Diflubenzuron; Pesticide Tolerances for Emergency Exemptions

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 categories and entities may include, but are not limited to:

------------------------------------------------------------------------ Examples of Categories NAICS Potentially Affected Entities ------------------------------------------------------------------------ Industry 111 Crop production 112 Animal production 311 Food manufacturing 32532 Pesticide manufacturing ------------------------------------------------------------------------

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

B. How Can I Get Additional Information, Including Copies of This Document and Other Related Documents?

1. Electronically.You may obtain electronic copies of this document, and certain other related documents that might be available electronically, from the EPA Internet Home Page at www.epa.gov/. To access this document, on the Home Page select ``Laws and Regulations'' and then look up the entry for this document under the ``Federal Register--Environmental Documents.'' You can also go directly to the Federal Register listings at www.epa.gov/fedrgstr/. 2. In person. The Agency has established an official record for this action under docket control number OPP-300921. The official record consists of the documents specifically referenced in this action, and other information related to this action, including any information claimed as Confidential Business Information (CBI). This official record includes the documents that are physically located in the docket, as well as the documents that are referenced in those documents. The public version of the official record does not include any information claimed as CBI. The public version of the official record, which includes printed, paper versions of any electronic comments submitted during an applicable comment period is available for inspection in the Public Information and Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall 2, 1921 Jefferson Davis Hwy., Arlington, VA, from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The PIRIB telephone number is (703) 305-5805.

II. Background and Statutory Findings

EPA, on its own initiative, in accordance with sections 408 (l)(6) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a, is establishing a tolerance for residues of the insecticide diflubenzuron and its metabolites PCA and CPU, expressed as parent compound, in or on pears at 0.5 part per million (ppm). This tolerance will expire and is revoked on March 31, 2001. EPA will publish a document in the Federal Register to remove the revoked tolerance from the Code of Federal Regulations. Section 408(l)(6) of the FFDCA requires EPA to establish a time- limited tolerance or exemption from the requirement for a tolerance for pesticide chemical residues in food that will result from the use of a pesticide under an emergency exemption granted by EPA under section 18 of FIFRA. Such tolerances can be established without providing notice or period for public comment. EPA does not intend for its actions on section 18 related tolerances to set binding precedents for the application of section 408 and the new safety standard to other tolerances and exemptions. Section 408(b)(2)(A)(i) of the 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) 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) 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. . . .'' Section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) authorizes EPA to exempt any Federal or State agency from any provision of FIFRA, if EPA determines that ``emergency conditions exist which require such exemption.'' This provision was not amended by Food Quality Protection Act (FQPA). EPA has established regulations governing such emergency exemptions in 40 CFR part 166.

III. Emergency Exemption for Diflubenzuron on Pears and FFDCA Tolerances

The Oregon and Washington Departments of Agriculture requested use of diflubenzuron on pears, for control of pear psylla, which had developed resistance to currently available pesticides, and was expected to cause significant economic loss if not adequately controlled. EPA has authorized under FIFRA section 18 the use of diflubenzuron on pears for

control of pear psylla in Oregon and Washington. After having reviewed the submission, EPA concurs that emergency conditions exist for these states. As part of its assessment of this emergency exemption, EPA assessed the potential risks presented by residues of diflubenzuron in or on pears. In doing so, EPA considered the safety standard in FFDCA section 408(b)(2), and EPA decided that the necessary tolerance under FFDCA section 408(l)(6) would be consistent with the safety standard and with FIFRA section 18. Consistent with the need to move quickly on the emergency exemption in order to address an urgent non-routine situation and to ensure that the resulting food is safe and lawful, EPA is issuing this tolerance without notice and opportunity for public comment as provided in section 408(l)(6). Although this tolerance will expire and is revoked on March 31, 2001, under FFDCA section 408(l)(5), residues of the pesticide not in excess of the amounts specified in the tolerance remaining in or on pears after that date will not be unlawful, provided the pesticide is applied in a manner that was lawful under FIFRA, and the residues do not exceed a level that was authorized by this tolerance at the time of that application. EPA will take action to revoke this tolerance earlier if any experience with, scientific data on, or other relevant information on this pesticide indicate that the residues are not safe. Because this tolerance is being approved under emergency conditions EPA has not made any decisions about whether diflubenzuron meets EPA's registration requirements for use on pears or whether a permanent tolerance for this use would be appropriate. Under these circumstances, EPA does not believe that this tolerance serves as a basis for registration of diflubenzuron by a State for special local needs under FIFRA section 24(c). Nor does this tolerance serve as the basis for any State other than Oregon and Washington to use this pesticide on this crop under section 18 of FIFRA without following all provisions of EPA's regulations implementing section 18 as identified in 40 CFR part 166. For additional information regarding the emergency exemption for diflubenzuron, contact the Agency's Registration Division at the address provided under the ``ADDRESSES'' section.

IV. Aggregate Risk Assessment and Determination of Safety

EPA performs a number of analyses to determine the risks from aggregate exposure to pesticide residues. For further discussion of the regulatory requirements of section 408 and a complete description of the risk assessment process, see the final rule on Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997) (FRL-5754-7) . Consistent with 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 diflubenzuron and to make a determination on aggregate exposure, consistent with section 408(b)(2), for a time-limited tolerance for residues of diflubenzuron and its metabolites PCA and CPU, expressed as parent compound on pears at 0.5 ppm. EPA's assessment of the dietary exposures and risks associated with establishing the tolerance 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. The nature of the toxic effects caused by diflubenzuron are discussed in this unit.

B. Toxicological Endpoint

1. Acute toxicity. A risk assessment for acute (1-day) dietary exposure is not necessary. One day single dose oral studies in rats and mice indicated only marginal effects on methemoglobin levels at a dose level of 10,000 milligrams/kilogram/day (mg/kg/day). 2. Short- and intermediate-term toxicity. The toxicological endpoint for short-term occupational or residential exposure (1-7 days) is sulfhemoglobinemia observed in the 14-day subchronic oral study in mice dosed with technical grade diflubenzuron. The no observed adverse effect level (NOAEL) in this study was 40 mg/kg/day, and the lowest observed adverse effect level (LOAEL) was 200 mg/kg/day. The toxicological endpoint for intermediate-term occupational or residential exposure (1 week to several months) is methemoglobinemia observed in the 13-week subchronic feeding study in dogs. For the purpose of risk assessments, the NOAEL of 1.64 mg/kg/day in this study should be rounded up to 2 mg/kg/day, so as to be consistent with the NOAEL of 2 mg/kg/day in the chronic study used to calculate the Reference Dose (RfD). The LOAEL in this study was 6.24 mg/kg/day. Since an oral NOAEL was selected for a dermal endpoint, a dermal absorption factor of 0.5% should be used for this risk assessment when converting dermal exposure to oral equivalents. Therefore, the dermal equivalent dose producing a NOAEL by the oral route is calculated to be 400 mg/kg/ day (2.0 mg/kg/day divided by 0.005 = 400 mg/kg/day). 3. Chronic toxicity. EPA has established the RfD for diflubenzuron at 0.02 mg/kg/day, based on the NOAEL of 2.0 mg/kg/day from the 52- week chronic oral study in dogs. Increases in methemoglobin and sulfhemoglobin were observed at the next higher dose level (LOAEL) of 10.0 mg/kg/day. An uncertainty factor of 100 was applied to account for the interspecies extrapolation and intraspecies variability. Diflubenzuron has been reviewed by the FAO/WHO joint committee on pesticide residues and an Acceptable Daily Intake (ADI) of 0.02 mg/kg/ day was established in 1985. The ADI was based upon the 1- year oral toxicity study in dogs with a NOAEL of 2.0 mg/kg/day, with a safety factor of 100 applied to account for inter- and intra- species variability. 4. Carcinogenicity. Based on the available evidence, which included adequate carcinogenicity studies in rats and mice, and a battery of negative mutagenicity studies, diflubenzuron per se has been classified as Group E (evidence of non- carcinogenicity for humans). However, p- chloroaniline (PCA), a metabolite of diflubenzuron, was classified as a Group B2 carcinogen (probable human carcinogen). The classification for PCA was based on the results of a National Toxicology Program (N.T.P.) study reported in July 1989, in which PCA-HCL was administered by gavage to rats and mice for 2 years. In rats, clearly increased incidences of uncommon sarcomas (fibrosarcomas, hemangiosarcomas, and/ or osteosarcomas) of the spleen were observed in males. In females, two additional sarcomas of the spleen were also found. Pheochromocytomas of the adrenal gland may also have been associated with the test material in male and female rats. In mice, increased incidences of hepatocellular neoplasms in the liver and of hemangiosarcomas in the spleen and/or liver were observed in males. In females, no evidence of carcinogenic activity was observed. The results of several mutagenicity studies on PCA were also included in the same N.T.P. Report. PCA was mutagenic in Salmonella strains TA98 and TA100 with metabolic activation. Gene

mutations were induced by PCA in cultured mouse lymphoma cells with and without metabolic activation. In cultured Chinese Hamster Ovary (CHO) cells, treatment with PCA produced significant increases in sister chromatic exchanges (SCEs) with and without metabolic activation. Chromosomal aberrations were also significantly increased in CHO cells in the presence of metabolic activation. For the purpose of calculating dietary risk assessments, the following procedure was used: i. P-chlorophenylurea (CPU) and p-chloroacetanilide (PCAA), additional metabolites of diflubenzuron that are closely related to PCA and for which there are no adequate carcinogenicity data available, should be considered to be potentially carcinogenic and to have the same carcinogenic potency (Q1*) as PCA. ii. The sum of PCA, CPU, and PCAA residues in ingested food should be used to estimate the dietary exposure of humans to the carcinogenic metabolites of diflubenzuron. iii. In addition to ingested residues of these three metabolites, amounts of PCA, CPU, and/or PCAA formed in vivo following ingestion of diflubenzuron should also be included when estimating the total exposure of humans to the carcinogenic metabolites of diflubenzuron. The in vivo conversion of ingested diflubenzuron to PCA and/or CPU was estimated to be 2.0%, based on data in the rat metabolism study. The Q1* (estimated unit risk) for PCA, based upon spleen sarcoma rates in male rats, was calculated to be 6.38 x 10-2 (mg/kg/day)-1 in human equivalents. It has been determined that PCAA does not occur in animal or plant tissues in significant amounts.

C. Exposures and Risks

1. From food and feed uses. Tolerances have been established (40 CFR 180.377) for the residues of diflubenzuron per se, in or on citrus, artichokes, walnuts, mushrooms, cottonseed, soybean, rice, and associated livestock commodities. Existing tolerances range from 0.05 ppm in/on soybeans, to 6.0 ppm in/on artichokes. Tolerances of 0.05 ppm have also been established for residues of diflubenzuron in animal commodities. Risk assessments were conducted by EPA to assess dietary exposures and risks from diflubenzuron as follows: i. Acute exposure and risk. Acute dietary 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. One day single dose oral studies in rats and mice indicated only marginal effects on methemoglobin levels at a dose level of 10,000 mg/kg/day. Therefore, this risk assessment is not needed, as there are no significant acute effects observed. ii. Chronic exposure and risk. For conducting the chronic dietary risk assessment, refined residue estimates were used for all commodities except for pears. Percent of crop treated figures were also used for certain commodities. The percent of RfD utilized for Non- Nursing Infants -7, which does not exceed EPA's levels of concern. The DWLOC for cancer risk for the U.S. population is 0.26 ppb. Estimated drinking water concentrations from PCA/CPU (0.73 ppb) are greater than the DWLOC of 0.26, for cancer risk. However, EPA believes these estimates are significantly overstated for several reasons. The PRZM/ EXAMS model used to derive these estimates was designed for ecological risk assessments, and uses a scenario of a body of water approximating the size of a 2.5 acre pond. This tends to overstate chronic drinking water exposure levels for the following reasons. First, surface water source drinking water generally comes from bodies of water that are substantially larger. Second, the scenario assumes that the whole basin receives an application of the pesticide, but in virtually all cases, basins used for drinking water will contain a substantial portion of the area that does not receive pesticide application. Third, there is often at least some flow or turnover of the water, so the persistence of the pesticide near the drinking water facility is usually overestimated. Fourth, even assuming that the reservoir is directly adjacent to an agricultural field, the field may not be used to grow a crop on which the pesticide in question is registered for use. Fifth, the PRZM/EXAMS scenario does not take into account reductions in residue-loading due to applications less than the maximum application rate or no treatment of the crop at all. Considering these uncertainties associated with the modeled water estimates noted above, and the fact that the estimated concentrations are within close range of the DWLOCs, EPA concludes with reasonable certainty that residues of diflubenzuron in drinking water will

not contribute significantly to the aggregate cancer human health risk. 5. Determination of safety. Based on these risk assessments, EPA concludes that there is a reasonable certainty that no harm will result from aggregate exposure to diflubenzuron residues.

E. Aggregate Risks and Determination of Safety for Infants and Children

1. Safety factor for infants and children-- i. In general. In assessing the potential for additional sensitivity of infants and children to residues of diflubenzuron, EPA considered data from developmental toxicity studies in the rat and rabbit and a 2-generation reproduction study in the rat. The developmental toxicity studies are designed to evaluate adverse effects on the developing organism resulting from maternal pesticide exposure during gestation. Reproduction studies provide information relating to effects from exposure to the pesticide on the reproductive capability of mating animals and data on systemic toxicity. FFDCA section 408 provides that EPA shall apply an additional tenfold margin of safety for infants and children in the case of threshold effects to account for pre- and post-natal toxicity and the completeness of the data base unless EPA determines that a different margin of safety will be safe for infants and children. Margins of safety are incorporated into EPA risk assessments either directly through use of a margin of exposure (MOE) analysis or through using uncertainty (safety) factors in calculating a dose level that poses no appreciable risk to humans. EPA believes that reliable data support using the standard MOE and uncertainty factor (usually 100 for combined inter- and intra-species variability) and not the additional tenfold MOE/uncertainty factor when EPA has a complete data base under existing guidelines and when the severity of the effect in infants or children or the potency or unusual toxic properties of a compound do not raise concerns regarding the adequacy of the standard MOE/safety factor. ii. Developmental toxicity studies. In the developmental study in rats, the maternal (systemic) and the developmental (fetal) NOAEL were both 1,000 mg/kg/day. No LOAELs were achieved, as no maternal or developmental toxicity was observed. In the developmental toxicity study in rabbits, both the maternal (systemic) and the developmental (fetal) NOAELs were both 1,000 mg/kg/ day. As with the rat study, mentioned above, no LOAELs were achieved, as no maternal or developmental toxicity was observed. iii. Reproductive toxicity study. In the 2-generation reproductive toxicity study in rats, the parental (systemic) NOAEL was considered to be less than 36 mg/kg/day for males, and less than 42 mg/kg/day for females based on hematological effects at all dose levels tested. For offspring effects, the NOAEL was equal to 427 mg/kg/day, and the LOAEL was equal to 4,254 mg/kg/day, based on statistically significant decreases in F-1 pup weight on days 4, 8, and 21 of lactation. iv. Pre- and post-natal sensitivity. The toxicological database for evaluating pre- and post-natal toxicity for diflubenzuron is completed with respect to current data requirements. There are no pre- or post- natal toxicity concerns for infants and children, based upon the result of the developmental and reproductive studies mentioned above. v. Conclusion. The OPP FQPA Safety Factor Committee recommended that the 10X factor for increased susceptibility of infants and children be reduced to 1X, for diflubenzuron. This decision was based on the determination that there was no indication of increased susceptibility of rats or rabbits to in utero and/or postnatal exposure to diflubenzuron, and because exposure assessments do not indicate a concern for potential risk to infants and children. There is a complete toxicity database for diflubenzuron and exposure data is complete or is estimated based on data that reasonably accounts for potential exposures. 2. Acute risk. Since one day single dose oral studies in rats and mice indicated only marginal effects, this risk assessment is not needed, as there are no significant acute effects observed. 3. Chronic risk. Using the exposure assumptions described in this unit, EPA has concluded that aggregate exposure to diflubenzuron from food will utilize 6.1% of the RfD for Non-Nursing Infants tompkins.jim@epa.gov, or by mailing a request for information to Mr. Tompkins at Registration Division (7505C), Office of Pesticide Programs, Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. If you would like to request a waiver of the tolerance objection fees, you must mail your request for such a waiver to: James Hollins, Information Resources and Services Division (7502C), Office of Pesticide Programs, Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. 3. Copies for the Docket. In addition to filing an objection or hearing request with the Hearing Clerk as described in Unit VII.A. of this preamble, you should also send a copy of your request to the PIRIB for its inclusion in the official record that is described in Unit I.B.2. of this preamble. Mail your copies, identified by the docket number OPP-300921, to: Public Information and Records Integrity Branch, Information Resources and Services Division (7502C), Office of Pesticide Programs, Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. In person or by courier, bring a copy to the location of the PIRIB described in Unit I.B.2. of this preamble. You may also send an electronic copy of your request via e-mail to: opp- docket@epa.gov. Please use an ASCII file format and avoid the use of special characters and any form of encryption. Copies of electronic objections and hearing requests will also be accepted on disks in WordPerfect 5.1/6.1 file format or ASCII file format. Do not include any CBI in your electronic copy. You may also submit an electronic copy of your request at many Federal Depository Libraries.

B. When Will the Agency Grant a Request for a Hearing?

A request for a hearing will be granted if the Administrator determines that the material submitted shows the following: There is a genuine and substantial issue of fact; there is a reasonable possibility that available evidence identified by the requestor would, if established resolve one or more of such issues in favor of the requestor, taking into account uncontested claims or facts to the contrary; and resolution of the factual issues(s) in the manner sought by the requestor would be adequate to justify the action requested (40 CFR 178.32).

VIII. Regulatory Assessment Requirements

This final rule establishes a tolerance under section 408 of the FFDCA. 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). 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., or 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). Nor does it require prior consultation with State, local, and tribal government officials as specified by Executive Order 12875, entitled Enhancing the Intergovernmental Partnership (58 FR 58093, October 28, 1993) and Executive Order 13084, entitled Consultation and Coordination with Indian Tribal Governments (63 FR 27655, May 19,1998), or special consideration of environmental justice related issues under Executive Order 12898, entitled Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations (59 FR 7629, February 16, 1994), or require OMB review in accordance with Executive Order 13045, entitled Protection of Children from Environmental Health Risks and Safety Risks (62 FR 19885, April 23, 1997). The Agency has determined that this action will not have a substantial direct effect on 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, as specified in Executive Order 12612, entitled Federalism (52 FR 41685, October 30, 1987). This action directly regulates growers, food processors, food handlers and food retailers, not States. This

action does not alter the relationships or distribution of power and responsibilities established by Congress in the preemption provisions of the FFDCA, 21 U.S.C. 346a(n)(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). In addition, since tolerances and exemptions that are established under FFDCA section 408(l)(6), such as the tolerance in this final rule, do not require the issuance of a proposed rule, the requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et seq.) do not apply.

IX. Submission to Congress and the Comptroller General

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report, which includes a copy of the rule, 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 rule in the Federal Register. This rule is not a ``major rule'' as defined by 5 U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

Environmental protection, Administrative practice and procedure, Agricultural commodities, Pesticides and pests, Reporting and recordkeeping requirements.

Dated: September 14, 1999 .

Peter Caulkins,

Acting Director, Registration Division, Office of Pesticide Programs. Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

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

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

2. In Sec. 180.377, by adding text to paragraph (b) to read as follows:

Sec. 180.377 Diflubenzuron; tolerances for residues.

* * * * * (b) Section 18 emergency exemptions. Time-limited tolerances are established for residues of diflubenzuron and its metabolites, PCA (4- chloroaniline) and CPU (4-chlorophenylurea), expressed as the parent diflubenzuron, in connection with use of this pesticide under a section 18 emergency exemption granted by EPA. The tolerances will expire on the dates specified in the following table.

------------------------------------------------------------------------ Expiration/ Commodity Parts per million revocation date ------------------------------------------------------------------------ Pears........................... 0.5 3/31/00 ------------------------------------------------------------------------

* * * * *

[FR Doc. 99-25312 Filed 9-28-99; 8:45 am] BILLING CODE 6560-50-F