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Cyromazine; Pesticide Tolerances

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Information about this document as published in the Federal Register.

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Environmental Protection Agency (EPA).


Final rule.


This regulation establishes tolerances for residues of cyromazine in or on succulent beans at 2.0 parts per million (ppm). Interregional Research Project Number 4 (IR-4) requested these tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA).


This regulation is effective April 28, 2010. Objections and requests for hearings must be received on or before June 28, 2010, and must be filed in accordance with the instructions provided in 40 CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).


EPA has established a docket for this action under docket identification (ID) number EPA-HQ-OPP-2008-0866. All documents in the docket are listed in the docket index available at Although listed in the index, some information is not publicly available, e.g., Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available in the electronic docket at, or, if only available in hard copy, at the OPP Regulatory Public Docket in Rm. S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The Docket Facility is open from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The Docket Facility telephone number is (703) 305-5805.

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Barbara Madden, Registration Division, Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: (703) 305-6463; e-mail address:

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I. General Information

A. 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. Potentially affected entities may include, but are not limited to those engaged in the following activities:

  • Crop production (NAICS code 111).
  • Animal production (NAICS code 112).
  • Food manufacturing (NAICS code 311).
  • Pesticide manufacturing (NAICS code 32532).

This listing is not intended to be exhaustive, but rather to provide a guide for readers regarding entities likely to be affected by this action. Other types of entities not listed in this unit could also be affected. The North American Industrial Classification System (NAICS) codes have been provided to assist you and others in determining whether this action might apply to certain entities. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed under FOR FURTHER INFORMATION CONTACT.

B. How Can I Access Electronic Copies of this Document?

In addition to accessing electronically available documents at, you may access this Federal Register document electronically through the EPA Internet under the “Federal Register” listings at​fedrgstr. You may also access a frequently updated electronic version of EPA's tolerance regulations at 40 CFR part 180 through the Government Printing Office's e-CFR cite at​ecfr.

To access the OPPTS harmonized test guidelines referenced in this document electronically please go to​oppts and select “Test Methods & Guidelines” on the left-side navigation menu.Start Printed Page 22253

C. Can I File an Objection or Hearing Request?

Under section 408(g) of FFDCA, 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-2009-0866 in the subject line on the first page of your submission. All requests must be in writing, and must be mailed or delivered to the Hearing Clerk as required by 40 CFR part 178 on or before June 28, 2010.

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 that does not contain any CBI for inclusion in the public docket that is described in ADDRESSES. Information not marked confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA without prior notice. Submit this copy, identified by docket ID number EPA-HQ-OPP-2008-0866, by one of the following methods:

  • Federal eRulemaking Portal: Follow the on-line instructions for submitting comments.
  • Mail: Office of Pesticide Programs (OPP) Regulatory Public Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001.
  • Delivery: OPP Regulatory Public Docket (7502P), Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only accepted during the Docket Facility's normal hours of operation (8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays). Special arrangements should be made for deliveries of boxed information. The Docket Facility telephone number is (703) 305-5805.

II. Petition for Tolerance

In the Federal Register of April 13, 2009 (74 FR 16866) (FRL-8396-6), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP 8E7470) by Interregional Research Project Number 4 (IR-4), 500 College Road East, Suite 201 W, Princeton, NJ 08540. The petition requested that 40 CFR 180.414 be amended by establishing tolerances for residues of the insecticide cyromazine, (N-cyclopropyl-1,3,5-triazine-2,4,6-triamine) in or on bean, succulent at 2.0 parts per million (ppm). That notice referenced a summary of the petition prepared by Syngenta, the registrant, on behalf of IR-4 which is available to the public in the docket, There were no comments received in response to the notice of filing.

III. 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 section 408(b)(2)(D) of FFDCA, and the factors specified in section 408(b)(2)(D) of FFDCA, 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 the petitioned-for tolerances for residues of cyromazine on bean, succulent at 2.0 ppm. EPA's assessment of exposures and risks associated with establishing tolerances 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. Cyromazine is not an eye irritant or a dermal sensitizer but is a mild skin irritant. The liver and bone marrow (hematological system) are the primary targets for oral toxicity for cyromazine based on a chronic dog study. Decrease in body weight and food consumption are also common effects of cyromazine as observed in chronic dog, rat, mouse, and rabbit studies. No dermal or systemic toxicity was seen at the highest dose tested in two 21-day dermal toxicity studies in rabbits. No neurotoxicity studies with cyromazine are available. However, the cyromazine chemical class (triazine) does not generally target the central or peripheral nervous system and available data show no evidence of neurotoxic potential for cyromazine. There is no evidence that cyromazine is teratogenic or that offspring are more susceptible than adults based on developmental toxicity studies in rats and rabbits. In the 2-generation reproduction study in rats no reproductive effects were observed. Cyromazine was shown not to be carcinogenic in mice or rats following long-term dietary administration and is classified as “not likely to be carcinogenic to humans.” The available mutagenicity data suggest that cyromazine does not have genotoxic activity. Specific information on the studies received and the nature of the adverse effects caused by cyromazine 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 in docket ID number EPA-HQ-OPP-2009-0866, pages 25-27 of the document titled “Cyromazine Human Health Risk Assessment for Proposed New Use of Cyromazine on Succulent Beans.”

B. Toxicological Endpoints

For hazards that have a threshold below which there is no appreciable risk, a toxicological point of departure (POD) is identified as the basis for derivation of reference values for risk assessment. The POD may be defined as the highest dose at which no adverse effects are observed (the NOAEL) in the toxicology study identified as appropriate for use in risk assessment. However, if a NOAEL cannot be determined, the lowest dose at which adverse effects of concern are identified (the LOAEL) or a Benchmark Dose (BMD) approach is sometimes used for risk assessment. Uncertainty/safety factors (UFs) are used in conjunction with the POD to take into account uncertainties inherent in the extrapolation from laboratory animal data to humans and in the variations in sensitivity among members of the human population as well as other unknowns. Safety is assessed for acute and chronic dietary risks by comparing aggregate food and water exposure to the pesticide to the acute population adjusted dose (aPAD) and chronic population adjusted dose (cPAD). The Start Printed Page 22254aPAD and cPAD are calculated by dividing the POD by all applicable UFs. Aggregate short-, intermediate-, and chronic-term risks are evaluated by comparing food, water, and residential exposure to the POD to ensure that the margin of exposure (MOE) called for by the product of all applicable UFs is not exceeded. This latter value is referred to as the Level of Concern (LOC).

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 greater than that 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​pesticides/​factsheets/​riskassess.htm.

A summary of the toxicological endpoints for cyromazine used for human risk assessment can be found at in docket ID number EPA-HQ-OPP-2009-0866, page 15 of the document titled “Cyromazine. Human Health Risk Assessment for Proposed New Use of Cyromazine on Succulent Beans.”

C. Exposure Assessment

1. Dietary exposure from food and feed uses. In evaluating dietary exposure to cyromazine, EPA considered exposure under the petitioned-for tolerances as well as all existing cyromazine tolerances in 40 CFR 180.414. EPA assessed dietary exposures from cyromazine 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 cyromazine; therefore, a quantitative acute dietary exposure assessment is unnecessary.

ii. Chronic exposure. A chronic dietary risk assessments was conducted for cyromazine using the Dietary Exposure Evaluation Model (DEEM-FCID, Version 2.03), which uses food consumption data from the USDA's Continuing Surveys of Food Intakes by Individuals (CSFII) from 1994-1996 and 1998. As to residue levels in food, tolerance level residues and 100% crop treated assumptions were used. DEEM default and empirical processing factors were used to modify the tolerance values.

iii. Cancer. Based on the absence of evidence of carcinogenicity in two adequate rodent carcinogenicity studies, EPA has classified cyromazine as “not likely to be carcinogenic to humans.” Therefore, a quantitative exposure assessment to evaluate cancer risk is unnecessary.

iv. Anticipated residue and percent crop treated (PCT) information. EPA did not use anticipated residue and/or PCT information in the dietary assessment for cyromazine. Tolerance level residues and/or 100% crop treated 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 cyromazine in drinking water. These simulation models take into account data on the physical, chemical, and fate/transport characteristics of cyromazine. Further information regarding EPA drinking water models used in pesticide exposure assessment can be found at​oppefed1/​models/​water/​index.htm. Based on the First Index Reservoir Screening Tool (FIRST) and Screening Concentration in Ground Water (SCI-GROW) models, the estimated drinking water concentrations (EDWCs) of cyromazine for chronic exposures for non-cancer assessments are estimated to be 15.8 parts per billion (ppb) for surface water and 1.1 ppb for ground water. Modeled estimates of drinking water concentrations were directly entered into the dietary exposure model. For chronic dietary risk assessment, the water concentration of value 15.8 ppb was used to assess the contribution to drinking water.

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). Cyromazine is not registered for any specific use patterns that would result in residential exposure.

4. Cumulative effects from substances with a common mechanism of toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when considering whether to establish, modify, or revoke a tolerance, the Agency consider “available information” concerning the cumulative effects of a particular pesticide's residues and “other substances that have a common mechanism of toxicity.”

Cyromazine contains a symmetrical triazine substructure like the herbicides simazine and atrazine, but atrazine and simazine are chlorotriazines, and the toxicity of these chemicals is associated with the presence of a chlorine substituent on the triazine ring. Cyromazine is not a chlorotriazine. The chlorotriazines have a much different toxicological profile than does cyromazine which does not have a chlorine substituent on the triazine ring. EPA has not found cyromazine to share a common mechanism of toxicity with any other substances, and cyromazine does not appear to produce a toxic metabolite produced by other substances. For the purposes of this tolerance action, therefore, EPA has assumed that cyromazine does not have a common mechanism of toxicity with other substances. For information regarding EPA's efforts to determine which chemicals have a common mechanism of toxicity and to evaluate the cumulative effects of such chemicals, see EPA's website at​pesticides/​cumulative.

D. Safety Factor for Infants and Children

1. In general. Section 408(b)(2)(C) of FFDCA provides that EPA shall apply an additional tenfold (10X) margin of safety for infants and children in the case of threshold effects to account for prenatal and postnatal toxicity and the completeness of the database on toxicity and exposure unless EPA determines based on reliable data that a different margin of safety will be safe for infants and children. This additional margin of safety is commonly referred to as the FQPA SF. In applying this provision, EPA either retains the default value of 10X, or uses a different additional safety factor when reliable data available to EPA support the choice of a different factor.

2. Prenatal and postnatal sensitivity. Based on the available data, there is no quantitative and qualitative evidence of increased susceptibility observed following in utero cyromazine exposure to rats and rabbits or following prenatal/postnatal exposure in the 2-generation reproduction study. The database is considered adequate for selection of study endpoints and determination of a dose/response to characterize the potential prenatal or postnatal toxicity of cyromazine to infants and children. No increase in susceptibility was seen in developmental toxicity studies in rat and rabbit or reproductive toxicity studies in the rat. Toxicity to offspring was observed at dose levels the same or greater than those causing maternal or parental toxicity. Based on the results of developmental and reproductive toxicity studies, there is not a concern for increased qualitative and/or quantitative susceptibility following in utero exposure to cyromazine.

3. Conclusion. EPA has determined that reliable data show the safety of Start Printed Page 22255infants and children would be adequately protected if the FQPA SF were reduced to 1X. That decision is based on the following findings:

i. The toxicity database for cyromazine is complete except for acute and subchronic neurotoxicity studies and immunotoxicity testing. Recent changes to 40 CFR part 158 make these studies (OPPTS Guideline 870.7800) required for pesticide registration; however, the available data for cyromazine do not show potential for neurotoxicity or immunotoxicity. Although specific neurotoxicity studies have not yet been submitted, there is no evidence of neurotoxicity in any study in the toxicity database for cyromazine. In the absence of specific immunotoxicity studies, EPA has evaluated the available cyromazine toxicity database to determine whether an additional database uncertainty factor is needed to account for potential immunotoxicity. No evidence of immunotoxicity was found. Due to the lack of evidence of immunotoxicity for cyromazine, EPA does not believe that conducting immunotoxicity testing will result in a NOAEL less than the cRfD NOAEL of 1.5 mg/kg bw/day already established for cyromazine. Consequently, the EPA believes the existing data are sufficient for endpoint selection for exposure/risk assessment scenarios and for evaluation of the requirements under the FQPA, and an additional database uncertainty factor does not need to be applied.

ii. There is no indication that cyromazine is a neurotoxic chemical and there is no need for a developmental neurotoxicity study or additional UFs to account for neurotoxicity.

iii. There is no evidence that cyromazine results in increased susceptibility in in utero rats or rabbits in the prenatal developmental studies or in young rats in the 2-generation reproduction study.

iv. There are no residual uncertainties identified in the exposure databases. The dietary food exposure assessments were performed based on 100 PCT and tolerance-level residues. EPA made conservative (protective) assumptions in the ground and surface water modeling used to assess exposure to cyromazine in drinking water.

E. Aggregate Risks and Determination of Safety

EPA determines whether acute and chronic pesticide exposures are safe by comparing aggregate exposure estimates to the aPAD and cPAD. The aPAD and cPAD represent the highest safe exposures, taking into account all appropriate SFs. EPA calculates the aPAD and cPAD by dividing the POD by all applicable UFs. For linear cancer risks, EPA calculates the probability of additional cancer cases given the estimated aggregate exposure. Short-, intermediate-, and chronic-term risks are evaluated by comparing the estimated aggregate food, water, and residential exposure to the POD to ensure that the MOE called for by the product of all applicable UFs is not exceeded.

1. Acute risk. An acute aggregate risk assessment takes into account exposure estimates from acute dietary consumption of food and drinking water. No adverse effect resulting from a single-oral exposure was identified and no acute dietary endpoint was selected. Therefore, cyromazine is not expected to pose an acute risk.

2. Chronic risk. Using the exposure assumptions described in this unit for chronic exposure, EPA has concluded that chronic exposure to cyromazine from food and water will utilize 85% of the cPAD for children 1 to 2 years old, the population group receiving the greatest exposure. There are no residential uses for cyromazine.

3. Short- and intermediate term risk. Short- and intermediate-term aggregate exposure takes into account short-term and intermediate-term residential exposure plus chronic exposure to food and water (considered to be a background exposure level). Cyromazine is not registered for any use patterns that would result in residential exposure. Therefore, the short-term and intermediate-term aggregate risk is the sum of the risk from exposure to cyromazine through food and water and will not be greater than the chronic aggregate risk.

4. Aggregate cancer risk for U.S. population. Cyromazine is classified as a “Group E” chemical (negative for carcinogenicity in humans). This classification is based on the lack of evidence of carcinogenicity in mice and rats. EPA does not expect cyromazine to pose a cancer risk.

5. Determination of safety. Based on these risk assessments, EPA concludes that there is a reasonable certainty that no harm will result to the general population, or to infants and children from aggregate exposure to cyromazine residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

Methods AG-408 [high-performance liquid chromatography/ultraviolet (HPLC/UV)] and AG-417A [gas-liquid chromatography/nitrogen-phosphorus detector (GLC/NPD)] are the tolerance enforcement methods for cyromazine as published in the Pesticide Analytical Manual (PAM), Vol. II. These methods combined and with minor modifications comprise Method AG-621. The residue data submitted in support of this petition were generated using Methods AG-408 and AG-621. Method AG-621 has been adequately validated for use for the determination of residues of cyromazine in/on bulb vegetables, leafy Brassica vegetables, and turnip greens. Method AG-408 is adequate for enforcement of the proposed tolerance for residues of cyromazine.

B. International Residue Limits

There are currently no established Codex maximum residue limits (MRLs) for residues of cyromazine on succulent beans.

V. Conclusion

Therefore, tolerances are established for residues of cyromazine, N-cyclopropyl-1,3,5-triazine-2,4,6-triamine, in or on bean, succulent at 2.0 ppm.

VI. Statutory and Executive Order Reviews

This final rule establishes tolerances under section 408(d) of FFDCA in response to a petition submitted to the Agency. The Office of Management and Budget (OMB) has exempted these types of actions from review under Executive Order 12866, entitled Regulatory Planning and Review (58 FR 51735, October 4, 1993). Because this final rule has been exempted from review under Executive Order 12866, this final rule is not subject to Executive Order 13211, entitled Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355, May 22, 2001) or Executive Order 13045, entitled Protection of Children from Environmental Health Risks and Safety Risks (62 FR 19885, April 23, 1997). This final rule does not contain any information collections subject to OMB approval under the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et seq., nor does it require any special considerations under Executive Order 12898, entitled Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations (59 FR 7629, February 16, 1994).

Since tolerances and exemptions that are established on the basis of a petition under section 408(d) of FFDCA, such as the tolerance in this final rule, do not require the issuance of a proposed rule, the requirements of the Regulatory Start Printed Page 22256Flexibility Act (RFA) (5 U.S.C. 601 et seq.) do not apply.

This final rule directly regulates growers, food processors, food handlers, and food retailers, not States or tribes, nor does this action alter the relationships or distribution of power and responsibilities established by Congress in the preemption provisions of section 408(n)(4) of FFDCA. As such, the Agency has determined that this action will not have a substantial direct effect on States or tribal governments, on the relationship between the national government and the States or tribal governments, or on the distribution of power and responsibilities among the various levels of government or between the Federal Government and Indian tribes. Thus, the Agency has determined that Executive Order 13132, entitled Federalism (64 FR 43255, August 10, 1999) and Executive Order 13175, entitled Consultation and Coordination with Indian Tribal Governments (65 FR 67249, November 9, 2000) do not apply to this final rule. In addition, this final rule does not impose any enforceable duty or contain any unfunded mandate as described under Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law 104-4).

This action does not involve any technical standards that would require Agency consideration of voluntary consensus standards pursuant to section 12(d) of the National Technology Transfer and Advancement Act of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 note).

VII. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report to each House of the Congress and to the Comptroller General of the United States. EPA will submit a report containing this rule and other required information to the U.S. Senate, the U.S. House of Representatives, and the Comptroller General of the United States prior to publication of this final rule in the Federal Register. This final rule is not a “major rule” as defined by 5 U.S.C. 804(2).

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List of Subjects in 40 CFR Part 180

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Dated: March 26, 2010.

Lois Rossi,

Director, Registration DivisionOffice of Pesticide Programs.

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Therefore, 40 CFR chapter I is amended as follows:

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1. The authority citation for part 180 continues to read as follows:

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Authority: 21 U.S.C. 321(q), 346a and 371.

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2. Section 180.414 is amended by alphabetically adding the following commodity to the table in paragraph (a)(1) to read as follows:

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Cyromazine; tolerances for residues

(a)* * * (1)* * *

CommodityParts per million
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Bean, succulent2.0
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[FR Doc. 2010-9741 Filed 4-27-10; 8:45 am]