reliable information.'' This includes exposure through drinking water and in residential settings, but does not include occupational exposure. Section 408(b)(2)(C) of FFDCA requires EPA to give special consideration to exposure of infants and children to the pesticide chemical residue in establishing a tolerance and to ``ensure that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to the pesticide chemical residue. . . .''

    Consistent with FFDCA section 408(b)(2)(D), and the factors specified in FFDCA section 408(b)(2)(D), EPA has reviewed the available scientific data and other relevant information in support of this action. EPA has sufficient data to assess the hazards of and to make a determination on aggregate exposure for dicamba, including exposure resulting from the tolerances established by this action. EPA's assessment of exposures and risks associated with dicamba follows.

    1. Toxicological Profile

      EPA has evaluated the available toxicity data and considered its validity,

      Page 88629

      completeness, and reliability, as well as the relationship of the results of the studies to human risk. EPA has also considered available information concerning the variability of the sensitivities of major identifiable sub-groups of consumers, including infants and children.

      For dicamba, toxicology studies for dicamba acid; its salts (isopropylamine (IPA), diglycolamine (DGA), and N, N-Bis-(3-

      aminopropyl) methylamine (BAPMA)); and its plant metabolites (DCSA (3, 6-dichlorosalicylic acid) and DCGA (3, 6-dichlorogentisic acid)) were all considered for risk assessment. The dicamba BAPMA salt is the BAPMA base added to the dicamba acid form. The DCSA exposure is primarily from dietary exposures (food + water) from uses on transgenic crops, and the dicamba acid exposure is relevant for the incidental oral exposure. In scenarios where co-exposure to the various forms could occur, the most protective point of departure (POD) was utilized for regulation.

      Neurotoxic signs (e.g., ataxia, decreased motor activity, impaired righting reflex and gait) were observed in dicamba acid studies in rats and rabbits at doses over 150 mg/kg/day. The DCSA metabolite is less neurotoxic than dicamba acid, although a rat developmental study involving the BAPMA salt indicated neurotoxic effects (e.g., unsteady gait, ataxia, and convulsions) at lower doses (86 mg/kg/day).

      The rat reproduction study and the developmental studies in rats and rabbits showed no evidence (qualitative or quantitative) for increased susceptibility following in utero or postnatal exposure of dicamba acid or its salts. In the rabbit developmental toxicity study, a single incidence of abortion (1/20 does) was seen at doses that also caused maternal toxicity, as evidenced by clinical signs of neurotoxicity. In a 2-generation reproductive toxicity study involving dicamba acid, offspring toxicity was manifested as decreases in pup weight at a dose where parental toxicity was also observed. There was however, an indication of potential increased quantitative susceptibility from exposure to the metabolite DCSA (decreased pup body weight was observed at 37 mg/kg/day, where no parental toxic effects were noted).

      Dicamba is classified as ``not likely to be carcinogenic to humans''. Mutagenicity studies did not demonstrate mutagenic concern for dicamba. There was no evidence of dermal or systemic toxicity following repeated dermal application of dicamba acid or the salts at the limit dose (1,000 mg/kg/day). There is no concern for immunotoxicity following exposure to dicamba. Following oral administration, dicamba is rapidly absorbed and rapidly excreted in urine and feces without significant metabolism. Dicamba has a low acute toxicity via the oral, dermal or inhalation route (Acute Toxicity Categories III or IV). It is an eye and dermal irritant but it is not a skin sensitizer.

      Specific information on the studies received and the nature of the adverse effects caused by dicamba as well as the no-observed-adverse-

      effect-level (NOAEL) and the lowest-observed-adverse-effect-level (LOAEL) from the toxicity studies can be found at http://www.regulations.gov in document Dicamba and Dicamba BAPMA salt: Human-

      Health risk Assessment for Proposed Section 3 New Uses on dicamba-

      tolerant Cotton and Soybean in docket ID number EPA-HQ-OPP-2016-0187.

    2. Toxicological Points of Departure/Levels of Concern

      Once a pesticide's toxicological profile is determined, EPA identifies toxicological points of departure (POD) and levels of concern to use in evaluating the risk posed by human exposure to the pesticide. For hazards that have a threshold below which there is no appreciable risk, the toxicological POD is used as the basis for derivation of reference values for risk assessment. PODs are developed based on a careful analysis of the doses in each toxicological study to determine the dose at which no adverse effects are observed (the NOAEL) and the lowest dose at which adverse effects of concern are identified (the LOAEL). Uncertainty/safety factors are used in conjunction with the POD to calculate a safe exposure level--generally referred to as a population-adjusted dose (PAD) or a reference dose (RfD)--and a safe margin of exposure (MOE). For non-threshold risks, the Agency assumes that any amount of exposure will lead to some degree of risk. Thus, the Agency estimates risk in terms of the probability of an occurrence of the adverse effect expected in a lifetime. For more information on the general principles EPA uses in risk characterization and a complete description of the risk assessment process, see http://www.epa.gov/pesticides/factsheets/riskassess.htm.

      A summary of the toxicological endpoints for dicamba used for human risk assessment is shown in Table 1 of this unit.

      Table 1--Summary of Toxicological Doses and Endpoints for Dicamba Acid and Dicamba BAPMA Salt for Use in Human

      Health Risk Assessment


      Point of departure

      Exposure/scenario and uncertainty/ RfD, PAD, LOC for Study and toxicological effects

      safety factors risk assessment


      Acute dietary (Females 13 to 50 Not Applicable (NA). NA................. No developmental toxicity

      years of age). attributed to acute exposure in

      the toxicity database.


      Acute dietary (General population NOAEL = 29 mg/kg/day Acute RfD = 0.29 mg/ Developmental Rat Study Dicamba

      including infants and children). UFA = 10x........... kg/day. BAPMA.

      UFH = 10x........... aPAD = 0.29 mg/kg/ LOAEL = 86 mg/kg/day in dams based

      FQPA SF = 1x........ day. on ataxia, unsteady gait and

      convulsions observed shortly

      after dosing.


      Chronic dietary (All populations) Offspring NOAEL= 4 Chronic RfD = 0.04 Reproductive Rat Study with

      mg/kg/day. mg/kg/day. Metabolite DCSA.

      UFA = 10x........... cPAD = 0.04 mg/kg/ Offspring LOAEL = 37 mg/kg/day

      UFH = 10x........... day. based on decreased pup weights in

      FQPA SF = 1x........ F1 generation PND 14 and 21 (both

      sexes) and week 18 (females).


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      Incidental oral short- (1 to 30 Offspring NOAEL= 136 Residential LOC for Reproductive Study in Rats with

      days) and intermediate- (1 to 6 mg/kg/day. MOE = 100. Dicamba Acid Offspring.

      months) term. UFA = 10x........... LOAEL = 450 mg/kg/day based on

      UFH = 10x........... decreased pup weights.

      FQPA SF = 1x........


      No endpoints for assessing dermal risk were identified since the dermal toxicology studies for dicamba acid, IPA

      and DGA salts all had NOAELs of 1,000 mg/kg/day..


      Inhalation short-, intermediate-, Inhalation study Residential LOC for Aerosol Inhalation Rat Study with

      and long-term. NOAEL = 0.005 mg/L. MOE = 30. Dicamba Acid.

      UFA = 3x............ LOAEL = 0.050 mg/L based on

      UFH = 10x........... minimal multifocal bronchiole-

      FQPA SF = 1x........ alveolar hyperplasia in males,

      multiple microscopic findings in

      the lung and associated lymph

      nodes in females.


      Cancer (Oral, dermal, inhalation) Dicamba is classified as ``not likely to be carcinogenic to humans''


      FQPA SF = Food Quality Protection Act Safety Factor. LOAEL = lowest-observed-adverse-effect-level. LOC = level

      of concern. mg/kg/day = milligram/kilogram/day. MOE = margin of exposure. NOAEL = no-observed-adverse-effect-

      level. PAD = population adjusted dose (a = acute, c = chronic). RfD = reference dose. UF = uncertainty factor.

      UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity among

      members of the human population (intraspecies). UFL = use of a LOAEL to extrapolate a NOAEL. PND = postnatal


    3. Exposure Assessment

      1. Dietary exposure from food and feed uses. In evaluating dietary exposure to dicamba, EPA considered exposure under the petitioned-for tolerances as well as all existing dicamba tolerances in 40 CFR 180.227. EPA assessed dietary exposures from dicamba in food as follows:

        i. Acute exposure. Quantitative acute dietary exposure and risk assessments are performed for a food-use pesticide, if a toxicological study has indicated the possibility of an effect of concern occurring as a result of a 1-day or single exposure.

        Such effects were identified for dicamba. In estimating acute dietary exposure, EPA used food consumption information from the United States Department of Agriculture (USDA) 2003-2008 National Health and Nutrition Examination Survey, What We Eat in America (NHANES/WWEIA). As to residue levels in food, EPA used tolerance levels and 100 percent crop treated (PCT) for the acute dietary exposure assessment.

        ii. Chronic exposure. In conducting the chronic dietary exposure assessment EPA used the food consumption data from the USDA 2003-2008 National Health and Nutrition Examination Survey, What We Eat in America (NHANES/WWEIA). As to residue levels in food, EPA used average residues based on field trial studies for crops, tolerance levels for livestock commodities and relevant PCT data for several existing uses to assess chronic dietary exposure.

        iii. Cancer. Based on the data summarized in Unit III.A., EPA has concluded that dicamba does not pose a cancer risk to humans. Therefore, a dietary exposure assessment for the purpose of assessing cancer risk is unnecessary.

        iv. Anticipated residue and percent crop treated (PCT) information. Section 408(b)(2)(E) of FFDCA authorizes EPA to use available data and information on the anticipated residue levels of pesticide residues in food and the actual levels of pesticide residues that have been measured in food. If EPA relies on such information, EPA must require pursuant to FFDCA section 408(f)(1) that data be provided 5 years after the tolerance is established, modified, or left in effect, demonstrating that the levels in food are not above the levels anticipated. For the present action, EPA will issue such data call-ins as are required by FFDCA section 408(b)(2)(E) and authorized under FFDCA section 408(f)(1). Data will be required to be submitted no later than 5 years from the date of issuance of these tolerances.

        Section 408(b)(2)(F) of FFDCA states that the Agency may use data on the actual percent of food treated for assessing chronic dietary risk only if:

        Condition a: The data used are reliable and provide a valid basis to show what percentage of the food derived from such crop is likely to contain the pesticide residue.

        Condition b: The exposure estimate does not underestimate exposure for any significant subpopulation group.

        Condition c: Data are available on pesticide use and food consumption in a particular area, the exposure estimate does not understate exposure for the population in such area.

        In addition, the Agency must provide for periodic evaluation of any estimates used. To provide for the periodic evaluation of the estimate of PCT as required by FFDCA section 408(b)(2)(F), EPA may require registrants to submit data on PCT.

        The Agency estimated the average PCT for existing uses as follows: Asparagus: 5%; barley: 5%; corn: 10%; oats: 2.5%; sorghum: 15%; sugarcane: 20%; sweet corn: 1%; and wheat: 10%.

        In most cases, EPA uses available data from United States Department of Agriculture/National Agricultural Statistics Service (USDA/NASS), proprietary market surveys, and the National Pesticide Use Database for the chemical/crop combination for the most recent 6 to 7 years. EPA uses an average PCT for chronic dietary risk analysis. The average PCT figure for each existing use is derived by combining available public and private market survey data for that use, averaging across all observations, and rounding to the nearest 5%, except for those situations in which the average PCT is less than one. In those cases, 1% is used as the average PCT and 2.5% is used as the maximum PCT. EPA uses a maximum PCT for acute dietary risk analysis. The

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        maximum PCT figure is the highest observed maximum value reported within the recent 6 years of available public and private market survey data for the existing use and rounded up to the nearest multiple of 5%.

        The Agency believes that the three conditions discussed in Unit III.C.1.iv. have been met. With respect to Condition a, PCT estimates are derived from Federal and private market survey data, which are reliable and have a valid basis. The Agency is reasonably certain that the percentage of the food treated is not likely to be an underestimation. As to Conditions b and c, regional consumption information and consumption information for significant subpopulations is taken into account through EPA's computer-based model for evaluating the exposure of significant sub-populations including several regional groups. Use of this consumption information in EPA's risk assessment process ensures that EPA's exposure estimate does not understate exposure for any significant subpopulation group and allows the Agency to be reasonably certain that no regional population is exposed to residue levels higher than those estimated by the Agency. Other than the data available through national food consumption surveys, EPA does not have available reliable information on the regional consumption of food to which dicamba may be applied in a particular area.

      2. Dietary exposure from drinking water. The Agency used screening level water exposure models in the dietary exposure analysis and risk assessment for dicamba in drinking water. These simulation models take into account data on the physical, chemical, and fate/transport characteristics of dicamba. Further information regarding EPA drinking water models used in pesticide exposure assessment can be found at http://www.epa.gov/oppefed1/models/water/index.htm.

        Based on the Pesticide Root Zone Model/Exposure Analysis Modeling System (PRZM/EXAMS) and Pesticide Root Zone Model Ground Water (PRZM GW), the estimated drinking water concentrations (EDWCs) of dicamba for acute exposures are calculated to be 53.37 parts per billion (ppb) for surface water and 329 ppb parent plus 0.041 ppb DCSA for ground water. For chronic exposures for non-cancer assessments are estimated to be 44.5 ppb for surface water and 187 ppb parent plus 0.041 ppb DCSA for ground water.

        Modeled estimates of drinking water concentrations were directly entered into the dietary exposure model. The combined estimated drinking water residues (parent + DCSA) for peak concentration used in the acute assessment and chronic were 329 and 187 ug/L (ppb), respectively.

      3. From non-dietary exposure. The term ``residential exposure'' is used in this document to refer to non-occupational, non-dietary exposure (e.g., for lawn and garden pest control, indoor pest control, termiticides, and flea and tick control on pets).

        There are no residential uses being proposed in connection with this action for either dicamba or the dicamba BAPMA salt; however, there are existing residential turf uses of dicamba that have been reassessed to reflect updates to the Agency's 2012 Residential Standard Operating Procedures (SOPs).

        There is no potential hazard via the dermal route for dicamba; therefore, the handler assessment includes only the inhalation route of exposure, and the post-application assessment includes only the incidental oral routes of exposure.

        The quantitative exposure/risk assessment developed for residential handlers to adults is based on the following lawn/turf application scenarios:

        Mix/Load/Apply Liquid with Hand-held Equipment

        Apply Ready-To-Use with Hand-held Equipment

        Load/Apply Granule with Hand-held Equipment

        The quantitative exposure/risk assessment for residential post-

        application exposures to children is based on the following scenarios:

        Children (1 to Children (1 to