August 8, 2001 Mr. Anthony Britten Special Review and Reregistration Division Office of Pesticide Programs (7508C) U. S. Environmental Protection Agency Room 266A, Crystal Mall 2 1921 Jefferson Davis Highway Arlington, Virginia 22202 Corr. # daL075 01 Dear Mr. Britten,

Re: Carbaryl; Chemical number 56801; EPA Reg. No. 264 324 Review of the Preliminary Risk Assessments for Human Health and for Environmental Fate and Ecological Effects for the Reregistration Eligibility Decision on Carbaryl We have completed our review of the preliminary human health and environmental fate and ecological effects risk assessments for the Reregistration Eligibility Decision of carbaryl. Our comments on the Agency's assessments are enclosed in the following documents:   Review of the Draft Human Health Risk Assessment   Review of the Draft Environmental Fate and Ecological Risk Assessment for the Reregistration of Carbaryl Hard copies of the above documents will be sent by express mail within the next week.

Key issues discussed in these documents are as follow:

DRAFT HUMAN HEALTH RISK ASSESSMENT FQPA Considerations A 2 Generation reproduction study was recently completed and submitted to the Agency. The No Observable Effect Levels (NOELs) for carbaryl administered in the diet, in CD® (SD) rats under the conditions of this study, were:

° For parental systemic toxicity: 75 ppm ° For parental reproductive toxicity: 1500 ppm ° For offspring toxicity: 75 ppm In addition, Aventis has submitted to the EPA a revised Developmental Neurotoxicity Study (DNT) which demonstrated that no alterations in brain morphometric measurements were observed in the offspring, thus no increased sensitivity was observed in the pups.

Aventis firmly believes that with the submission of these two studies, the data gap for the 2 generation reproduction study is fulfilled and the issue with the developmental neurotoxicity study is resolved. Thus, the Agency has the required data to justify removing the extra 10X FQPA Safety Factor from the risk calculations throughout the Human Health Risk Assessment for carbaryl. Mr. Anthony Britten August 8, 2001 Page 2 Additional Uncertainty Factors For the chronic study in dogs, Aventis does not agree with the additional 3X for a lack of a NOEL in the study. According to the policy issued in August 2000 concerning the endpoint for selection for cholinesterase inhibiting compounds, the Agency stated that the red blood cell (RBC) inhibition should be used instead of the plasma. The NOEL for RBC cholinesterase inhibition was 125 ppm (3.1 mg/ kg/ day). Additionally, Aventis believes that the brain cholinesterase inhibition observed at the 125 ppm level was slightly above background level and was not of toxicological concerns due to the lack of clinical signs observed at this dose level. Furthermore, Aventis performed a five week study in dogs, which agreed with the results of the chronic study. Therefore, it is our opinion that all calculations based on the chronic dog in the document should be adjusted to reflect the removal of the 3X safety factor.

Cancellation of Certain Uses of Carbaryl Use on Barley, Oats, Rye, and Cotton: Changes should be made throughout the Human Health Risk Assessment and associated supporting documents to reflect the cancellation of the use on barley, oats, rye, and cotton. It should be noted that Aventis CropScience labels for the technical materials and the end use products containing carbaryl were amended to delete these uses. The Agency has already approved the labeling changes.

Use on Poultry: Aventis CropScience will no longer support the use of carbaryl for direct application to poultry, as well as the poultry quarters treatment. We will submit a request for cancellation of these uses in accordance with section 6( f)( 1) of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). The cancellation of this use causes a significant improvement in the risk assessment since poultry are the major contributor to the risk estimate. We believe that only the dietary analyses conducted without poultry should be included in the HED Chapter. Analyses including poultry would be unrealistic and misleading.

Dietary Exposure Assessment An industry sponsored Carbamate Market Basket Survey (CMBS) was conducted and submitted to the Agency for use in the dietary exposure and risk assessment for carbaryl. The Carbamate Market Basket Survey Task Force met with EPA/ HED before the start of the study to review the purpose and design of the study. The EPA assured the task force that the study data would be used in risk assessments, taking precedence over all other monitoring or field trial data available for those crops. A surrogation plan according to HED SOP 99.3 was also assured. These data provide more realistic measures of residues to which consumers are exposed and they should be included in the dietary analyses as agreed upon by the CMBS Task Force and the EPA.

Water Exposure Assessment EPA has based its assumptions about concentrations of carbaryl in drinking water upon model simulations. Aventis CropScience conducted a drinking water monitoring program that provides the best estimate of concentrations of carbaryl in drinking water. The study uses the sampling design for acute endpoints recommended in industry/ EPA meetings during 1999 (weekly sampling during times of peak concentrations over a three year period). Twenty sites, representative of the most vulnerable community water systems in the highest use areas of carbaryl, were selected. These included 16 sites in agricultural areas and 4 locations in urban areas. Samples were collected from the inlet and outlet water at each sampling interval. Outlet samples were only analyzed when residues were present in the inlet samples. The analytical method has a limit of quantification of 0.030 ppb and a limit of detection of 0.002 ppb.

The study provides information on concentrations of carbaryl in community water systems most likely to contain the highest concentrations of carbaryl. Residues of carbaryl in other areas would be expected to be Mr. Anthony Britten August 8, 2001 Page 3 lower. The study should be used in the carbaryl exposure calculations as it provides the drinking water concentrations needed for FQPA dietary assessments.

Occupational and Residential Exposure Assessment Aventis CropScience has conducted, or is in the process of conducting, studies relevant to the refinement of the occupational and residential risk assessment. These studies are as follows:

Study Anticipated Completion Date

4 Week Repeated Dose Dermal Toxicity Study with SEVIN ® XLR Plus in Rats. September 2001

4 Week Repeated Dose Dermal Toxicity Study with SEVIN ® 80S in Rats. September 2001

4 Week Repeated Dose Dermal Toxicity Study with Carbaryl Technical in Rats. September 2001

Measurement of Pesticide Exposure of Suburban Residents Associated with the Residential Use of Carbaryl. March 2002

Biological monitoring of citrus orchard application and post application apple thinning and cherry harvesting job functions March 2002 DRAFT ENVIRONMENTAL FATE AND ECOLOGICAL RISK ASSESSMENT Carbaryl Studies to Fulfill Requirements Aventis CropScience is in the process of conducting, or has scheduled, studies relevant to the refinement of the environmental risk assessments for carbaryl and the major degradate 1 naphthol. These studies are as follows:

  Rate and Route of Aerobic Degradation in Soils. These studies have been initiated with parent carbaryl applied to four diverse U. S. soils. The data are intended to provide additional half life determinations for parent carbaryl and the major degradate 1 naphthol. Expected completion date: March 2002   Aerobic Aquatic Metabolism in Two Water/ Sediment Systems. These studies have been initiated with parent carbaryl applied to two distinct U. S. water/ sediment systems. The data are intended to provide additional half life determinations for parent carbaryl and the major degradate 1 naphthol. In addition, further identification of additional degradation products is anticipated. Expected completion date: March 2002 Mr. Anthony Britten August 8, 2001 Page 4   Adsorption and Desorption of 1 Napthol to five soils. This study has been scheduled to evaluate the adsorption and desorption of the major carbaryl degradate to five soils/ sediment. The data are intended to provide information necessary to evaluate the environmental risks from 1 naphthol in standard models. Expected completion date: March 2002 For the reregistration process in the EU, Aventis CropScience is in the process of conducting, or has scheduled, studies relevant to the refinement of the ecotoxicological risk assessments for carbaryl and the major degradate 1 naphthol. These studies are as follows:

  Studies with Carbaryl: Acute oral LD50 in mallard ducks Dynamic acute LC50 in bluegill sunfish Acute toxicity in Daphnia Acute toxicity in Chironomus riparius Toxicity in Selenastrum capricornutum Acute oral and contact toxicity in honeybees 14 d toxicity in earthworms Effects on soil microorganisms (nitrification/ carbon cycle) Effect on sewage treatment   Studies with 1 naphthol Early life stage study in fathead minnows Acute toxicity in Daphnia Acute toxicity in Daphnia in presence of sediment Chronic toxicity in Daphnia 14 d toxicity in earthworms   Formulated Product Vegetative Vigor Toxicity in Selenastrum capricornutum Acute oral and contact toxicity in honeybees Effect on non target arthropods 14 d toxicity in earthworms Effects on soil microorganisms (nitrification/ carbon cycle)

Ecotoxicological Risk Assessments Aventis has pointed out several errors in the PRZM input parameters (see comments made to Tables 5 and 6 of the draft RED). Overly conservative estimates of foliar dissipation half lives and changes in ecotoxicology study endpoints would dictate a re calculation of the EECs and risk quotients is warranted in a number of instances. Mr. Anthony Britten August 8, 2001 Page 5 Endocrine Disruption Reports in the open literature on the reproductive effects of carbaryl in wild mammals are at best ambivalent. The recently submitted 2 generation study in rats demonstrates the absence of reproductive effects. As EPA pointed out, findings reported in the literature were made at concentrations well above the highest peak concentration modeled. Therefore these findings are irrelevant for a risk assessment and at the current stage of discussion about endocrine disruption. If the concern about the endocrine potential of carbaryl persists, the issue should be revisited once the Agency's endocrine disrupter screening and testing program as well as a policy on how to incorporate positive findings into an ecological risk assessment have been fully developed.

Mobility The classification of carbaryl as mobile to very mobile is inconsistent with measured Koc values of 177 to 249 (MRID 43259301). According to the widely used classification scheme of McCall, et al. (1980) wherein Koc values between 150 and 500 denote medium mobility in soil, carbaryl would be classified as having medium mobility in most soils. This classification of medium mobility is further supported by the acceptable column leaching study (MRID 43320701) in which aged carbaryl residues were only slightly mobile in a number of soils. The mobility of carbaryl would be expected to be higher in sandy soils or in soils of low organic matter.

1 Napthol Fate and Transport The Agency is requiring additional information on the persistence and mobility of 1 naphthol, a major environmental degradate of carbaryl. However, a half life for 1 naphthol of less than 1 day can be calculated from the carbaryl aerobic soil metabolism study (MRID 42785101). The data from this study demonstrate that under aerobic soil conditions the formation and decline of 1 naphthol, starting from parent carbaryl, is complete in less than 14 days. This half life can be used for preliminary environmental fate modeling to estimate EECs for 1 naphthol.

The EPA suggested that 1 naphthol is not strongly sorbed to soil. Additional information available in the literature demonstrates that the sorption of 1 naphthol to soil is stronger than that seen for carbaryl itself. Hassett et al. (1981) has demonstrated that the sorption of 1 naphthol was the result of sorption to organic carbon resulting in Koc values between 431 and 15,618. These data indicate that 1 naphthol is less mobile and less susceptible to leaching than carbaryl itself, and they demonstrate that at least a portion of the 1 naphthol residue is tightly sorbed to soil constituents. To meet the requirement for information on the adsorption and desorption of 1 naphthol by the Agency, the registrant is conducting an adsorption/ desorption study to meet the 163 1 guideline. Study results should be available for submission to the Agency in the first quarter of the calendar year 2002.

Ground Water EPA summarized information on the detection of carbaryl in groundwater from the EPA Pesticides in Groundwater Database, the EPA STORET database and the NAWQA database. Each of the databases shows a pattern of very low levels of carbaryl detection in few groundwater resources. These analyses confirm several statements made by the Agency that carbaryl have limited potential to impact groundwater resources. However, on page 2 of the Memorandum issued June 28, 2001, in conjunction with the EFED RED chapter for carbaryl, EPA is requiring additional information on "Surface and groundwater monitoring in urban and suburban use areas (non guideline)." Based on the characteristics of carbaryl and the available data demonstrating limited impact of carbaryl on ground water resources, additional studies to evaluate the potential for carbaryl to contaminate groundwater are unnecessary and unwarranted. Mr. Anthony Britten August 8, 2001 Page 6 Please let me know if you need any additional information. My phone number is (919) 549 2718.

Sincerely,

Danielle A. Larochelle Danielle A. Larochelle Registration Manager 1 CARBARYL Chemical ID No. 056801; Case 0080 Review of the Draft Human Health Risk Assessment August 8, 2001 Aventis CropScience P. O. Box 12014, 2 T. W. Alexander Drive Research Triangle Park, NC 27709 2 TABLE OF CONTENTS GENERAL COMMENTS ........................................................................................................ 3 FQPA Considerations ......................................................................... 3 Additional UncertaintyFactors ........................................................... 3 Cancellation of Certain Uses of Carbaryl ........................................... 3 Dietary Exposure Assessment ............................................................ 4 Water Exposure Assessment .............................................................. 4 Occupational and Residential Exposure Assessment ......................... 4 PART I  TOXICOLOGY DATA BASE ................................................................................... 6 Line by Line Review of the Toxicology Data Base Evaluation from the Human Health Risk Assessment Document for Carbaryl (June 19, 2001) ........................................................................ 6 PART I  TOXICOLOGY DATA BASE .................................................................................. 20 SUPPORTING DISCUSSIONS ....................................................... 20 PART II  DIETARY AND WATER EXPOSURE/ RISK ASSESSMENT ...................................... 32 Line by Line Review of the Dietary and Water Exposure Assessment of the Human Health Risk Assessment Document for Carbaryl (June 19, 2001) ...................................................................... 32 Line by Line Review of the Supporting Document "Revised Dietary Exposure Analysis for the HED Revised Human Health Risk Assessment (Felicia A. Fort; April 26, 2001)" ...................... 40 PART II  DIETARY AND WATER EXPOSURE/ RISK ASSESSMENT ...................................... 44 SUPPORTING DISCUSSIONS ....................................................... 44 PART III  RESIDUE CHEMISTRY CONSIDERATIONS .......................................................... 51 Line by Line Review of the Residue Chemistry Information Included in the Human Health Risk Assessment Document for Carbaryl (June 19, 2001) ...................................................................... 51 Line by Line Review of the Supporting Document "Product and Residue Chemistry Chapters for the Reregistration Eligibility Decision (Felecia Fort; November 14, 2000)" ...................... 53 Line by Line Review of the Supporting Document "Carbaryl: Occupational and Residential Exposure Assessment and Recommendations for the Reregistration Eligibility Decision Document (Jeffrey L. aDawson; June 28, 2001)" .................. 59 PART IV  OCCUPATIONAL AND RESIDENTIAL EXPOSURE/ RISK ASSESSMENT ............... 64 SUPPORTING DISCUSSION ......................................................... 64 APPENDIX I ................................................................................................................... 66 3 General Comments FQPA Considerations A 2 Generation reproduction study was recently completed and submitted to the Agency. The No Observable Effect Levels (NOELs) for carbaryl administered in the diet, in CD® (SD) rats under the conditions of this study, were: ° For parental systemic toxicity: 75 ppm ° For parental reproductive toxicity: 1500 ppm ° For offspring toxicity: 75 ppm In addition, Aventis has submitted to the EPA a revised Developmental Neurotoxicity Study (DNT) which demonstrated that no alterations in brain morphometric measurements were observed in the offspring, thus no increased sensitivity was observed in the pups.

Aventis firmly believes that with the submission of these two studies, the data gap for the 2 generation reproduction study is fulfilled and the issue with the developmental neurotoxicity study is resolved. Thus, the Agency has the required data to justify removing the extra 10X FQPA Safety Factor from the risk calculations throughout the Human Health Risk Assessment for carbaryl.

Additional UncertaintyFactors For the chronic study in dogs, Aventis does not agree with the additional 3X for a lack of a NOEL in the study. According to the policy issued in August 2000 concerning the endpoint for selection for cholinesterase inhibiting compound, the Agency stated that the red blood cell (RBC) should be used instead of the plasma. The NOEL for RBC cholinesterase inhibition was 125 ppm (3.1 mg/ kg/ day). Additionally, Aventis believes that the brain cholinesterase inhibition observed at the 125 ppm level was slightly above background level and was not of toxicological concerns due to the lack of clinical signs observed at this dose level. Furthermore, Aventis performed a five week study in dogs, which agreed with the results of the chronic study. Therefore, it is our opinion that all calculations based on the chronic dog in the document should be adjusted to reflect the removal of the 3X safety factor.

Cancellation of Certain Uses of Carbaryl Use on Barley, Oats, Rye, and Cotton Changes should be made throughout the Human Health Risk Assessment and associated supporting documents to reflect the cancellation of the use on barley, oats, rye, and cotton. It should be noted that Aventis CropScience labels for the technical materials and the end use products containing carbaryl were amended to delete these uses. The Agency has already approved the labeling changes. Please refer to Part III of this document (Residue Chemistry Considerations) for current labeling information. Corrections on label acceptance dates are also provided in Part III. 4 Use on Poultry Aventis CropScience will no longer support the use of carbaryl for direct application to poultry, as well as the poultry quarters treatment. We will submit a request for cancellation of these uses in accordance with section 6( f)( 1) of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). The cancellation of this use causes a significant improvement in the risk assessment since poultry are the major contributor to the risk estimate. We believe that only the dietary analyses conducted without poultry should be included in the HED Chapter. Analyses including poultry would be unrealistic and misleading.

Dietary Exposure Assessment An industry sponsored Carbamate Market Basket Survey (CMBS) was conducted and submitted to the Agency for use in the dietary exposure and risk assessment for carbaryl. The Carbamate Market Basket Survey Task Force met with EPA/ HED before the start of the study to review the purpose and design of the study. The EPA assured the task force that the study data would be used in risk assessments, taking precedence over all other monitoring or field trial data available for those crops. A surrogation plan according to HED SOP 99.3 was also assured. These data provide more realistic measures of residues to which consumers are exposed and they should be included in the dietary analyses as agreed upon by the CMBS Task Force and the EPA.

Water Exposure Assessment EPA has based its assumptions about concentrations of carbaryl in drinking water upon model simulations. Aventis CropScience conducted a drinking water monitoring program that provides the best estimate of concentrations of carbaryl in drinking water. The study uses the sampling design for acute endpoints recommended in industry/ EPA meetings during 1999 (weekly sampling during times of peak concentrations over a three year period). Twenty sites, representative of the most vulnerable community water systems in the highest use areas of carbaryl, were selected. These included 16 sites in agricultural areas and 4 locations in urban areas. Samples were collected from the inlet and outlet water at each sampling interval. Outlet samples were only analyzed when residues were present in the inlet samples. The analytical method has a limit of quantification of 0.030 ppb and a limit of detection of 0.002 ppb.

The study provides information on concentrations of carbaryl in community water systems most likely to contain the highest concentrations of carbaryl. Residues of carbaryl in other areas would be expected to be lower. The study should be used in the carbaryl exposure calculations as it provides the drinking water concentrations needed for FQPA dietary assessments.

Occupational and Residential Exposure Assessment Aventis CropScience has conducted, or is in the process of conducting, studies relevant to the refinement of the occupational and residential risk assessment. These studies are as follows: 5 Study Anticipated Completion Date

4 Week Repeated Dose Dermal Toxicity Study with Sevin   XLR Plus in Rats. September 2001

4 Week Repeated Dose Dermal Toxicity Study with Sevin   80S in Rats. September 2001

4 Week Repeated Dose Dermal Toxicity Study with Carbaryl Technical in Rats. September 2001

Measurement of Pesticide Exposure of Suburban Residents Associated with the Residential Use of Carbaryl. March 2002

Biological monitoring of citrus orchard application and postapplication apple thinning and cherry harvesting job functions March 2002 6 Part I  Toxicology Data Base Line by Line Review of the Toxicology Data Base Evaluation from the Human Health Risk Assessment Document for Carbaryl (June 19, 2001)

1.0 Executive Summary Section Number 1.0 Page: 3 Paragraph: 4 Line: 3 EPA comment: In the developmental neurotoxicity study in the rat, alterations in brain morphometric measurements were observed in offspring.

Aventis' response: Aventis has submitted to EPA a revised DNT, which demonstrated no alterations in brain morphometric measurements taken in the offspring, thus no increased sensitivity was observed in the pups. The details of this study will be discussed below in the supporting `Discussion Section'.

Page: 3 Paragraph: 5 Line: 3 EPA comment: No acceptable two generation reproduction study is available.

Aventis' response: Aventis has submitted to EPA a new 2 Generation Reproduction Study with carbaryl, which neither demonstrated that carbaryl is a reproductive toxicant nor demonstrated that the pups were more sensitive than the dams. The NOELs for carbaryl administered in the diet, in CD® (SD) rats under the conditions of this study were: ° For parental systemic toxicity: 75 ppm ° For parental reproductive toxicity: 1500 ppm ° For offspring toxicity: 75 ppm The details of this study will be discussed below in the supporting `Discussion Section'.

Page: 3 continued on page 4 Paragraph: 5 Lines: 4 7 EPA comment: In the developmental neurotoxicity study, maternal toxicity was observed at the same dose as changes in brain morphometric measurements in offspring; however, these brain measurements were not performed at the next lower dose and consequently, there is some uncertainty about the NOAEL for this effect. 7 Aventis' response: As stated above, Aventis has submitted to EPA a revised DNT, which demonstrated no alterations in brain morphometric measurements taken in the offspring, thus no increased sensitivity was observed in the pups. The details of this study will be discussed below in the supporting `Discussion Section'.

Page: 4 Paragraph: 5  continuation from page 3 Lines: 2 9 EPA comment: The 10x Food Quality Protection Act (FQPA) Safety Factor has been retained because: 1) the toxicology data base is incomplete; there is a data gap for the multi generation reproduction study in rats; 2) an assessment of susceptibility following pre/ post natal exposure to carbaryl could not be made due to the data gap for the reproduction study; 3) there is concern for the results of the developmental neurotoxicity study (uncertainty about NOAEL). Based on these considerations, the 10x safety factor was applied to all population subgroups in assessing risks from acute and chronic dietary exposures and residential exposures of all durations.

Aventis' response: As stated above, Aventis has submitted to EPA a revised DNT and a new 2 Generation Reproduction Study that has a direct impact on the FQPA Safety Factor. Aventis firmly believes that with the submission of these two studies, the data gap for the 2 generation reproduction study will be fulfilled and the NOEL question for the DNT will be resolved. Thus, the Agency has the required data to reduce the FQPA Safety Factor from 10X to 1X.

Page: 4 Paragraph: 1 Lines 1 6: EPA comment: Carbaryl has been classified as a Group C possible human carcinogen based on an increased incidence of hemangiosarcomas and combined hemangiomas/ hemangiosarcomas in CD 1 mice at 1000 ppm (146 mg/ kg/ day) and above. Mechanistic metabolism studies and a study in heterozygous p53 deficient mice were considered inadequate to demonstrate a mode of action for the vascular tumors. The default linear low dose extrapolation was used for risk assessment; the Q1* is 1.19 x 10 2 (mg/ kg/ day) 1 based on the mouse vascular tumors.

Aventis' response: Aventis strongly believes that the use of carbaryl products presents no imminent carcinogenic risk to users based on the following points:

  Current data support a hypothesis that high doses of carbaryl in life time studies produce tumors via a non genotoxic mechanism, possibly related to altered metabolism at these high doses. 8   At doses less than the MTD, there was an increased incidence of tumors only in 1 site of 1 sex of 1 species.

  The increased incidence of vascular tumors in the male mice after two years of administration is of questionable biological significance.

  In the p53 knockout mouse model, which was demonstrated, to be sensitive to the induction of vascular tumors by a genotoxic reference compounds, carbaryl was found to be negative.

  The weight of the evidence indicates that carbaryl shows no potential for genotoxicity   Epidemiological data on carbaryl production workers show no increase in tumor incidence.

In the two year bioassay conducted in the CD1 mouse, a statistically significantly higher incidence of vascular tumors was noted in males at 1,000 and 8,000 ppm. In females, no statistically significant change in the incidence of vascular tumors was observed. The overall incidence of vascular tumors was 2, 6, 10 and 10 in males and 3, 3, 4 and 9 in females at 0, 100, 1,000 and 8,000 ppm, respectively.

In order to address the biological significance of the vascular tumors, the p53 knockout mouse model was used as a tool to study chemical carcinogenesis (Donehower, 1996). The p53 mouse is a genetically manipulated mouse in which one allele of the p53 tumor suppresser gene has been inactivated. One of the assumptions with the knockout model is that a mutation at the intact p53 allele is necessary for the development of the carcinogenic process. In principle nongenotoxic compounds, which induce tumors by other mechanisms should not induce tumors in this system. The p53 knockout mouse model was validated by testing two compounds: urethane, a genotoxic compound known to produce vascular tumors in standard carcinogenicity bioassays, and d limonene, which is neither genotoxic nor carcinogenic in mice but which is known to be carcinogenic in the male rat by a well described non genotoxic mechanism. In the validation study, the p53 model proved to be very efficient for the induction of vascular tumors by genotoxic compounds (Bigot, 1999; Carmichael et al. 1999). Therefore, this model will produce an unambiguous response to specifically identify genotoxic compounds.

Therefore, carbaryl was tested in the p53 mouse. The objectives of the studies were to evaluate if carbaryl would induce vascular tumors in this model and to set a NOEL in this sensitive and specific model. Additionally, this model provides evidence that the tumors observed in the standard carcinogenicity bioassays resulted from an indirect genotoxic effect. 9 Carbaryl was administered continuously via the diet to groups of 20 male heterozygous p53 knockout mice at concentrations of 0, 10, 30 100, 300, 1,000 and 4,000 ppm for at least 180 days. At the end of the study, all animals were necropsied, selected organs weighed and a range of tissues were taken, fixed and examined microscopically. Carbaryl did not induce mortalities or clinical signs related to the treatment. Only a slight decrease in food consumption during the first eight weeks was observed at 4,000 ppm. This observation was correlated with a lower body weight evolution in comparison with the control animals.

No tumors were found in the 4,000 ppm group. In the other treated groups, a few sporadic tumors were found, but they were clearly unrelated to treatment and representative of the spontaneous tumor types present in mice of this age and strain. In particular, it should be noted that no tumors were found in the liver, kidney or vascular system, which were seen in the original mouse oncogenicity study with carbaryl. The only treatment related non proliferative change observed was the presence of globular deposits in the umbrella cell layer of the urinary bladder at 100 ppm or more.

In conclusion, the data from the p53 studies, the following conclusion can be made:

1). The p53 model was validated with urethane one of the few compound known to induce specifically vascular tumors. 2). Carbaryl was negative, and also did not accelerate the formation of any other tumor types. 3). There is a clear NOEL at 4000 ppm (approximately 716 mg/ kg b. w./ day) in the p53 mouse study for carcinogenicity. 4). Carbaryl is not a genotoxic carcinogen.

Thus the weight of the evidence indicates that carbaryl is not a genotoxic agent in humans. In addition, epidemiological data on carbaryl production workers show no increase in tumor incidence. The two epidemiology studies of Aventis CropScience (formerly Rhône Poulenc and Union Carbide) factory workers representing a sub population of the general public with the highest exposure (i. e., exposure on a daily basis over many years). Thus, the data from these studies represent a potential "worst case" for chronic carbaryl exposure to humans. The results from these studies show that the overall mortality experience of the cohort is significantly less than expected when compared to both United States and West Virginia male death rates. In general, these studies support conclusion that there were no excess cases of cancer in this working population.

A further discussion of this study and the entire carcinogenicity issue will be discussed below in the supporting `Discussion Section'. 10 Page: 4 Paragraph: 2 Lines 5 12: EPA comment: The toxicity endpoints selected for risk assessment are based on neurotoxic effects of ChEI. The dose levels used for the acute and chronic dietary risk assessment, i. e. 10 mg/ kg and 3.1 mg/ kg/ day, were both from studies (acute neurotoxicity study in the rat and chronic toxicity study in the dog, respectively) in which a NOAEL was not determined. Therefore, an additional uncertainty factor of 3x was added to the customary 100x uncertainty factor [10x for extrapolation from animal studies to humans and 10x for intraspecies (human) variation]. The acute and chronic reference doses were 0.03 mg/ kg and 0.01 mg/ kg/ day, respectively.

Aventis' response: Concerning the acute neurotoxicity study in rats, Aventis does not disagree with the Agency's assessment for this endpoint. However, for the chronic study in dogs, Aventis does not agree with the additional 3X for a lack of a NOEL in the study. According to the policy issued in August 2000 concerning the endpoint for selection for cholinesterase inhibiting compound, the Agency stated that the red blood cell (RBC) should be used instead of the plasma. The NOEL for RBC cholinesterase inhibition was 125 ppm (3.1 mg/ kg/ day). Additionally, Aventis believes that the brain cholinesterase inhibition observed at the 125 ppm level are slightly above background level and were not of toxicological concerns due to the lack of clinical signs observed at this dose level. Furthermore, Aventis performed a five week study in dogs, which agreed with the results of the chronic study. Therefore, it is our opinion that all calculations based on the chronic dog in the document should be adjusted to reflect the removal of the 3X safety factor.

Page: 4 Paragraph: 2 Lines 1 6: EPA comment: No dermal or inhalation studies were available.

Aventis' response: As part of the 60 day public comment period, Aventis will be submitting three 21 day dermal studies, which cover the technical material and the formulated products SEVIN® XLR, and SEVIN® 80S. The study results will not be available in time to provide the information to the Agency as part of the 30 day comment period. Similarly, Aventis will be submitting comments for the inhalation requirement as part of the 60 day public comment period. However, it should be noted that in the document titled, "Carbaryl: Toxicology Chapter For RED" the inhalation study was not listed as a data gap on page 25 of that document. 11 Page: 8 Paragraph: 3 Lines 1 10: EPA comment: HED calculated the risks of carbaryl exposure in tobacco. Based on a pyrolysis study submitted by the registrant, residues of carbaryl total approximately 44.58 ppm in tobacco smoke (side stream and main stream combined). Since this is a composited sample of main stream and side stream smoke, it greatly exaggerates the actual exposure to the smoker, whose primary route of exposure is via mainstream smoke. HED further assumed that 100% inhaled is absorbed (i. e., that none of the residue is exhaled along with the smoke). These assumptions result in an extreme overestimate of actual likely exposure. Comparing exposure to the short term inhalation Lowest Observable Adverse Effects Level (LOAEL) of 10 mg/ kg/ day, the short term MOE for carbaryl exposure from the use of tobacco is estimated to be 1000 for males and 900 for females. The MOEs are less than the residential short term inhalation target MOE of 3000 and therefore, the risks exceed HED's level of concern for the general population.

Aventis' response: The relative risk of carbaryl, which is not a genotoxic agent, as compared to the many direct acting genotoxic agents contained in main and side stream smoke is insignificant and is not calculable. The calculation presented by the Agency is crude at best and does not have any impact on the relative risk of smoking cigarettes.

Page: 10 Paragraph: 2 Lines 1 18: EPA comment: HED evaluated reports of human carbaryl poisonings and adverse reactions associated with its use from the following sources: OPP Incident Data System (IDS); Poison Control Centers' Toxic Exposure Surveillance System; California Department of Pesticide Regulation; the National Pesticide Telecommunications Network (NPTN); open literature; and an unpublished study submitted by the registrant. The data from IDS indicated that a majority of cases from carbaryl exposure involved dermal reactions. A number of other cases involved asthmatics and people who experienced hives and other allergic type reactions. It is noted that the dermal sensitization study in the guinea pig was negative. Reports of allergic type reactions in humans could be evidence of a difference in species sensitivity or could be attributable to inert ingredients in the marketed formulations. According to California data, about half have the cases involved skin and eye effects in handlers. About a quarter of the skin reactions were due to workers that were exposed to residues on crops. Reports from the literature are very limited but tend to support the finding that carbaryl has irritant properties. The Poison Control Center cases involving non occupational adults and older children showed an increased risk in five of the six measures used for comparing carbaryl incidents to all other pesticides. The carbaryl cases were almost twice as likely to require serious health care (hospitalization or treatment in a critical care unit) and were two and a half times more likely to experience major medical 12 outcome (life threatening effects or significant residual disability) than other pesticides. This pattern of increased risk was not seen among occupational reports or in young children. This may mean that careless handling by nonprofessionals is a particular hazard.

Aventis' response: As stated by the Agency, reports from the literature are very limited. To draw such conclusions that carbaryl cases were almost twice as likely to require serious health care (hospitalization or treatment in a critical care unit) and were two and a half times more likely to experience major medical outcome (life threatening effects or significant residual disability) than other pesticides is speculative and goes too far in assigning increased frequency values based on limited and often unconfirmed information. The reports cited by the Agency from poison control centers are difficult to interpret because the relative causative agent is frequently not identified. If the agent is identified by officials, the majority of the time it is stated by the officials that the causative agent is merely speculation on their part and that the real agent is not readily known with great certainty.

According to test conducted by Aventis on both technical grade and formulation products, carbaryl is not a skin sensitizer. Furthermore, epidemiological data on carbaryl production workers showed no pattern of skin reaction. This would indicate that if the product is used according to the label, the relative risks of skin reactions to carbaryl are very low.

Page: 10 Paragraph: 3 Lines 1 5: EPA comment: Five case report studies suggested that carbaryl might be a cause of chronic neurological or psychological problems. Some of these effects appear to be consistent with those reported from organophosphate poisoning. However, unlike organophosphates, no controlled studies have been undertaken. If such effects occur as a result of over exposure to carbaryl, they appear to be relatively rare. The effects reported among the five case reports are too inconsistent to draw any conclusions, but do suggest the need for further study.

Aventis' response: Aventis agrees with the Agency that the five case studies cited are weak at best and that the Agency should not be drawing any conclusions based on such inconsistent data. The discussion of such data will lead the reader to draw inappropriate conclusions. Furthermore, epidemiological data on carbaryl production workers showed no such pattern and would indicate that if the product is used according to the label, the relative risks of carbaryl are very low.

Page: 11 Paragraph: 1 Lines 1 3: EPA comment: The epidemiologic study submitted by the registrant compared mortality rates in plant workers exposed to carbaryl to the general population. HED concluded that 13 the sample of workers was too small and the period of follow up too short to permit definitive conclusions.

Aventis' response: Aventis disagrees with the Agency that the mortality rates in plant workers exposed to carbaryl cannot be translated to the general population. The study was statistically designed to specifically address this concern and to examine other non mortality endpoints. The two epidemiology studies of Aventis CropScience (formerly Rhône Poulenc) factory workers representing a sub population of the general public with the highest exposure (i. e., exposure on a daily basis over many years). Thus, the data from these studies represent a potential "worst case" for chronic carbaryl exposure to humans. The results from these studies show that the overall mortality experience of the cohort is significantly less than expected when compared to both United States and West Virginia male death rates. In general, these studies support conclusion that there were no excess cases of cancer in this working population.

Page: 11 Paragraph: 4 Lines 2 4: EPA comment: However, certain key information, which would help refine the risk assessment, is missing. Toxicology data gaps include a reproduction study, a 21 day dermal study in the rat, a 90 day inhalation study in the rat and a micronucleus study.

Aventis' response: The Agency has previously granted a wavier for the in vivo cytogenicity/ micronucleus. Furthermore, Aventis has fulfilled the data requirement for the in vivo mouse micronucleus study. Aventis believes that repeating the in vivo mouse micronucleus study is not appropriate based on the fact that the top dose in the currently submitted mouse micronucleus was 200 mg/ kg/ day and was similar to the mid dose of 250 mg/ kg/ day tested in an acute gavage study in mice. At the 250 mg/ kg dose level tested in the acute study plasma, RBC, and brain cholinesterase inhibition was seen. The percent cholinesterase inhibition observed was 45.7, 45.7, and 57.8, respectively. At the highest dose tested (500 mg/ kg) in the acute study, percent cholinesterase inhibition for plasma, RBC, and brain was 59.8, 57.1, and 66.6, respectively. Additionally, the clinical signs observed at both the 250 and 500 mg/ kg dose levels were very similar in both findings and incidences. Repeating the mouse micronucleus study at a slightly higher dose level would not result in an increase in significant clinical signs. Therefore, the base results of the study concerning clastogenic or aneugenic effects would not change. Carbaryl is not mutagenic for these endpoints.

As previously indicated in this document, Aventis will be submitting three 21 day dermal studies which cover the technical material and for the formulated products SEVIN XLR and SEVIN 80S. Similarly, Aventis will be submitting comments for the inhalation requirement as part of the 60 day public comment period. 14 However, it should be noted that in the document titled, "Carbaryl: Toxiccology Chapter For RED" the inhalation study was not listed as a data gap on page 25 of that document.

Section Number 3.0 Hazard Profile Page: 14 15 Paragraph: 1 Lines: 1 10 EPA comment: The Toxicology Chapter of the RED was prepared by Dr. Virginia Dobozy (D240992 dated December 13, 1999). The toxicology database is of good quality; however, it is incomplete. The following studies are required: two generation reproduction study, 21 day dermal toxicity study with cholinesterase measurements, 90 day inhalation study with cholinesterase measurements and micronucleus study. The lack of a reproduction study and some uncertainty about the findings in offspring in the developmental neurotoxicity study are obstacles to assessing special sensitivity of infants and children and as such, the 10x FQPA Safety Factor was retained. However, the database provides sufficient information for selecting toxicity endpoints for risk assessment and therefore, supports a reregistration eligibility decision for the currently registered uses.

Aventis' response: As stated previously, Aventis has submitted to EPA a revised DNT and a new 2 Generation Reproduction Study, which have a direct impact on the FQPA Safety Factor. Aventis firmly believes that with the submission of these two studies, the data gap for the 2 generation reproduction study is fulfilled and the DNT NOEL question will be resolved. Thus, the Agency has the required data to reduce the FQPA Safety Factor from 10X to 1X. As for the 21 day dermal, 90 day inhalation and mouse micronucleus studies, the need for these studies is addressed in the previous comments made by Aventis.

Page: 17 Paragraph: 1 Lines: 1 6 EPA comment: In the developmental neurotoxicity study, clinical signs of toxicity and plasma and brain ChEI were seen in maternal animals at the same dose (10 mg/ kg/ day) as changes in brain morphometric measurements (decreases in cerebellar measurements in females on Day 11 post partum) were observed in offspring; however, brain measurements were not conducted at the next lower dose. The lowest NOAEL after a single dose administration in adult animals was for maternal animals in the developmental neurotoxicity study, i. e., 1 mg/ kg/ day.

Aventis' response: Aventis has submitted to EPA a revised DNT Study, which demonstrated that no alterations in brain morphometric measurements were observed in the offspring, thus no increased sensitivity was observed in the pups. The details of this study 15 will be discussed below in the supporting `Discussion Section'.

Page: 17 Paragraph: 2 Lines: 1 3 EPA comment: No subchronic studies in the rat or dog are available, except for the subchronic neurotoxicity study in rats. The chronic toxicity data showed that, in dogs, decreases in plasma, RBC and brain ChE were observed at 10 mg/ kg/ day; clinical signs of toxicity were also observed in both sexes.

Aventis' response: For the chronic study in dogs, Aventis does not agree with the additional 3X for a lack of a NOEL in the study. According to the policy issued in August 2000 concerning the endpoint for selection for cholinesterase inhibiting compound, the Agency stated that the RBC should be used instead of the plasma. The NOEL for RBC cholinesterase inhibition was 125 ppm (3.1 mg/ kg/ day). Additionally, Aventis believes that the brain cholinesterase inhibition observed at the 125 ppm level is slightly above background level and was not of toxicological concerns due to the lack of clinical signs observed at this dose level. Furthermore, Aventis performed a five week study in dogs, which agreed with the results of the chronic study. Therefore, it is our opinion that all calculations based on the chronic dog in the document should be adjusted to reflect the removal of the 3X safety factor.

Page: 17 Paragraph: 3 Lines: 1 21 EPA comment: The Health Effects Division's (HED) Cancer Peer Review Committee (CPRC)( 12/ 8/ 93) classified carbaryl as a Group C  possible human carcinogen based on an increased incidence of hemangiosarcomas and combined hemangiomas/ hemangiosarcomas in male mice. Both the low dose extrapolation (Q1*) and margin of exposure (MOE) approaches were proposed for risk assessment. In addition, an RfD approach would be provided to assess the most sensitive non cancer health endpoint for comparison to the linear and MOE approaches. The CPRC requested additional metabolism studies, which could 1) direct the selection of the more appropriate quantitative approach; and 2) provide insight into the significance of the tumors seen only at excessively toxic doses. Additional metabolism studies, including mechanistic studies, were submitted subsequent to the 1993 meeting. A subgroup of the Cancer Assessment Review Committee (CARC) met on September 3, 1998, to review the metabolism studies and concluded that the data from all available metabolism studies were not adequate to support a nonlinear mode of action, as described in the 1996 EPA Proposed Guidelines for Carcinogen Risk Assessment, and therefore recommended that the default linear approach should be used for the cancer risk assessment. The revised Q1*, based on the CD 1 mouse dietary study with ¾ Interspecies Scaling Factor, is 1.19 x 10 2 (mg/ kg/ day) 1 in human equivalents. Subsequently, the registrant submitted a special study in genetically modified mice. Carbaryl was administered to heterozygous p53 deficient (knockout) male mice in the diet at concentrations of up to 4000 ppm (716.6 mg/ kg/ day) for six 16 months. There was no evidence of neoplastic or preneoplastic changes in the vascular tissues of any organ. A model validation study demonstrated that vascular tumors occur in heterozygous p53 deficient mice within six months of administration of a known genotoxic carcinogen (urethane).

Aventis' response: Aventis strongly believes that the use of carbaryl products presents no imminent carcinogenic risk to users based on the following points:

  Current data support a hypothesis that high doses of carbaryl in life time studies produce tumors via a non genotoxic mechanism, possibly related to altered metabolism at these high doses.

  At doses less than the MTD, there was an increased incidence of tumors only in 1 site of 1 sex of 1 species.

  The increased incidence of vascular tumors in the male mice after two years of administration is of questionable biological significance.

  In the p53 knockout mouse model, which was demonstrated, to be sensitive to the induction of vascular tumors by a genotoxic reference compounds, carbaryl was found to be negative.

  The weight of the evidence indicates that carbaryl shows no potential for genotoxicity   Epidemiological data on carbaryl production workers show no increase in tumor incidence.

As background, in the two year bioassay conducted in the CD1 mouse, a statistically significantly higher incidence of vascular tumors was noted in males at 1,000 and 8,000 ppm. In females, no statistically significant change in the incidence of vascular tumors was observed. The overall incidence of vascular tumors was 2, 6, 10 and 10 in males and 3, 3, 4 and 9 in females at 0, 100, 1,000 and 8,000 ppm respectively.

In order to address the biological significance of the vascular tumors, the p53 knockout mouse model was used as potential tool to study chemical carcinogenesis (Donehower, 1996). The p53 mouse is a genetically manipulated mouse in which one allele of the p53 tumor suppresser gene has been inactivated. One of the assumptions with the knockout model is that a mutation at the intact p53 allele is necessary for the development of the carcinogenic process. In principle non genotoxic compounds, which induce tumors by other mechanisms should not induce tumors in this system. The p53 knockout mouse model was validated by testing two compounds: urethane, a genotoxic compound known to produce vascular tumors in standard carcinogenicity bioassays, and d limonene, 17 which is neither genotoxic nor carcinogenic in mice but which is known to be carcinogenic in the male rat by a well described non genotoxic mechanism. In the validation study, the p53 model proved to be very efficient for the induction of vascular tumors by genotoxic compounds (Bigot, 1999; Carmichael et al. 1999). Therefore, this model will produce an unambiguous response to specifically identify genotoxic compounds.

Therefore, carbaryl was tested in the p53 mouse. The objectives of the studies were to evaluate if carbaryl would induce vascular tumors in this model and to set a NOEL in this sensitive and specific model. Additionally, this model provides evidence that the tumors observed in the standard carcinogenicity bioassays resulted from an indirect geneotoxic effect Carbaryl was administered continuously via the diet to groups of 20 male heterozygous p53 knockout mice at concentrations of 0, 10, 30 100, 300, 1,000 and 4,000 ppm for at least 180 days. At the end of the study, all animals were necropsied, selected organs weighed and a range of tissues were taken, fixed and examined microscopically. Carbaryl did not induce mortalities or clinical signs related to the treatment. Only a slight decrease in food consumption during the first eight weeks was observed at 4,000 ppm. This observation was correlated with a lower body weight evolution in comparison with the control animals.

No tumors were found in the 4,000 ppm group. In the other treated groups, a few sporadic tumors were found, but they were clearly unrelated to treatment and representative of the spontaneous tumor types present in mice of this age and strain. In particular, it should be noted that no tumors were found in the liver, kidney or vascular system, which were seen in the original mouse oncogenicity study with carbaryl. The only treatment related non proliferative change observed was the presence of globular deposits in the umbrella cell layer of the urinary bladder at 100 ppm or more.

In conclusion, the data from the p53 studies, the following conclusion can be made:

1). The p53 model was validated with urethane one of the few compound known to induce specifically vascular tumors. 2). Carbaryl was negative, and also did not accelerate the formation of any other tumor types. 3). There is a clear NOEL at 4000 ppm in the p53 mouse study for carcinogenicity. 4). Carbaryl is not a genotoxic carcinogen.

Thus the weight of the evidence indicates that carbaryl is not a genotoxic agent in humans. In addition, epidemiological data on carbaryl production workers show no increase in tumor incidence. The two epidemiology studies of Aventis CropScience (formerly Rhône Poulenc) factory workers representing a sub 18 population of the general public with the highest exposure (i. e., exposure on a daily basis over many years). Thus, the data from these studies represent a potential "worst case" for chronic carbaryl exposure to humans. The results from these studies show that the overall mortality experience of the cohort is significantly less than expected when compared to both United States and West Virginia male death rates. In general, these studies support conclusion that there were no excess cases of cancer in this working population.

Page: 18 Paragraph: 1 Lines: 1 8 EPA comment: Carbaryl was not mutagenic in the Salmonella typhimurium assay or genotoxic in the Unscheduled DNA Synthesis assay. In a chromosomal aberration test using Chinese Hamster Ovary (CHO) cells, carbaryl was clastogenic in the presence of S9 activation. The CPRC (1993 meeting) required an in vivo cytogenetics study in rodents to provide insight into the structural and/ or numerical aberrations in the study. The mouse micronucleus study submitted to satisfy this requirement was deemed unacceptable. HED concluded that, based on a Weight of the Evidence assessment, the database does not support that carbaryl acts as a DNA reactive mutagen. However, this alone is not sufficient to demonstrate a mode of action for establishing a threshold cancer risk assessment.

Aventis' response: The Agency has previously granted a wavier for the in vivo cytogenicity/ micronucleus. Furthermore, Aventis has fulfilled the data requirement for the in vivo mouse micronucleus study. Aventis believes that repeating the in vivo mouse micronucleus study is not appropriate based the fact that the top dose in the currently submitted mouse micronucleus was 200 mg/ kg/ day and was similar to the mid dose of 250 mg/ kg/ day tested in an acute gavage study in mice. At the 250 mg/ kg/ day dose level tested in the acute study plasma, RBC, and brain cholinesterase inhibition was seen. The percent cholinesterase inhibition observed was 45.7, 45.7, and 57.8, respectively. At the highest dose tested (500 mg/ kg) in the acute study, percent cholinesterase inhibition for plasma, RBC, and brain were 59.8, 57.1, and 66.6, respectively. Additionally, the clinical signs observed at both the 250 and 500 mg/ kg were very similar in both findings and incidences. Repeating the mouse micronucleus study at a slightly higher dose level would not result in an increase in significant clinical signs. Therefore, the base results of the study concerning clastogenic or aneugenic effects would not change. Carbaryl is not mutagenic for these endpoints.

Page: 18 Paragraph: 6 Lines: 1 8 EPA comment: The FQPA Safety Committee concluded at meetings on November 29, 1999 and April 16, 2001, that the 10x safety factor should be retained because: 1) the toxicology data base is incomplete; there is a data gap for the multi generation reproduction study in rats; 2) an assessment of susceptibility following pre/ post 19 natal exposure to carbaryl could not be made due to the data gap for the reproduction study; 3) there is concern for the results of the developmental neurotoxicity study (uncertainty about NOAEL/ LOAEL for brain morphometric alterations). The Committee concluded the 10x safety factor should be applied to all population subgroups when assessing acute and chronic dietary exposures and residential exposures of all durations.

Aventis' response: As stated above, Aventis has submitted to EPA a revised DNT Study and a new 2 Generation Reproduction Study which will have a direct impact on the FQPA Safety Factor. Aventis firmly believes that with the submission of these two studies, the data gap for the 2 generation reproduction study will be fulfilled and clarification of the DNT NOEL issue will be provided. Thus the Agency has the required data to reduce the FQPA Safety Factor from 10X to 1X. 20 Part I  Toxicology Data Base SUPPORTING DISCUSSIONS Supplemental Developmental Neurotoxicity Study Findings The document submitted to EPA describes the supplemental histomorphometric evaluation performed on the cerebellum of rat pups and adults from the carbaryl developmental neurotoxicity study (Robinson and Broxup 2001). This additional work was conducted in response to the EPA review of the study final report. In that review, EPA indicated that the bilateral decrease in the length of the cerebellum accompanied by a non statistically significant 5% decrease in cerebellar weights in the day 11 females and the bilateral increase in the width of the cerebellum in the day 70 female animals at the highest tested dose (10 mg/ kg/ day) may possibly be treatment related. Further, some forebrain measurements may have also been affected. In order to clarify the treatment relationship of these findings, the Agency recommended that additional morphometric measurements be performed to support the NOEL and that the thickness of the cellular layers in the cerebellum be more fully described.

The submitted report addresses the EPA comments by presenting additional evaluations of the high dose animals, only. The evaluations clearly demonstrate that there are no treatment related morphometric findings in the cerebellum of male and female pups and adults. These findings are in agreement with the results from the high dose group animals in the study final report that found no treatment related changes in: 1) Brain weights in male and female pups; 2) Cerebellar weights in male and female pups; 3) Terminal body weights in male and female pups; 4) Brain weights in male and female adults; 5) Terminal body weights in male and female adults; 6) FOB measurements and motor activity in male and female pups; 7) Motor activity, auditory startle response, passive avoidance, and water maze measurements in male and female adults.

The evaluations clearly demonstrate there are no treatment related morphometric alterations of the cerebellum in male and female pups or adults treated with carbaryl at a dose of 10 mg/ kg/ day, from Day 6 of gestation to Day 10 post partum, inclusively. In addition, in the forebrain no measurable bilateral differences are detected between control and carbaryl exposed pups and adults.

In conclusion, carbaryl did not induce any morphologic or morphometric changes in either the cerebellum or the forebrain in animals receiving a high dose of 10 mg/ kg/ day. As described, the new morphometric results revealed no changes at the high dose, are in agreement with the lack of treatment related effects on terminal body, brain, and cerebellar weights, as well as behavioral and motor activity tests in male and female pups and adults. 21 2 Generation Reproduction Study Findings A 2 Generation reproduction study with carbaryl technical was completed at Research Triangle Institute located in North Carolina, USA, in order to provide information on the influence of carbaryl technical on the reproductive performance in rats (Tyl et al. 2001). The purpose of this study was to evaluate the potential of carbaryl, administered in the feed to CD rats, to produce alterations in parental fertility, maternal pregnancy and lactation, and growth and development of the offspring for two generations, one litter per generation. This study was performed in compliance with U. S. EPA FIFRA GLP Standards (U. S. EPA, 1989), the U. S. EPA OPPTS Testing Guidelines (U. S. EPA, 1998), and the OECD testing guidelines for a two generation reproductive toxicity study (OECD, 1983).

Male and female CD® (Sprague Dawley) rats (the FO generation) were administered carbaryl (1 naphthyl methylcarbamate; CAS No. 63 25 2) in the feed at 0, 75, 300, and 1500 ppm, available ad libitum, 30 animals/ sex/ dose, for ten weeks. Body weights and feed consumption were recorded weekly, and clinical signs were recorded at least once daily. Vaginal cytology was evaluated for the last three weeks of the prebreed period. Animals were then randomly mated within treatment groups for a two week mating period to produce the Fl generation, with exposure continuing. FO males were necropsied after the delivery period, with histological evaluation of reproductive and other organs and andrological assessments (reproductive organ weights, epididymal sperm number, motility and morphology, testicular homogenization resistant spermatid head counts, daily sperm production, and efficiency of daily sperm production). Fl litters were culled to ten pups on postnatal day (pnd) 4 and weaned on pnd 21. At weaning, up to three weanlings/ sex/ litter were necropsied, and 30/ sex/ dose were selected as Fl parents of the F2 generation. FO females were then necropsied with organ weights, stage of estrus at necropsy, enumeration of ovarian primordial follicles, and histopathology of reproductive and other selected organs. Selected Fl weanlings, 30/ sex/ dose, were administered carbaryl in the diet for a ten week prebreed exposure period, with acquisition of vaginal patency in females and preputial separation in males assessed, and vaginal cytology for estrous cyclicity in Fl selected females evaluated during the last three weeks of the prebreed exposure period. They were mated for a two week period, as described above. At weaning of F2 litters, up to three weanlings/ sex/ litter were necropsied. Fl males were necropsied after the delivery period, with histopathology and andrological assessments (as described above). At weaning of the F2 litters, parental Fl females were then necropsied with histopathology, as described above, and F2 weanlings, up to three/ sex/ litter, were necropsied.

Dietary exposure to carbaryl for two generations, one litter per generation, at 0, 75, 300, and 1500 ppm, resulted in: decreased body weights and decreased weight gains in P0 and P1 parental males and females, accompanied by decreased feed consumption at 1500 ppm, and slightly reduced body weights and feed consumption at 300 ppm; Fl and P2 offspring toxicity (reduced body weights during lactation beginning on post natal day (pnd) 4 through lactation and continuing in selected P1 offspring through acquisition of puberty) at 1500 ppm; increases in P1 pup mortality at 1500 ppm and in P2 pup mortality 22 at 300 ppm and 1500 ppm during lactation, especially early (pnd 0 4), accompanied by reduced maternal body weights in FO and P1 dams at 1500 ppm and 300 ppm, and delayed vaginal opening and preputial separation in selected Fl offspring at 1500 ppm considered an indirect effect related to body weight decreases.

In conclusion, the NOELs for carbaryl administered in the diet, in CD® (SD) rats under the conditions of this study, were: ° parental systemic toxicity: 75 ppm ° parental reproductive toxicity: 1500 ppm ° offspring toxicity: 75 ppm EPIDEMIOLOGIC DATA  Epidemiological data on carbaryl: standardized mortality ratio analysis of employees exposed to carbaryl at the Rhône Poulenc Institute, West Virginia plant.

The National Institute of Occupational Safety and Health (NIOSH) and the Union Carbide Corporation (UCC) on chemical production plants in the Kanawha Valley (KV) of West Virginia originally initiated an epidemiological study. One of the plants included in this extensive epidemiology study was the facility at which carbaryl is produced in Institute, West Virginia. The plant was acquired by Rhône Poulenc (now Aventis CropScience) from UCC in December 1986.

The study (Pastides 1993) reported here investigated the total and cause specific mortality experience of employees exposed to carbaryl at the production plant. No additional information other than what was available in the original database was collected about the health or mortality experience of individuals employed at this plant for this study. The central results of this report were presented in terms of Standardized Mortality Ratios (SMR's) and 95% confidence intervals (95% CI's).

Carbaryl technical is manufactured, packaged, and shipped from the Aventis CropScience plant in Institute, West Virginia. Besides carbaryl, the plant also produces other agricultural products. In the past, numerous other chemical compounds were produced there, including butanol, styrene, acetaldehyde, toluene, fluorocarbons and others.

Carbaryl is produced in crystalline form, as well as in an oil based solution (41% carbaryl). Final processing includes crystallizing, drying, bin storage, and packing. Exposure to carbaryl would occur among three basic categories of employees: those in the manufacturing unit, those in maintenance, and those in packaging and distribution.

For employees of the carbaryl unit, UCC tracked through 1988 the vital status, and cause of death information, of all individuals who were first hired between the start up of the carbaryl unit in 1960 through 1978. Employees hired after 1978 were not part of the NIOSH/ UCC KV study. 23 Using the KV database, UCC conducted SMR analyses of the employees from the entire Institute plant in the past. However, no separate examination of data from employees specifically exposed to carbaryl was made. In the overall Institute study, no excess risk in total mortality, total cancer mortality, or site specific cancer mortality, was observed.

In the carbaryl specific study, a total of 522 employees were identified within the UCC database as belonging to one of the three carbaryl exposure groups; (158 Carbaryl Production, 229 Packing and Distribution, 327 Maintenance)

Because of some overlap between the groups and because some individuals did not meet the NIOSH/ UCC cohort entry criteria, the final number of employees available for the SMR analysis was 488. These 488 employees contributed 7,531.5 person years to the mortality analysis. This number represents the combined number of years in which these employees were followed through 1988.

As of the end of 1988, twenty five deaths were identified from this cohort of employees. Elevated SMR's, reflecting an observed number of deaths greater than the number expected were seen for cancer of the pancreas, cancer unspecified, and cancer of the brain and other parts of the nervous system. In the former two categories, the excess was slight and based on only a single death; furthermore the wide confidence intervals suggest a relatively imprecise SMR estimate and one that is well within the range of chance variation. In the case of brain and nervous system cancer, the higher SMR suggested a possibility of some association with work in the carbaryl unit, yet the very wide confidence interval indicates that the SMR estimate has low precision. In other words, the estimate is unstable, is within the range of chance variation, and reflects the small sample size on which it is based. Furthermore, review of the death certificates of these two individuals revealed that these tumors were of different histologic origin; one was reported as an astrocytoma, the other as a glioblastoma multiforme. This information reduces the plausibility that both malignancies were caused by the same exposure.

The next phase of the carbaryl plant worker epidemiology study has been completed (Pastides and Zorn, 1997), and the results are based on vital status of employees through 1994. The new cohort consisted of 817 employees (488 from the previous analysis and 329 who were hired after 1978). Taking into account restriction criteria, as described in the report, the restricted cohort that reflects the number of employees who worked across departments is 599. As previously shown, the overall mortality experience of the cohort is significantly less than expected when compared to both United States and West Virginia male death rates. In general, the follow up study supported the results from the initial study that there were no excess cases of cancer in this working population. 24 Carcinogenicity Issue – Historical Perspective and as presented to JMPR and submitted to EPA in 2000 A. Combined Oncogenicity/ Chronic Toxicity Studies 1) Carbaryl produced tumors primarily at the highest dose tested.

The dietary concentrations in the rat study were 0, 250, 1500, and 7500 ppm (approximately 13, 75, and 375 mg/ kg b. w.); for the mouse study the concentrations of technical carbaryl were 0, 100, 1000, and 8000 ppm (approximately 12, 143, and 1143 mg/ kg). The highest doses were chosen to satisfy the U. S. EPA requirement for an MTD, while the lower doses were selected for determining the NOEL and to produce moderate toxicity in tissues and on cholinesterase. Considering an approximate acute oral LD 50 in rats and mice of 250 mg/ kg, these doses would therefore be equivalent to 0.06, 0.6 and 4.6 times the acute oral LD 50 for mice and 0.05, 0.3 and 1.5 times the acute oral LD 50 for rats. (The high doses for the mouse and rat, respectively, also would be equivalent on a body weight basis to a 70 kg person consuming approximately 80 grams and 26 grams of technical carbaryl per day for a lifetime.)

These MTD levels caused a significant reduction in body weight and body weight gain in both species, especially early in the study. Several other parameters, such as cholinesterase, were also significantly affected throughout the studies at the top doses. The U. S. EPA in their review of the studies agreed that the highest doses in the mouse and rat study exceeded the MTD. As a result, these MTD levels were deemed inappropriate for chronic testing.

Therefore, the only relevant findings for establishing a carcinogenic classification are the vascular system tumors in male mice.

2) The data supporting the oncogenic potential of carbaryl is equivocal since tumors occurred only at one site of one sex of one species when irrelevant data at doses exceeding the MTD are excluded from consideration.

Rat Study In the rat carcinogenicity study, carbaryl produced tumors in both sexes (thyroid and bladder in males; liver and bladder in females) but only at the MTD (375 mg/ kg). At the low and intermediate doses (13 and 75 mg/ kg, respectively) there was no indication of an increased incidence of tumors at any of the sites for which increases occurred at the top dose. Thus, at levels less than the MTD, carbaryl has not produced tumors in rats, whether considering the current study or a previous study in which another rat strain was tested. 25 Mouse Study In the mouse carcinogenicity study, carbaryl produced tumors (liver and vascular) in females only at the highest dose tested (1143 mg/ kg). At the low and intermediate doses (12 and 143 mg/ kg, respectively) there was no indication of an increased incidence of tumors at any of the sites for which increases occurred at the top dose. Thus, at doses less than the MTD, carbaryl did not produce tumors in female mice in the current study or in an older study.

In male mice, carbaryl produced tumors in the vascular system and kidney at the highest dose tested (1143 mg/ kg b. w.). At the low and intermediate doses (12 and 143 mg/ kg) there was no indication of an increased incidence in kidney tumors. At the low and intermediate doses there was an apparent increase in the incidence of vascular tumors as follows:

Dose Male Mouse Vascular Tumors (mg/ kg) Benign Malignant Total 0 122 12 1 6 7 143 1 9 10 1143 3 7 10 However, despite a nearly 10 fold increase in dose increments, the total tumors observed at the intermediate and high doses were the same. The number of malignant tumors actually was slightly lower at the high dose than at the intermediate dose. Thus, these results show there is no clear linear dose response relationship from the intermediate dose to the high dose, despite a nearly 10 fold difference in dose increment.

With regard to statistical significance, the performing laboratory indicated that statistical significance was just achieved at the p< 0.05 levels for the top dose, while the intermediate dose results were just above this level of statistical significance (this result was due to the actuarial type statistical analysis used for tumor incidence and onset). However, the U. S. EPA and U. K. authorities have performed separate statistical analyses and the tumor incidence at the intermediate dose also was found to fall within statistical significance. Based on the results from the original study report, a NOEL could be established based on the lowest dose tested at approximately 12 mg/ kg b. w. However, arguments are made in succeeding sections that 18 month historical control data from the performing laboratory are inadequate to determine if the incidence of tumors at any of these doses is biologically significant.

As previously stated, vascular tumors were produced in the female mice but only at the top dose and with a very similar incidence (N = 9) as observed in the males at the top dose. In most other aspects of the study, e. g., body weight effects, clinical signs, clinical 26 pathology, etc., the females reacted very similar to males. However, there was no indication of an increased incidence of vascular tumors in females at the low or intermediate doses as was observed in the male mice. Thus, these facts raise questions regarding the biological significance of the vascular tumors, which occurred in the male mice.

3) Adequate historical control data were not available from the laboratory conducting the chronic toxicity and oncogenicity studies.

Historical data from the laboratory at which the mouse oncogenicity study was conducted was only available for studies conducted up to 18 months. Aventis CropScience was not certain if these data accurately reflected the incidence of vascular tumors in 24 month CD 1 mice. Additional information was obtained from other sources and summarized (Klonne, 1995) to compare historical control data from several sources and at several study intervals to that of the data for the carbaryl study. The following key observations were made:

  An increase in the spontaneous vascular tumor incidence appears to occur from 18 to 24 months of age in mice.

  An increase in the spontaneous vascular tumor incidence over the last 10 years may be occurring in CD 1 mice.

  The carbaryl study (a 2 year study) should be compared to historical control data from 2 year old mice generated during the last 10 years.

In general, considering the most relevant historical control data outside of the performing laboratory, the incidences of vascular tumors in major organs (spleen/ liver) in male mice at the low and middle doses fall within the historical control ranges.

4) The lack of significant histopathological findings at the one year interim sacrifice of both the mouse and rat studies did not correlate with the detection of tumors in certain tissues at the end of the study.

To further investigate the mechanism by which carbaryl induced multiple tumors in the rat and the mouse after two years of exposure, a decision was made to re evaluate the histological slides of target organs from the interim sacrifice after one year of treatment. The purpose of this work was to identify if subtle changes present at one year could explain the appearance of tumors seen at two years.

Histopathological examinations were conducted on the target organs (liver, kidney, thyroid gland, urinary bladder) from the control and high dose groups in rats and/ or mice. The review was conducted independently by two of Aventis CropScience's pathologists (Debruyne and Irisarri, 1996).

In the rat, at the end of a 52 week exposure period to carbaryl technical by the dietary 27 route, the re evaluation of the histological slides revealed the presence of microscopic changes not previously reported in the bladder (transitional epithelial hyperplasia in both male and females), kidney (pelvic urothelial hyperplasia in males), and thyroid (thyroid follicular hypertrophy in males) and liver (hepatocellular hypertrophy in males and females).

In the mouse, no microscopic changes were detected at the end of the 52 week exposure period.

These new findings prompted the Aventis CropScience to conduct further studies to confirm cell proliferation in the various tissues (associated with positive tumor formation) and to re examine the histological slides from the chronic toxicity and oncogenicity studies.

5) Oncogenicity and chronic toxicity slide review Aventis CropScience then commissioned independent pathologists to re examine the histological slides at the 1 year and 2 year sacrifices from the chronic toxicity and oncogenicity studies to determine what other (if any) discrepancies exist outside of those determined by the Aventis CropScience's internal review. This peer review study was conducted according to US. EPA Peer Review policy guidelines. The results of this review showed no differences from the original study pathologists review.

B. Carcinogenic Mechanism 1) Subsequent to the two year studies, Aventis CropScience proactively performed in vivo genotoxicity studies.

In response to the results of the mouse oncogenicity study, Aventis CropScience proactively conducted an in vivo DNA adduct study in mice at a concentration similar to the top dose used in the two year carcinogenicity study (i. e., 8000 ppm) to determine if carbaryl caused any genotoxic effects (Sagelsdorff, P. 1994). Results indicated that carbaryl did not interact with the DNA in mice, even at the excessive dose used in the study. Additionally, an in vivo rat bone marrow chromosomal aberration study was conducted and showed that carbaryl did not produce chromosomal aberrations at doses up to approximately 50% of the acute oral LD 50 (McEnaney, 1993). Although there was no indication of genotoxic effects in the rat chromosomal aberration and mouse DNA adduct studies, Aventis CropScience recently conducted an in vivo micronucleus study in mice to determine if carbaryl produced aneuploidy in this species. Results from the mouse micronucleus assay again showed no genotoxic effects (Marshall, 1996).

Thus, results from these in vivo studies indicate that the mechanism of action of carbaryl in the production of tumors in the two year oncogenicity studies does not occur via a direct genotoxic effect. 28 2) The weight of the evidence approach indicates that carbaryl shows little potential as a genotoxin.

There have been nearly 50 literature and Aventis CropScience reports on the genotoxicity of carbaryl. The number of test systems and endpoints is extensive. In neither bacterial nor mammalian cell cultures has carbaryl demonstrated any significant mutagenic potential. In various in vitro DNA damage and repair assays there is no convincing evidence to suggest that carbaryl produces DNA damage. While carbaryl has shown some clastogenic potential in vitro, these changes occur at or near cytotoxic levels. In addition, studies performed in vivo, the mouse DNA adduct and rat chromosomal aberration (previously discussed), a mouse dominant lethal study, and an evaluation for mouse micronucleated polychromatic erythrocytes all have been negative.

The absence of tumor induction in a 6 month carcinogenicity study conducted in the p53 knockout mouse demonstrated that the tumors observed in the standard two year bioassays in rats and mice are not linked to an indirect genotoxic mechanism.

3) It is possible that altered metabolism from unrealistically high doses of carbaryl plays a significant role in the formation of these tumors.

The results from the metabolism study indicated that the carbaryl was almost completely absorbed and metabolized (approximately 90%) and that there was essentially no difference in the metabolism between the sexes or in the low versus the high dose. Likewise, there was no difference in the metabolism between the single versus multiple doses.

The data also indicated that the low dose was almost completely eliminated in 12 hours and the high dose was almost completely eliminated in 24 hours. Two metabolites, 5,6 dihydro 5, 6 dihydroxy carbaryl and 3,4 dihydro 3, 4 dihydroxy carbaryl were identified to be approximately 8% and 1%, respectively, of the total dose and were found to be primarily conjugated to glucuronide. These metabolites are very likely result from the metabolism of epoxide intermediates. Other metabolites, which were likely formed from the epoxide intermediates, were identified as 5 hydroxycarbaryl (13%) and 4 hydroxycarbaryl (6%) and conjugated carbaryl (3%).

Epoxide intermediates have been proposed to be the proximate carcinogen for several classes of carcinogens. Depending on such factors as the stability of the epoxide intermediate, the ability of the cell to detoxify the epoxide (related to such factors as the available glutathione stores, epoxide hydrase activity, etc.), the excretion pattern of the compound, etc., these reactive intermediates may be routinely handled by the body just like other endogenous epoxides or could be available to react with cellular components. Thus, it is possible that excessively high doses of carbaryl could alter the normal metabolism, distribution, and/ or excretion pattern in many different ways, e. g., saturate the normal metabolic pathways with a shift of carbaryl metabolism through the epoxide 29 intermediates, deplete the available glutathione stores available for conjugation, increase the half life of the epoxide intermediates, increase tissue concentrations of carbaryl and its metabolites due to diminished ability for excretion, etc. Additionally, saturation of many enzyme systems with large carbaryl substrate concentrations could allow accumulation of endogenous chemicals and by products of normal metabolism that would otherwise be detoxified and excreted.

4) Vascular tumors.

In the two year bioassay conducted in the CD1 mouse, a statistically significantly higher incidence of vascular tumors was noted in males at 1,000 and 8,000 ppm. In females, no statistically significant change in the incidence of vascular tumors was observed.

A search of the literature indicated there is very few chemical agents known to induce vascular tumors in humans, among them utherane and vinyl chloride were identified (Creech, J. L. Jr et Johnson, M. N. 1974). Angiosarcoma of liver in the manufacture of polyvinyl chloride. (J. Occup. Med. 16: 150 151; Marion, M. J., De Vivo, I., Smith, S., Luo, J. C. and Brandt Rauf, P. W. 1996). The molecular epidemiology of occupational carcinogenesis in vinyl chloride exposed workers (Int. Arch. Occup. Environ. Health, 68: 394 398) and the mechanism underlying the formation of vascular tumors is through the formation of etheno adducts, formed maybe by reactive oxygen species (Barbin, A. 2000. Etheno adduct forming chemicals: from mutagenicity testing to tumor mutation spectra. Mutation Res. 462: 55 69: Nair, J., Barbin, A., Velic, I. and Bartsch, H. 1998). Etheno DNA base adducts from endogenous reactive species (Mutation Res. 424: 59 69). All those compounds would have been found to induce vascular tumors in the p53 model. Thus, the study using the genetically modified heterozygous p53 knockout mouse was designed to address the potential role of an indirect genotoxic mechanism in the induction of vascular tumors in mice.

Carbaryl was administered continuously via the diet to groups of 20 male heterozygous p53 knockout mice at concentrations of 0, 10, 30 100, 300, 1,000 and 4,000 ppm for at least 180 days. No treatment related tumors were found even in the highest dose ppm group. In particular, it should be noted that no tumors were found in the liver, kidney or vascular system. Under the conditions of this study, the NOEL is 4,000 ppm (approximately 716 mg/ kg b. w./ day) for neoplastic changes.

C. Epidemiological/ Worker Exposure Information Epidemiological evaluations of carbaryl production workers, the population of exposed persons with the highest and most consistent carbaryl exposure, show no indication of effects on tumor incidence.

The two epidemiology studies of Aventis CropScience factory workers representing a sub population of the general public with the highest exposure (i. e., exposure on a daily basis over many years). Thus, the data from these studies represent a potential worstcase for chronic carbaryl exposure to humans. The results from these studies show that 30 the overall mortality experience of the cohort is significantly less than expected when compared to both United States and West Virginia male death rates. In general, these studies support conclusion that there were no excess cases of cancer in this working population.

SUMMARY Aventis CropScience strongly believes that the use of carbaryl products present no imminent carcinogenic risk to users based on the following points:

  Current data support a hypothesis that high doses of carbaryl in life time studies produce tumors via a non genotoxic mechanism, possibly related to altered metabolism at these high doses   At doses less than the MTD, there was an increased incidence of tumors only in 1 site of 1 sex of 1 species.

  The increased incidence of vascular tumors in the male mice after two years of administration is of questionable biological significance   In the p53 knockout mouse model, which was demonstrated, to be sensitive to the induction of vascular tumors by a genotoxic reference compound, carbaryl was found to be negative   The weight of the evidence indicates that carbaryl shows little potential for genotoxicity   Epidemiological data on carbaryl production workers show no increase in tumor incidence 31 REFERENCES 1. Bigot, D. 1999. Validation on Transgenic Mice – p53 Knockout Mice – to Predict Rodent Carcinogenicity. Non Guideline Study. Rhône Poulenc Agro. Study No. SA 97040. November 10, 1999. 460pp. MRID 45281802. 2. Carmichael NGC, Debruyne ELM and Bigot Lasserre D. 2000 The p53 heterozygous knockout mouse as a model for chemical carcinogenesis in vascular tissue. Envi. Health Perspective. 108: 61 65. 3. Debruyne, E. and Irisarrri, E. (1996). Carbaryl technical  chronic toxicity study in the rat (HWA Study No. 656 139) and the mouse (HWA Study No. 656 138): evaluation of histological slides. Rhône Poulenc agrochimie report No. R& D/ CRSA/ TOX HPA 4. Unpublished report. MRID 45365503. 4. Donehower LA: The p53 deficient mouse: a model for basic and applied cancer studies. Semin. Cancer Biol., 7, 269 278 (1996). 5. Klonne, D. R. 1995. Carbaryl mouse historical control data  position paper, November 1995. Rhône Poulenc. 74 pp. MRID 45365501. 6. Marshall, R. 1996. Carbaryl: induction of micronuclei in the bone marrow of treated mice. CH Study No. 198/ 89 1052. Corning Hazelton. Unpublished report. MRID 44069301. 7. McEnaney, S. 1993. Study to evaluate the chromosome damaging potential of carbaryl technical by its effects on the bone marrow cells of treated rats. Hazelton Microtest. Hazleton U. K. Study No. 198/ 64. Unpublished report. MRID 43039301. 8. Pastides, H. 1993. Standardized mortality ratio analysis of employees exposed to carbaryl at the Rhône Poulenc Institute, West Virginia Plant. Unpublished report. MRID 42901501. 9. Pastides, H., and M. Zorn. 1997. An evaluation of the mortality experience of carbaryl unit employees at the Rhône Poulenc Institute, West Virginia Plant. Unpublished report. MRID 44349901 10. Sagelsdorff, P. 1994. Investigation of the potential of protein and DNA binding of carbaryl. CIBA GEIGY Limited Toxicology Services/ Cell biology. Study No. CB93/ 52, unpublished report. MRID 43282201. 11. Robinson, K. and Broxup, B. 2001 A Developmental Neurotoxicity Study of Orally Administered Carbaryl, Technical Grade, in the Rat. Lab. I. D. Number 97391. Performed by ClinTrials BioResearch Ltd. 34 pages. Submitted to EPA in July 2001. 12. Tyl, R. W., Myers, C. B., and Marr, M. C. 2001 Two Generation Reproductive Toxicity Evaluation of Carbaryl (RPA007744) Administered in the Feed to CD (Sprague Dawley) Rats. RTI I. D. Number 65C 07407 400. Performed by Research Triangle Institute. 906 pages. Submitted to EPA in June 2001. 32 Part II  Dietary and Water Exposure/ Risk Assessment Line by Line Review of the Dietary and Water Exposure Assessment of the Human Health Risk Assessment Document for Carbaryl (June 19, 2001)

1.0 Executive Summary Page: 3 Paragraph: 5 Line: 3 EPA Comment: No acceptable two year reproduction study is available.

Aventis Response: A study has been completed and submitted. The data gap to remove the 10X FQPA safety factor has been filled.

Page: 6 Paragraph: 2 Line: 1 EPA Comment: Monitoring data for carbaryl residues in ground and surface water are available but they are of limited utility in developing estimated environmental concentrations for the aggregate dietary (food and water) risk assessment.

Aventis Response: Monitoring data submitted by Aventis is directly applicable to drinking water residue use in the aggregate (food and water) assessment. Worst case community water supply systems, targeted for maximum carbaryl use, were monitored for three years on a weekly basis during peak carbaryl use times.

4.0 Exposure Assessment and Characterization 4.2.1 Residue Profile Page: 25 Paragraph: 2 Line: 1 EPA Comment: HED conducts dietary risk assessments using the DEEM™ which incorporated consumption data generated in USDA's Continuing Surveys of Food Intakes by Individuals (CSFII), 1989 1992.

Aventis Response: The CSFII data for the years 1994 1996 have been available for several years now. These data should be used as it reflects the most recent eating patterns and habits of the U. S. population that is currently available. 33 Page: 26 Paragraph: 3 Lines: 1 5 EPA Comment: Most of the processing factors were obtained from processing studies submitted by the registrant and compiled in a memo entitled "Carbaryl Anticipated Residues for Carcinogenic Dietary Risk Assessment." S. Hummel, 12/ 3/ 93.

Aventis Response: The studies in this memo are older processing studies submitted in the 1980's or even earlier. New residue processing studies were done in the early to midnineties in conjunction with the Residue Chemistry DCI. These studies are listed with MRID numbers in EPA's Product and Residue Chemistry documents. The factors are listed in the `Discussion Section' below. These factors should be used in the dietary risk assessment as they represent newer, GLP data.

Page: 27 Paragraph: 1 Line: 5 EPA Comment: As discussed in section 3.2, the 10X safety factor is retained for carbaryl.

Aventis Response: The data gaps and concerns for the FQPA safety factor have been addressed by Aventis with the submission of the 2 generation rat reproduction study and the additional data generated for the developmental neurotoxicity study. Based upon the outcome of the studies provided, the 10X safety factor is no longer justified and should be removed. There are no populations of concern in this assessment when the corrected RfD is used in the risk calculation (excluding poultry and using the CMBS data).

4.2.2 Acute Dietary Exposure Assessment Page: 29 Table 6: EPA Comment: The top heading of the table is labeled "Acute All Commodities at the 99.9 th percentile of exposure (Market Basket Survey Data Used in Place of PDP/ FDA data.)

Aventis Response: This top table heading should be labeled: "Acute All Commodities at the 99.9 th Percentile of Exposure (Market Basket Survey Data Not Included).

4.2.5 Characterization/ Uncertainties of the Risk Estimates 34 Page: 31 Paragraph: 1 Line: 1 EPA Comment: Cooking factors were available for potatoes only.

Aventis Response: A survey of the literature data revealed numerous cooking and washing studies for carbaryl. See `Discussion Section' for a list of these studies and a table of processing/ washing/ cooking factors that can be derived for carbaryl from these literature studies.

4.3 Water Exposure/ Risk Pathway Page: 31 Paragraph: 5 Line: 4 EPA comment: Some non targeted monitoring data are available but they are of limited utility in developing estimated environmental concentrations (EECs) for ecological and human health risk assessment.

Aventis' response: Aventis believes that the highest estimated EECs of relevance for ecological risk assessment are not relevant for estimating human health risks due to the lack of proximity of drinking water sources to likely areas of highest ecological risk. The drinking water monitoring program conducted by the registrant provides a real world assessment of the potential for human exposure to carbaryl in drinking water derived from surface water. Drinking water concentrations derived from PRZM/ EXAMS greatly overestimate the potential exposure to carbaryl in drinking water, generally by several orders of magnitude.

Monitoring Data Page: 32 Paragraph: 4 Line: 2 (and elsewhere) EPA comment: USGS NAQWA (sic) program Aventis' response: The correct abbreviation for the USGS water monitoring program is NAWQA.

Page: 32 Paragraph: 5 Line: 2 EPA comment: Because of limitation in the analytical methods used there is some question as to the accuracy of carbaryl analysis. 35 Aventis' response: This generalized statement needs to be qualified or deleted. Whereas the authors of reports written as part of the NAWQA program have been clear about the potential limitations of the quantitative nature of the carbaryl data in the database, they have also been clear about the validity of the qualitative nature of the data. The use of the multi residue method in the NAWQA program does have some limitations as a result of the large numbers of diverse pesticides and degradation products that they are monitoring. However, the QC/ QA data generated as part of the NAWQA program (described in the discussion section on surface water at the end of the EFED response) demonstrates the validity of the detections of carbaryl in the studies. The monitoring study conducted by the registrant, and reported in this section, does not have the same potential limitations in the analytical method since the method is looking specifically for only carbaryl. Therefore, the analytical method used by the registrant does not raise questions about the accuracy of the carbaryl analysis.

Page: 32 Paragraph: 5 Line: 3 EPA comment: Poor analytical methods probably have resulted in lower detection rates and lower concentrations than actually present.

Aventis' response: This generalized statement should be deleted for reasons provided above and in the discussion section of the EFED response.

Page: 33 Paragraph: 2 Line: 6 EPA comment: The data do not give a good indication of the effectiveness of treatment because samples existing and entering the treatment plant were different. In several cases, finished water had higher concentrations than raw water and finished water had detectable carbaryl when the raw did not.

Aventis' response: Obtaining matched samples is not possible because of varying residence time through the treatment system, as well as mixing that occurs. The minimal amount of carbaryl residues found also made observations regarding treatment less definitive. However, an examination of the data does indicate that carbaryl concentrations were generally lower in finished water than in raw water samples collected at the same time. These data do include several instances where carbaryl was detected over a few weeks in the raw water so the effect of sample time is less important. The statement regarding several cases of finished water having higher concentrations than raw water is misleading and certainly does not consider the analytical uncertainty for concentrations below the level of quantification and near the level of detection. There were only two cases when finished water was greater than raw water when the concentrations in finished water were greater than 0.01 ppb (only one third of the quantification limit). One 36 case was when the raw water was 0.009 ppb and the finished water was 0.011 ppb. These two analyses are essentially equivalent, especially considering that they are only about a third of the quantification limit. The other case was at the Deerfield community water system. This drinking water facility uses a small river without a reservoir as a source for a small Community Water System. Farms are located immediately upstream of the facility. The intake is also not continuous (shut down over weekends). Therefore, getting a matching sample is quite difficult, especially for a short duration spike as a result of spray drift, summer thunderstorm, or perhaps a spill that almost immediately enters the river as a runoff event. The rarity of this event is demonstrated by the absence of residues of this magnitude the next year (2000). Samples collected through this time of the year in 2001 also do not indicate a similar event. Although the data from this site cannot be used to determine the peak concentration, the data provide a distribution of residues through the three year period which will define up to the 99 th percentile concentration of the distribution.

The Deerfield, Michigan community water system is one of the systems in which the greatest variability of residues would be expected. Most of the other community water systems are located on larger rivers, lakes, or reservoirs.

Because the design of study called for analysis of finished water only when there were residues in the raw water, there was only one finished sample analyzed when the raw water contained no residues. This sample was collected at the Deerfield community water system at the sampling interval after the finding of 0.16 ppb in the Deerfield system. The residue level in this sample was 0.004 ppb. The difference between 0.004 ppb and non detect is insignificant, and if real can probably be attributed to water at much higher concentrations remaining in the system from the previous week.

Page: 33 Paragraph: 2 Line: 10 EPA comment: This illustrates that carbaryl contamination is transient, and that it is unlikely that any sampling would catch the actual peak concentration Aventis' response: The role of a peak concentration is in dietary exposure assessment is undergoing re examination within EPA. The current policy of EPA appears to define a certain percentile as an appropriate value for use in screening assessments, but the exact percentile to be used is being defined by EPA management. For more comprehensive assessments, a distribution of values is preferred.

The peak concentration in this study was measured at a community water system on a small river. The registrant agrees that the sampling schedule was not adequate to determine the true peak in such systems. Most of the other community water systems are located on larger rivers, lakes, or reservoirs. Therefore, the peak values are not likely to be an order of magnitude greater than 37 the amounts detected in this monitoring program.

Page: 33 Paragraph: 2 Line: 13 EPA comment: Non targeted monitoring, such as the NAWQA program has shown that much higher concentrations occur.

Aventis' response: The main reason why the drinking water monitoring study did not show residues as high as in the NAWQA program is the location of the sampling points. Drinking water supplies tend to be located on larger surface water bodies than NAWQA sampling points (or in other words, the intakes for community water systems tend to be downstream of NAWQA sampling points). This additional time allows for additional degradation and dilution to occur. Finding the highest concentration at the Deerfield, Michigan system is not surprising since this intake is on one of the smallest surface water bodies included in the monitoring study.

Page: 33 Paragraph: 2 Line: 14 EPA comment: This study, while useful, does not provide sufficient information to allow estimation of actual peak and mean concentrations that actually occur in all areas or the effect of treatment.

Aventis' response: Because most of the samples did not contain carbaryl residues, accurate estimates of the actual peak and mean concentrations can not be obtained. However, the distributions obtained from all sites can be used to define up to the 99 th percentile concentration. The average cannot be accurately determined; however, the timeweighted average is only slightly above the limit of detection (and certainly less than 0.01 ppb) at all 20 sites. The study provides information on concentrations of carbaryl in community water systems most likely to contain the highest concentrations of carbaryl. Residues of carbaryl in other areas would be expected to be lower. The study does not provide information on concentrations in smaller surface water bodies or in areas where surface water is not used for drinking water. Because drinking water concentrations are what is needed for FQPA dietary calculations, this information is suitable for use in dietary exposure assessments.

Page: 34 Table 8 EPA comment: Carbaryl EEC Values Aventis' response: Aventis has provided a more detailed response to this same table that is presented as Table 6 in the draft EFED chapter. An electronic copy of the EPA Memorandum on "Refined Estimated Environmental Concentrations for 38 Carbaryl" (DP Bar Code D267276, authored by E. Laurence Libelo, July 23, 2001, and sent to Anthony E. Britten and Virginia Dobozy) was provided to Aventis and contains the PRZM model inputs that were used to generate the EECs shown in this table. An abbreviated version of our response to the information from EFED is included below.

It would be useful to add another column to Table 8 to specify which method of application was used to generate the EECs. It would also be of benefit for the Agency to state which of the carbaryl labels were used to develop the "maximum" label application rate scenarios.

The model parameters listed in the Memorandum show that the "average" scenarios for citrus and apples were conducted using aerial applications. Few applications to these crops are made aerially. Therefore, the model results overestimate the contributions from spray drift since the "average" applications to these crops are made using ground airblast equipment with lower spray drift inputs.

The "maximum label rate" application scenario for apples that is allowed by the Sevin brand XLR PLUS label (E. P. A. Reg. No 264 333), the Sevin brand 80WSP and CHIPCO Sevin brand 80WSP labels (E. P. A. Reg. No 264 526) and the CHIPCO Sevin brand SL label (E. P. A. Reg. No 264 335) is 5 applications at 3 lb. ai/ A/ application made every 14 days. The scenario used in the model applies less than the maximum amount of product allowed by the labels. In addition, application timing was used in the modeling for the Index Reservoir scenario (applications made by air every 4 days) that would be a violation of the Aventis labels that restrict applications to a minimum of every 14 days.

The "average" scenario for sweet corn in Ohio should be 3 applications at 1.1 lb ai/ A/ application (as noted in the memo, "Average application rate from Quantitative Usage Analysis for Carbaryl, prepared July 21, 1998 by Frank Hernandez, OPP/ BEAD") and not the 2 applications at 3.4 lb ai/ A/ application as listed in the table. The PRZM input file shows the correct inputs of 3 applications at 1.1 lb ai/ A/ application. Likewise, the "average" scenario for sugar beets in Minnesota should be 1 application at 1.3 lb ai/ A/ application. The "Citrus" scenario would be more appropriately labeled Oranges. For the average scenario, the 3.4 lb. ai/ A/ application rate listed in Table 8 is for oranges which is the highest "average" application rate for any type of citrus. Therefore, this "average" scenario for oranges is at the high end for all citrus and overestimates the EECs for use in the other citrus crops.

4.3.1 DWLOCs for Acute Dietary Exposure. 39 Page: 35 Paragraph: 1 Line: 7 EPA Comment: Therefore, there is no allowable contribution for water to the risk cup.

Aventis Response: Based on a corrected acute reference dose for carbaryl (no 10X FQPA safety factor) and the exposure assessment that uses the Carbamate Market Basket Data, DWLOCs can be calculated. (see `Discussion Section' for calculations.)

4.3.2 DWLOCs for Chronic Dietary Exposure Page 36 Table 9 EPA Comment: DWLOC( chronic) calculations in Table.

Aventis Response: Based on a corrected chronic reference dose for carbaryl (no 10X FQPA safety factor) the DWLOCs should be calculated as shown in the `Discussion Section'. Based on the corrected values, there are no population subgroups of concern.

8.0 Data Needs/ Label Requirements Product Chemistry Data Gaps Page: 97 Paragraph: 2 Line 1 EPA Comment: Additional data are required depicting carbaryl residue in/ on cotton gin byproducts.

Aventis Response: Aventis is not supporting the cotton use and has removed this crop from the labels. Aventis CropScience requested cancellation of this use in a letter to Mr. George Tompkins, RD, on January 22, 1999. A Federal Register Notice dated April 14, 1999 announced receipt by the Agency of an application from RhonePoulenc Ag Company (now Aventis CropScience) to cancel the use of carbaryl products on cotton 40 Line by Line Review of the Supporting Document "Revised Dietary Exposure Analysis for the HED Revised Human Health Risk Assessment (Felicia A. Fort; April 26, 2001)"

Conclusions/ Summary Page: 2 Paragraph: 1 Line: 8 EPA comment: At the present time, information from the industry sponsored Carbamate Market Basket Survey has not been completely approved for use in dietary risk assessments.

Aventis Response: The CMBS protocols were presented to EPA for comment before the studies were started. These studies were specifically conducted to obtain more realistic residues for consumer's "at the plate" to be used in dietary assessments. As agreed with EPA before this study was started, the CMBS data should take precedence over others for use in dietary assessment (after their quality review has been completed).

Chronic Page: 2 Paragraph: 2 Line: 8 EPA comment: When poultry is not considered in the risk estimate, the dietary exposure is < 6% of the cPAD for all population subgroups.

Aventis Response: When a corrected cRfD is used (no FQPA 10X) and poultry is not included in the risk estimate, the dietary exposure is < 0.6% of the cRfD for all population subgroups.

Acute Page: 3 Continuation from Paragraph: 4 of Page 2 Line: 3 EPA Comment: Subsequent dietary analyses and all additional sensitivity analyses were conducted without poultry; the risk estimates were still of concern for all population subgroups with the all infants population subgroup consuming 260% of the aPAD when CMBS data were used.

Aventis Response: When a corrected aRfD is used (no FQPA 10X) , there are no concerns for all population subgroups. The all infants population subgroup consumes 26% of the aRfD when CMBS data are used. 41 Residue Data Page: 5; Paragraph: 2; Line: 4 EPA comment: FDA monitoring data were used for … cherries, raspberry, blueberry, raspberry, asparagus, … Aventis response: Second listing of "raspberry" can be deleted.

Page: 5; Paragraph: 2; Line: 9 EPA comment: Field trial data were used for the commodities, garden beets, turnips, mustards, dried beans, almonds, pecans, walnuts, field corn grain, rice, flax seed, okra, olive, peanuts, pistachio, and sunflower.

Aventis response: According to Table 6a, the following commodities should be added to this list: sugar beets and dried peas Page: 5; Paragraph: 2; Line: 11 EPA comment: For oysters, the tolerance of 2 ppm was used in the assessment.

Aventis response: According to Table 6a, the tolerance of 0.2 ppm was also used for Dill (fresh) in the assessment.

Processing Factors Page 6 Paragraph: 1 Table 2 EPA comment: Most of the carbaryl processing factors were obtained from processing studies submitted by the registrant and compiled in a memo entitled "Carbaryl Anticipated Residues for Carcinogenic Dietary Risk Assessment", S. Hummel, 12/ 3/ 93.

Aventis Response: As previously state, the studies in this memo were older processing studies submitted in the 1980's or even earlier. New residue processing studies were done in the early to mid nineties in conjunction with the Residue Chemistry DCI. These studies are listed with MRID numbers in EPA's Product and Residue Chemistry documents. The factors are listed in the Discussion section. These factors should be used in the dietary risk assessment as they represent newer, GLP data. 42 Consumption data Page: 7 Paragraph: 1 Line: 1 EPA Comment: HED conducts dietary risk assessments using the DEEM™ which incorporated consumption data generated in USDA's Continuing Surveys of Food Intakes by Individuals (CSFII), 1989 1992.

Aventis response: As previously stated the CSFII data for the years 1994 1996 have been available for several years now. These data should be used as it reflects the most recent eating patterns and habits of the U. S. population that is currently available.

Results Page: 7 Paragraph: 2 Line 2 EPA comment: Additional cooking and processing studies would allow further refinement.

Aventis response: A literature search resulted in many literature references to cooking, washing and peeling studies for carbaryl treated commodities. Average cooking, washing factors can be derived from these literature studies. See the `Discussion Section' for a list of the references and the average calculated factors.

Characterization/ Uncertainties of the Risk Estimates.

Page: 9 Paragraph: 2 Line: 1 EPA comment: Additional cooking factors could further reduce the risk estimates.

Aventis response: Numerous literature studies have been conducted on other commodities, see the `Discussion Section'.

Attachment 1: Anticipated Residues Summary and Residue Distribution Files Table 6a: Summary of Anticipated Residues for Carbaryl (Market Basket Data not included) and Table 6b: Summary of Market Basket Survey Data.

Aventis Comments: EPA/ BEAD reports a maximum of 84% crop treated for cranberries and an average of 39% crop treated for cranberries. Three years of data were obtained from the Cranberry Institute (memo from Gary Deziel, Manager of Research and Communication, Cranberry Institute.) These data show maximum acres treated 43 for 1992, 39%; 1996, 37%; and 1998, 36%. Based on these data and private conversations, the maximum percent crop treated for cranberries is 39% with an average of 37%.

Barley, oats, rye and cotton/ cottonseed are not supported by Aventis and should not be included in the risk assessment. A letter date May 7, 1999 to Ms. Kathryn Boyle confirmed Rhône Poulenc's (now Aventis CropScience) decision not to support the registration of carbaryl products on the commodities barley, oats, and rye. These uses have been deleted from our technical and end use product labels.

Residue Data Sources: The following data sources are more appropriate to use for the crops listed in the table, according to priority rules for use of residue data (Market Basket (MBS)> PDP> FDA> Field Trial (FT)> tolerance) and the Translation of Monitoring Data HED SOP 99.3 (March 26, 1999).

Food EPA Used More Appropriate Source Brussels Sprouts Cabbage FDA Lettuce MBS Cabbage Cabbage FDA Lettuce MBS Collards Mustard FT Spinach PDP Eggplant Pepper FDA Tomato MBS Endive Leaf lettuce FDA Spinach PDP Kale Mustard FT Spinach PDP Kohlrabi Cabbage FDA Broccoli MBS Mustard Greens Mustard FT Spinach PDP Paprika H. Pepper FDA Tomato MBS Chili Pepper H. Pepper FDA Tomato MBS Other Pepper H. Pepper FDA Tomato MBS Sweet Pepper S. Pepper FDA Tomato MBS Pimentos H. Pepper FDA Tomato MBS Strawberries Strawberry FDA Strawberry PDP Strawb. Juice Strawberry FDA Strawberry PDP Swiss Chard Celery PDP Spinach PDP Page 41 Residue Distribution Files RDF# 68 Almonds and RDF# 69 Chestnuts appear to have used the almond hull field trial data rather than the almond nutmeat field trial (mostly NDs) data for the residue values.

Page 44 Residue Distribution Files RDF# 86 to RDF# 92. Meat and milk. There is no clear indication or discussion anywhere in the document regarding the source of these residue data or how the values were derived (e. g., derived from theoretical animal diets or monitoring data). (see Discussion below). 44 Part II  Dietary and Water Exposure/ Risk Assessment SUPPORTING DISCUSSIONS Surface Water Concentrations In section 5.0, page 33 (Table 6), EPA has based its assumptions about concentrations of carbaryl in drinking water upon model simulations. The data from the registrant drinking water monitoring program provide the best estimate of concentrations of carbaryl in drinking water. This study uses the sampling design for acute endpoints recommended in industry/ EPA meetings during 1999 (weekly sampling during times of peak concentrations over a three year period). Twenty sites representing the highest carbaryl use areas were selected based on the information provided in Appendix I. Included are 16 sites in agricultural areas and 4 locations in urban areas. Samples were collected from the inlet and outlet water at each sampling interval. Outlet samples were only analyzed when residues were present in the inlet samples. The analytical method had a limit of quantification of 0.030 ppb and a limit of detection of 0.002 ppb.

Error! Reference source not found. summarizes the results of the monitoring at each of the 20 community water systems. The maximum concentration observed was 0.16 ppb (average of four samples, the highest was 0.18 ppb) in a finished water sample from the Deerfield community water system located on the River Raisin in Lenawee County, Michigan. There were only five other samples above the limit of quantification of 0.030 ppb. One was a raw water sample containing 0.31 ppb from the Little Potato Slough Mutual community water system near Lodi in San Joaquin County, California (the source is the Little Potato Slough). The corresponding finished water sample was 0.007 ppb. A second one was a raw water sample in Brockton, MA which contained 0.031 ppb. No detectable residues were found in the corresponding finish water sample. The last three samples were from the Shades Mountain plant of the Birmingham community water system on the Cahaba River in Jefferson County, Alabama . Two were raw and finished samples of 0.038 and 0.032 ppb at the same sampling interval in 2001. The other sample was 0.035 ppb in the raw water in a 2000 sample (the corresponding finished sample did not contain carbaryl residues. All residues were transient so the time weighted average concentration of carbaryl in each of the years was 0.005 ppb or less at all 20 community water systems. 45 Table 1.Summary of results from the carbaryl drinking water monitoring study.

Site Major Uses Maximum Concentration (ppt) TWA Conc. (ppt)* in Outlet Water Inlet Water Outlet Water 1999 2000 2001** 1999 2000 2001** 1999 2000 Manatee, FL citrus 9 3 ND 11 ND NA 1 1 West Sacramento, CA orchards, nuts 3 24 ND 3 10 NA 1 1 Lodi, CA orchards, nuts 12 31 ND 4 7 NA 1 1 Riverside, CA grapes, tree crops 8ND ND ND NANA 1 1 Lake Elsinore, CA citrus ND 3 6 NA NA Analysis Pending 1 1 Corona, CA citrus ND ND ND NA NA NA 1 1 Beaumont, TX various agricultural ND ND ND NA NA NA 1 1 Point Comfort, TX rice, tree crops 18 5ND ND NDNA 1 1 Penn Yan, NY grapes, apples ND 23 ND NA ND NA 1 1 Westfield, NY grapes, apples 21 5 ND ND 9 NA 1 1 Jefferson, OR vegetables, strawberries ND 10 ND NA ND NA 1 1 Coweta, OK pecans 4 ND *** ND NA *** 1 1 Pasco, WA apples, potatoes 2 3 ND ND ND NA 1 1 Manson, WA apples ND ND ND NA NA NA 1 1 Deerfield, MI vegetables 10 4 ND 160 ND NA 5 1 Brockton, MA cranberries 31 27 ND ND 3 NA 1 1 East Point, GA home and garden 18 18 4 3 8 ND 1 1 Midlothian, TX home and garden 14 ND 14 ND NA ND 1 1 Cary, NC home and garden 4ND ND ND NANA 1 1 Birmingham, AL home and garden 23 35 38 ND ND 32 1 1 * Annual Time Weighted Concentration, outlet values substituted for inlet values when available; values below the detection limit were considered to be half the detection limit. ** Results represent one to six months of sampling into the third year program. *** No results available for the third year of sampling. 46 ND Not detected. NA No outlet samples analyzed due to carbaryl residues not being detected in inlet samples.

Appropriateness of the Carbamate Market Basket Survey Data The Agency questions the appropriateness of the use of these data in several discussions of the dietary risk assessment. The CMBS Task Force met with EPA/ HED before the start of the study to review the purpose of the study and protocols for the study. The EPA assured the task force that the study data would be used in risk assessments, taking precedence over all other monitoring or field trial data available for those crops. A surrogation plan according to HED SOP 99.3 was also assured. The specific target of this study was to measure more realistic residues that consumer's are exposed to "at the plate". The study protocol was designed to mimic the typical consumer shopping at his/ her local grocery store and the preparation he would do at home before consuming or further cooking/ preparing the food. The PDP data is taken from distribution centers before the grocery stores are reached and some typical preparation is done. The CMBS data would therefore be expected to have somewhat lower and more realistic measures of residues consumers are exposed to. There is likely to be even further reduction of residues before the food is "put on the plate" by storing, cooking, slicing, peeling or other preparation. It would be very difficult to justify within the industry, further generation of these much needed data for other crops/ compounds if EPA decided at this late date that the data could not be used.

Secondary Residues Although residue distribution files are presented by the Agency in Attachment 1 of the Dietary Assessment Support Document for meat and milk commodities, there is no place in the document where these residue numbers and residue distribution files are discussed. Aventis neither can determine the source of the residue data was (monitoring or theoretical animal diets) nor how the data were translated or calculated. We request that a more detailed description of this process be provided to us.

Processing Factors EPA uses processing factors listed in a 1993 memo by S. Hummel. Examination of this document shows that the source of these processing factors is studies that were conducted in the 1980s or even earlier. As part of the Residue Chemistry DCI for carbaryl in the early 1990s, numerous residue processing studies were conducted along with residue (RAC) field trials. These studies are referenced in the Product and Residue Chemistry Support Document prepared by the EPA. These processing studies and the derived factors, which were conducted under GLP conditions to more recent specifications, are the factors that should be used in the current dietary risk assessment. A table of these factors is listed here. 47 Food Process Average PF Citrus Dried Pulp 1.46 Juice 0. 06 Oil 13.92 Molasses 0.47 Field Corn Small grits 0.25 Meal 0.25 Flour 0.25 Starch 0.25 Crude Oil 3. 38 Refined Oil 0. 25 Grapes Pasteurized Juice 0. 24 Wet Pomace 1.37 Dry Pomace 3.85 Processed Raisins 1. 37 Unprocessed Raisins 2. 17 Raisin Waste 4. 88 Olives Olive oil 0. 81 Peanuts Meal 0.29 Refined Oil 0. 29 Pome Juice 0. 40 Wet Pomace 1.26 Dry Pomace 3.70 Potatoes Wet Peel 1.00 Dry Peel 0.75 Flakes 0.75 Chips 0. 75 Rice Polished Rice 0.03 Hulls 2.37 Bran 0.36 Soybeans Hulls 0.35 Meal 0.22 Crude Oil 2. 71 Refined Oil 0. 005 Sunflowers Hulls 0.35 Meal 0.03 Crude Oil 0. 18 Refined Oil 0. 03 Tomatoes Juice 0. 52 Wet Pomace 1.74 Dry Pomace 2.89 Puree 1. 26 Paste 2. 01 Wheat Middlings 0.42 Shorts 0.83 Asp Grain Fractions 11.79 LG Flour 0.08 Patent Flour 0.10 Wheat Germ 0.65 Wheat Bran 1.03 48 Cooking Washing Factors EPA states several times that cooking/ washing studies would further reduce the anticipated residues used in the assessment and reduce the risk estimates. Aventis conducted a general literature search for studies such as this. A table of factors is listed followed by the references found in the general literature. Average cooking, washing and canning factors could be derived from these references and applied to the risk assessment as supported by these literature studies.

Food Process Reduction Reference Broccoli Cooking/ washing 55% 8 Cabbage Heads Cooking 90% 2 Cabbage Heads Washing 75% 2 Cauliflower Cooking/ washing 94% 4 Grapes Washing 49%; 85% 7 Green Beans Canning 100% 11 Green Beans Cooking/ blanching 81% 11 Green Beans Washing 52% 11 Okra Cooking 42%; 25% 1,14 Okra Cooking/ steaming 82% 1,14 Okra Washing 80%; 66%; 70% 1,14 Onions Washing 89%; 98%; 100% 9 Orchard Fruit Washing 50% 12 Peas Cooking/ boiling 85% 3 Peas Washing 70% 3 Spinach Canning 99.5% 10 Spinach Washing 70% 10 Tomatoes Peeling/ washing 99% 5,6 Tomatoes Puree/ catsup 98% 5,6 Tomatoes Washing 66%; 68%, 84% 5,6 1. Indian Journal of Plant Protection. 1996, 24, 86 89. 2. Pest Management and Econ. Zoology. 1994, 2, 131 134. 3. Plant Protection Bulletin. 1988, 40, 12 13. 4. Beitrage zur Trop. Land. Veter. 1982, 20, 89 95. 5. Indian Journal of Entomology. 1978, 40, 187 190. 6. Indian Journal of Entomology. 1973, 34, 31 34. 7. Indian Journal of Ag Sciences. 1978, 48, 179 183. 8. J. Ag. Food Chem. 1969, 15, 215 216. 9. J. Food Science Technology. 1978, 15, 215 216. 10. J. Ag. Food Chem. 1968, 16, 967 973. 11. J. Ag. Food Chem. 1968, 16, 962 966. 12. J. Assoc. Off. Anal. Che,. 1989, 72, 533 535. 13. Env. Health Criteria 1994, 153, 358pp. 49 14. Indian Journal of Ag Sciences. 1976, 45, 139 144. 15. Indian Journal of Env. Health Acute DWLOC EPA indicates there is no room in the risk cup for water and DWLOCs cannot be calculated. If a corrected acute RfD is used (no FQPA 10X), acute DWLOCs can be calculated as follows:

US Population: Acute RfD= 0.03 mg/ kg Exposure= 0.005937 mg/ kg (from EPA assessment without poultry and with CMBS data) 70 kg. Man, 2 liter consumption Acute DWLOC is 842ppb Children 1 6: Acute RfD= 0.03 mg/ kg Exposure= 0.008363 mg/ kg (from EPA assessment without poultry and with CMBS data) 10kg child, 1 liter consumption Acute DWLOC is 216ppb Aventis monitoring programs of raw surface drinking water have shown 0.16 ppb as the maximum encountered. NAWQA data shows 5 ppb as the maximum encountered in ground or surface water. These monitoring numbers would indicate there is no concern for dietary and drinking water exposure in an aggregate situation.

Chronic DWLOCs EPA indicates there is some concern for subpopulations for drinking water in the chronic scenarios. If a corrected chronic RfD is used (no FQPA 10X) chronic DWLOCs can be calculated as follows:

US Population: Chronic RfD= 0.01 mg/ kg Exposure = 0.000037 mg/ kg (from EPA assessment without poultry) 70kg man, 2 liter consumption Chronic DWLOC is 349 ppb Children 1 6: Chronic RfD= 0.01 mg/ kg Exposure= 0.000062 mg/ kg (from EPA assessment without poultry) 10kg child, 1 liter consumption Chronic DWLOC is 99 ppb 50 Aventis and NAWQA monitoring data averages are significantly less than the maximum values of 0.16 ppb and 5 ppb numbers cited above. There are no populations of concern for aggregate exposure to food and water for carbaryl. 51 Part III  Residue Chemistry Considerations Line by Line Review of the Residue Chemistry Information Included in the Human Health Risk Assessment Document for Carbaryl (June 19, 2001)

1.08 Data Needs/ Label Requirements Product Chemistry Data Gaps Page 95 Paragraph 3 Line 1 3 EPA comment: A review of the labels and supporting residue data indicate that several label amendments are required. Details are provided in the Product and Residue Chemistry Chapters (DP Barcode: D238151) dated October 17, 2000.

Aventis response: Most of these label amendments have already been made and approved by the EPA. See detailed information in the review of the Residue Chemistry Chapter below.

Page 96 Paragraph 7 Lines 1 2 EPA comment: Adequate residue data are available on olives provided that use directions for olives are amended to remove the statement allowing the use of summer oil as an adjuvant.

Aventis response: The statement allowing the use of summer oil as an adjuvant has already been deleted from the use directions for olives.

Page: 97 Paragraph: 2 Line 1 EPA comment: Additional data are required depicting carbaryl residue in/ on cotton gin byproducts.