Quiero saber acerca de...

9870

Federal Register / Vol. 86, No. 30 / Wednesday, February 17, 2021 / Rules and Regulations
jbell on DSKJLSW7X2PROD with RULES

occupational exposure. Section 408b2C of the 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 408b2D, and the factors specified therein, 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 orthosulfamuron including exposure resulting from the tolerances established by this action. EPAs assessment of exposures and risks associated with orthosulfamuron follows.
A. Toxicological Profile EPA has evaluated the available toxicity data and considered its validity, 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 subgroups of consumers, including infants and children.
Orthosulfamuron is included in a group of herbicides referred to as sulfonylureas that control weeds through inhibition of the enzyme acetolactate synthase ALS. The toxicological database for orthosulfamuron is complete and no additional data are required.
Orthosulfamuron showed low acute toxicity by all routes and no dermal irritation or sensitization Category IV
and was a mild eye irritant Category III. The major target organs of orthosulfamuron are the liver, kidneys and thyroid gland, with effects generally observed at high doses following chronic oral exposure. No evidence of preand/or post-natal quantitative or qualitative susceptibility was observed, and the database overall did not show evidence of neurotoxicity.
Thyroid follicular cell tumors were observed at high doses in only one sex and one species, and there was no evidence of genotoxicity. Therefore, in accordance with the EPA Final Guidelines for Carcinogen Risk Assessment March 2005, orthosulfamuron is classified as Suggestive Evidence of Carcinogenicity.
Specific information on the studies received and the nature of the adverse effects caused by orthosulfamuron as
VerDate Sep<11>2014

15:56 Feb 16, 2021

Jkt 253001

well as the no-observed-adverse-effectlevel NOAEL and the lowest-observedadverse-effect-level LOAEL from the toxicity studies can be found at http
www.regulations.gov in document Orthosulfamuron. Human Health Risk Assessment for Proposed New Uses on Small Fruit Vine Climbing Subgroup, Except Fuzzy Kiwifruit 1307F, Tree Nuts 1412, Non-Bearing Citrus Fruit 1010, and Non-Bearing Stone Fruit 1212 hereinafter Orthosulfamuron Human Health Risk Assessment on page numbers 2535 in docket ID
number EPAHQOPP20190580.
B. Toxicological Points of Departure/
Levels of Concern Once a pesticides 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 levelgenerally referred to as a population-adjusted dose PAD or a reference dose RfDand 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
www2.epa.gov/pesticide-science-andassessing-pesticide-risks/assessinghuman-health-risk-pesticides.
A summary of the toxicological endpoints for orthosulfamuron used for human risk assessment can be found on page 13 in the Orthosulfamuron Human Health Risk Assessment.
C. Exposure Assessment 1. Dietary exposure from food and feed uses. In evaluating dietary exposure to orthosulfamuron, EPA
considered exposure under the petitioned-for tolerances as well as all existing orthosulfamuron tolerances in 40 CFR 180.625. EPA assessed dietary
PO 00000

Frm 00034

Fmt 4700

Sfmt 4700

exposures from orthosulfamuron 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.
No such effects were identified in the toxicological studies for orthosulfamuron; therefore, a quantitative acute dietary exposure assessment is unnecessary.
ii. Chronic exposure. In conducting the chronic dietary exposure assessment, EPA used 20032008 food consumption data from the U.S.
Department of Agricultures USDAs National Health and Nutrition Examination Survey, What We Eat in America NHANES/WWEIA. As to residue levels in food, EPA assumed tolerance-level residues and 100 percent crop treated PCT.
iii. Cancer. EPA determines whether quantitative cancer exposure and risk assessments are appropriate for a fooduse pesticide based on the weight of the evidence from cancer studies and other relevant data. Cancer risk is quantified using a linear or nonlinear approach.
Based on the available data for orthosulfamuron, which is summarized in Unit III.A., EPA has concluded that a nonlinear approach is appropriate for assessing cancer risk to orthosulfamuron. The chronic dietary reference dose cRfD is significantly lower than the dose that caused thyroid tumors in male rats, and therefore is protective of potential carcinogenicity.
Cancer risk was assessed using the same exposure estimates as discussed in Unit III.C.1.ii., chronic exposure.
iv. Anticipated residue and percent crop treated PCT information. EPA did not use anticipated residue or PCT
information in the dietary assessment for orthosulfamuron. Tolerance-level residues and 100 PCT were assumed for all food commodities.
2. Dietary exposure from drinking water. The Agency used screening level water exposure models in the dietary exposure analysis and risk assessment for orthosulfamuron in drinking water.
These simulation models take into account data on the physical, chemical, and fate/transport characteristics of orthosulfamuron. Further information regarding EPA drinking water models used in pesticide exposure assessment can be found at http www2.epa.gov/
pesticide-science-and-assessingpesticide-risks/about-water-exposuremodels-used-pesticide.
Screening groundwater-sourced drinking water exposure estimates were
E:FRFM17FER1.SGM

17FER1