Document ID: EPA-HQ-OPP-2018-0243-0002
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2018-10-19T04:00Z

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Monsanto Company authorizes the EPA to publish the following summary of the petition to comply with the Food Quality Protection Act of 1996. An electronic copy is provided with this submission. 

ACTION: Notice of filing of pesticide petition and request for comment

Agency: Environmental Protection Agency (EPA)

Identifier: [EPA-HQ-OPP-2018-0243; FRL-xxxx-xx]

Administrative Code Citation:  40 CFR Part 180

Synopsis
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SUMMARY: This document announces the Agency's receipt of an initial filing of a pesticide petition requesting the modification of regulations for residues of a certain pesticide chemical in or on various food commodities.

SUPPLEMENTARY INFORMATION:

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Amended Tolerances

1. PP IN-11139. (EPA-HQ-OPP-2018-0243) Monsanto Company, 700 Chesterfield Parkway West, St. Louis, Missouri, proposes, 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 180.471 (a) General., by establishing tolerances for residues of the safener (inert ingredient), furilazole, 3-dichloroacetyl-5-(2-furanyl)-2,2-dimethyloxazolidine, in or on the raw agricultural commodities, corn, sweet, forage at 0.01 ppm, corn, sweet, kernel plus cob with husks removed at 0.01 ppm, and, corn, sweet, stover at 0.01 ppm.  Monsanto Company has submitted a rationale for the use of existing metabolism and residue data in field corn and sorghum as sufficient to support establishing tolerances for furilazole in raw agricultural commodities for sweet corn.  Contact:  RD.

A.	Residue Chemistry

	1.  Plant Metabolism. The metabolism in corn has been studied with radiolabeled furalizole in the green house and in the field.  Parent furilazole was not found in any of the corn samples. The metabolism of furilazole was also studied in a parallel experiment with sorghum in the field study with corn.  Parent furilazole was not found in any of the sorghum samples.  Furilazole is rapidly and extensively metabolized to a large number of highly polar metabolites characterized as weak organic acids or residues conjugated to natural sugars.  Similar metabolism with no parent furilazole is expected in sweet corn commodities.
      
      2.  Analytical method. An adequate analytical enforcement method for residues of furilazole in crops has been approved.  The method involves gas liquid chromatography coupled with either electron capture detection for corn or mass spectrometry with selected ion monitoring for sorghum.  The only difference between the methods is the technique used for detection.  Both approaches have a verified limit of quantitation of 0.01 ppm for parent furilazole in corn grain, forage, and stover, and sorghum grain, forage, stover, flour, and bran. The method involving electron capture detection is analogous to that validated by the Agency.  The analytical methodology developed for corn and sorghum is expected to apply to sweet corn.
      
      3.  Magnitude of the residues. Monsanto has conducted a field residue study at twenty sites with furilazole applied preemergence to corn at rates up to 0.75 pound per acre.  Analysis of corn forage, silage, fodder, and grain showed no residues of furilazole parent with an analytical method that is validated at the lower limit of 0.01 ppm.  Field residue studies at two sites with furilazole applied preemergence to corn at exaggerated rates up to 117 times the proposed maximum use rate showed no measurable residues (< 0.01 ppm) of furilazole parent in corn grain.  A field residue study has been conducted at thirteen sites with furilazole applied preemergence to sorghum according to labeled use rates.  Analysis of sorghum forage, stover, grain, flour and bran showed no residues of furilazole parent with an analytical method that was validated at the lower limit of 0.01 ppm.  No measurable residues (<0.01 ppm) of furilazole parent are expected in sweet corn from labeled use rates.

B.	Toxicological Profile
	A summary of the toxicology data supporting this petition was published in the Federal Register on April 3, 2002 (67 FR 15727) (FRL-6828-4).

C.	Aggregate Exposure

1.  Dietary exposure.  Potential dietary (food and water) exposures resulting from the use of furilazole were estimated using the Dietary Exposure Evaluation Model-Food Consumption Intake Database based on NHANES 2-day food consumption data for 2005-2010 and food translations based on EPA/USDA FCID recipe set as of August 2014 (DEEM-FCID, ver. 4.02, 05-10-c).  To assess potential exposures from food, Monsanto made the very conservative assumption that the entire corn and sorghum crops were treated with furilazole (i.e., 100% crop treated), that field corn, pop corn, sorghum and sweet corn (kernels plus cob with husk removed) commodities contain residues of furilazole at the existing or proposed tolerance level of their associated raw agricultural commodities, and that no losses occurred during storage, processing or cooking. The default processing factor of 1.5 was used for corn syrup.  For drinking water, Monsanto used the conservative estimates of furilazole concentration in surface water previously calculated by EPA and published in the Federal Register on April 3, 2002 (67 FR 15727) (FRL-6828-4). For surface water, the EPA used the Pesticide Root Zone/Exposure Analysis Modeling System (PRZM/EXAMS) model to calculate Estimated Environmental Concentrations (EECs) of 1.2 parts per billion (ppb), 0.8 ppb and 0.22 ppb for acute, chronic (non-cancer) and cancer risk assessments, respectively. Ground water residues of 0.02 ppb for all exposure scenarios were modeled using Screening Concentrations in Ground Water (SCI-GROW).

2. Non-dietary exposure. There are no residential or non-agricultural uses of furilazole. Therefore, non-dietary, non-occupational exposures to furilazole are expected to be negligible and were not included within this risk assessment.

D. Cumulative Effects
Monsanto has no reliable data or information to suggest that furilazole shares a common mechanism of toxicity with any other chemical. Therefore, only the potential effects of furilazole
are addressed in this document. 

E. Safety Determination

1. U.S. population. The toxicology endpoints used to assess potential acute, chronic and carcinogenic risks from furilazole were those previously identified by the EPA and published in
the Federal Register on April 3, 2002 (67 FR 15727), except as noted below. Acute dietary risks were assessed using an acute Population Adjusted Dose (aPAD) of 0.1 milligrams/kilogram/day (mg/kg/day). This was based on a No Observed Adverse Effect Level (NOAEL) of 10 mg/kg/day for increased resorptions in a developmental toxicity study in rats and a 100-fold uncertainty factor (UF). The only population subgroup of potential concern for this effect was females aged 13 and older because this is an in-utero effect applicable only to females of childbearing age. Acute risk assessments for other population subgroups were not conducted since no other acute toxicology endpoint was identified. 

Potential risks from chronic dietary exposure for all population subgroups were assessed using a chronic Population Adjusted Dose (cPAD) of 0.0026 mg/kg/day.  This was based on a NOAEL of 0.26 mg/kg/day for increased liver and kidney weights in a chronic rat study and an UF of 100. The EPA previously utilized a cPAD of 0.0009 mg/kg/day based on the same NOAEL but with an UF of 300 rather than 100 to account for the lack of a one-year dog study. However, since a one-year dog study is no longer typically required, Monsanto believes the additional 3X UF is no longer appropriate. Since furilazole is classified by the EPA as ``likely to be carcinogenic to humans'', potential carcinogenic risks have been quantified using the cancer slope factor (Q*) of 0.0274 (mg/kg/day)[ - 1] previously used by EPA.

The toxicology and exposure information available for furilazole was considered to be valid, reliable and complete according to current regulatory standards. No evidence of increased susceptibility of offspring was noted in rats or rabbits following in utero and/or postnatal exposure to furilazole. Therefore, the Agency has determined that no additional Food Quality Protection Act (FQPA) safety factor was needed to protect infants or children.

2. Acute risk. Based on the above assumptions, the 95th percentile for acute dietary exposure to furilazole for females age 13 to 50 was estimated to be 0.000084 mg/kg/day. This exposure represents 0.08% of the aPAD. In general, exposures utilizing less than 100% of the aPAD are not of concern. Therefore, Monsanto concludes that there is a reasonable certainty that acute dietary exposure to furilazole will not pose a significant risk to human health.

3. Chronic (non-cancer) risk. Based on the above assumptions, chronic dietary exposure to furilazole for the overall U.S. population was estimated to be 0.000035 mg/kg/day. This represents about 1.3% of the cPAD. Chronic dietary exposure for non-nursing infants, the most highly exposed population subgroup, was estimated to be 0.000145 mg/kg/day, which represents 5.6% of the cPAD. Both of these values are well below 100% of the cPAD. Therefore, Monsanto concludes that there is a reasonable certainty that chronic dietary exposure to furilazole will not pose a significant risk to human health.

4. Cancer risk. Based on the above assumptions, the average daily lifetime exposure to furilazole from food for the overall U.S. population was estimated to be 0.000023 mg/kg/day. Using linear low-dose extrapolation, the 95% upper confidence limit of the lifetime cancer risk associated with this level of exposure was estimated to be 6.4 x 10[ - 7]. Cancer risks less than approximately 1 x 10[ - 6] are generally considered to be negligible. Therefore, Monsanto concludes that there is a reasonable certainty that lifetime aggregate exposure to furilazole will not pose a significant risk of cancer.

5. Overall conclusion of safety. Based on the data summarized herein, Monsanto concludes that there is a reasonable certainty that no harm will result to the U.S. population, including
infants and children, from the current and proposed uses of furilazole.

F. International Tolerances
The Codex Alimentarius Commission has not established any maximum residue levels for furilazole.