USEPA 2000. Toxicological Review of Chlorine Dioxide and Chlorite, EPA/ 635/ R 00/ 007. http:// www. epa. gov/ IRIS/ toxreviews/ 0496 tr. pdf Warrington. P. 2002. Ambient Water Quality Guidelines for Chlorate  technical background report. Government of British Columbia, Ministry of Water, Land and Air Protection. ISBN 0 7726 4734 8. http:// wlapwww. gov. bc. ca/ wat/ wq/ BCguidelines/ chlorate. html Page 97 of 141 WHO. 2004. Chlorite and chlorate in Drinking Water. Background document for developing WHO Guidelines for Drinking water Quality, 20 pages. WHO/ SDE/ WSH/ 03.04/ 86 http:// www. who. int/ water_ sanitation_ health/ dwq/ chemicals/ en/ chloratechlorite. pdf Page 98 of 141 APPENDIX C RESIDUE CHEMISTRY CONSIDERATIONS for Sodium Chlorate ( 073301) as an active ingredient in conventional ( agricultural) pesticides Preface: Through a series of negotiations between members of SRRD and AD to coordinate Inorganic Chlorates and Chlorine Dioxide and Sodium Chlorite, with regards to the risk assessment for Inorganic Chlorates, the residue of concern from sodium chlorate exposures is chlorate by agreement. See Section 1.0 Executive Summary above.

Sodium chlorate is currently registered for preharvest and foliar applications as a defoliant or desiccant to the following food/ feed crops: dry beans, corn, cotton, flax, guar, chili peppers, potatoes, rice, safflower, sorghum ( grain), southern peas ( i. e., cowpeas), soybeans, and sunflowers. For food/ feed uses, sodium chlorate is formulated as a soluble concentrate ( SC) with the active ingredient ranging from 18% to 47.2%. Sodium chlorate may be applied using aircraft or ground spray equipment, including high and low volume equipment.

Uses of sodium chlorate as a defoliant or desiccant on cauliflower, cucurbit vegetables, and okra grown for seed only are considered non food uses. Uses of sodium chlorate on ornamental gourds and fallow lands are also considered non food uses. These non food uses will not be discussed further with regards to residue chemistry or dietary exposure/ risk considerations.

Under 40 CFR 180.1020 ( a) Sodium chlorate is exempt from the requirement of a tolerance for residues in or on the following raw agricultural commodities when used as a defoliant, desiccant, or fungicide in accordance with good agricultural practice: beans ( dry, edible), corn ( fodder), corn ( forage), corn ( grain), cottonseed, flaxseed, flax ( straw), guar beans, peas ( southern), peppers ( chili), potatoes, rice, rice ( straw), safflower ( grain), sorghum ( grain), sorghum ( fodder), sorghum ( forage), soybeans and sunflower seed.

Under 40 CFR 180.1020 ( b) A time limited exemption from the requirement of a tolerance is established for residues of the defoliant/ desiccant in connection with use of the pesticide under section 18 emergency exemptions granted by EPA. This exemption has been granted for wheat and will expire on 12/ 31/ 04. As requested by the Registration Division ( Sodium Chlorate Use Closure Memo Amendment; J. Guerry; dated 11/ 15/ 2004) the use of sodium chlorate on wheat is also addressed herein with the intention to convert the time limited exemption status to a permanent exemption from the requirement of a tolerance under 40 CFR. 1020 ( a). The proposed use rate is for a single application of sodium chlorate to wheat at 6 lbs ai/ A with a 3 day PHI.

No plant metabolism data have been submitted in support of the reregistration of sodium chlorate; however, no new plant metabolism data are required to support the established sodium chlorate tolerance exempts. Based on available published information ( Loomis et al., J. Am. Soc. Agron.; 25, 724 ( 1933)), sodium chlorate is highly soluble in water and is expected to readily absorb and translocate throughout plants. However, given the proposed use conditions, the means of translocation in treated plants may be substantially disrupted. Translocation of very small Page 99 of 141 amounts of chlorate ion ( ClO 3 b ) by plants ( translocation of significant amounts would be phytotoxic to plants) from the environment which may be present as a result of inorganic chlorate pesticide uses may occur. Terminal residues are expected to be primarily surface residues.

Since sodium chlorate is a strong oxidizing agent, depending on environmental factors, it is expected to be easily reduced to chloride and possibly chlorite in plants. Total redox conversion to these reduced species is not expected; hence, the terminal residues of sodium chlorate in/ on plants are likely chlorate ( ClO 3 b ), chlorite ( ClO 2 b ), and chloride ( Cl b ).

No ruminant, swine, or poultry metabolism or feeding data have been submitted in support of the reregistration of sodium chlorate; however, no new animal metabolism data are required to support the established sodium chlorate exemptions from the requirement of a tolerance. Based on published rat metabolism data ( Abdel Rahman et al, 1982, 1984b and 1985), terminal residues of sodium chlorate in animal tissues are expected to be chlorate ( ClO 3 b ), chlorite ( ClO 2 b ), and chloride ( Cl b ). Chlorate is readily absorbed from the digestive tract and is excreted as chlorate, chlorite, and chloride in urine primarily and feces. Within 72 hours, about 40% of the administered dose was excreted in the urine as chlorate ( ca. 13%), chlorite ( ca. 4%), and chloride ( ca. 20%) and about 2 4% was excreted in the feces in the same time period. Less than 1% of the administered dose was found in any of the tissues analyzed including kidney, liver, and skin.

Although some previous residue chemistry reviews for specific exemptions from the requirement of a tolerance have concluded that there is no reasonable expectation of transfer of residues to meat, milk, poultry or eggs in specific cases, re evaluation of the available crop field trial data taken as a whole, indicate that there is the possibility of detectable residues of sodium chlorate on animal feedstuffs at harvest. Hence, secondary residues of concern in meat, milk, poultry, and eggs are possible and; therefore, new ruminant and poultry feeding data are hereby required to support the reregistration of sodium chlorate. These data are considered confirmatory.

The analytical method used to support the established exemptions from the requirement of a tolerance is a non specific colorimetric method ( Branderis, J. Sci. Food Agric., 16, 558 ( 1965)), deemed acceptable for data collection. The method was originally developed to estimate residual chlorate concentrations in soil and as a rapid diagnostic test for chlorate toxicity in plants. Briefly, the method involves acid extraction, clean up by shaking with activated charcoal, and filtration. A solution of ortho toluidine in HCl is then added to the concentrated extract and the resulting color is measured at 448 nm for low concentrations and at 490 nm for higher concentrations of dye. The method is not specific for chlorate since it measures any oxidizing agent capable of oxidizing chloride ion to free chlorine. A standard curve is prepared with sodium chlorate for comparison. The lowest sensitivity of the method is estimated at 1 ppm based on available fortification data from field trials. Chloride does not interfere with the method but residues of chlorite, which might be present, may also be detected with this method. This method is hereby deemed adequate for enforcement of sodium chlorate exemptions from the requirement of a tolerance. [ Note: If needed, a more selective HPLC method (" Determination of Residues of Page 100 of 141 Sodium Chlorate in Potatoes", Method # S57023, 4/ 2/ 91) is available for the detection of sodium chlorate residues in or on raw agricultural commodities ( RACs).]

New reference standards must be supplied to the EPA National Pesticide Standards Repository.

Only crop field trial data have been submitted to support the reregistration of sodium chlorate. No storage stability or processing data are available. The available crop field trial data have been re evaluated herein. No additional plant magnitude of the residue or storage stability data are required to support the reregistration of sodium chlorate. Page 101 of 141 Table C. 1. Residue Chemistry Science Assessment for Reregistration of Sodium Chlorate ( 073301) as an active ingredient in conventional ( agricultural) pesticides GLN Data Requirements Current Tolerances ( ppm) [ § 180.1020] Additional Data Needed? Citations 1 860.1200: Directions for Use NA No 860.1300: Nature of the Residue  Plants NA No 00062497, 00066805 860.1300: Nature of the Residue  Animals NA No None 860.1340: Residue Analytical Method NA No 00049610, 00066802, 00066804, 00066808, 00066809, 00066810, 00123747, 00124680, 00135224 860.1360: Multiresidue Method NA No None 860.1380: Storage Stability Data NA No None 860.1400: Magnitude of the Residue  Water, Fish and Irrigated Crops None No None 860.1460: Magnitude of the Residue  Food Handling None No None 860.1480: Magnitude of the Residue  Meat, Milk, Poultry, Eggs  Cattle fat, meat, and meat byproducts None Yes 2 None  Goat fat, mean and meat byproducts  Horse fat, meat and meat byproducts  Sheep fat, meat and meat byproducts  Milk  Eggs and the Fat, Meat and Meat Byproducts of Poultry 860.1500: Crop Field Trials 3  Beans ( dried, edible) Exempt No  Corn ( fodder, forage, grain) Exempt No  Cottonseed Exempt No  Flaxseed and Flax ( straw) Exempt No 00136326  Guar beans Exempt No 00136388 Table C. 1. Residue Chemistry Science Assessment for Reregistration of Sodium Chlorate ( 073301) as an active ingredient in conventional ( agricultural) pesticides GLN Data Requirements Current Tolerances ( ppm) [ § 180.1020] Additional Data Needed? Citations 1 Page 102 of 141  Peas ( southern) Exempt No 00128727  Peppers ( chili) Exempt No 00116554  Potatoes Exempt No 42464201, 42930601  Rice and Rice straw Exempt No 00159210  Safflower ( grain) Exempt No None  Sorghum ( grain, fodder, forage) Exempt No 00123727  Soybeans Exempt No 00128727  Sunflower seed Exempt No 00135224  Wheat Exempt No 00136326 860.1520: Processed Food/ Feed NA No None 860.1850: Confined Accumulation in Rotational Crops NA No None 860.1650: Submittal of Analytical Reference Standards NA Yes 4 None 860.1900: Field Accumulation in Rotational Crops NA No None 1 Only data considered primary sources of information to support the reregistration of sodium chlorate are included here. All other available data are considered supplemental. 2 New ruminant and poultry feeding studies are required. 3 Sodium chlorate is exempt from the requirement of a tolerance for residues in or on the listed raw agricultural commodities when used as a defoliant, desiccant, or fungicide in accordance with good agricultural practice [ 40 CFR 180.1020] 4 Replenish standards as requested by the repository.

860.1300 Nature of the Residue  Plants No plant metabolism data have been submitted in support of the reregistration of sodium chlorate; however, no new plant metabolism data are required to support the established sodium chlorate tolerance exempts. Based on available published information ( Loomis et al., J. Am. Soc. Agron.; 25, 724 ( 1933)), sodium chlorate is highly soluble in water and is expected to readily absorb and translocate throughout plants. However, given the proposed use conditions, the means of Page 103 of 141 translocation in treated plants may be substantially disrupted. Translocation of very small amounts of chlorate ion ( ClO 3 b ) by plants ( translocation of significant amounts would be phytotoxic to plants) from the environment which may be present as a result of inorganic chlorate pesticide uses may occur. Terminal residues are expected to be primarily surface residues.

Since sodium chlorate is a strong oxidizing agent, depending on environmental factors, it is expected to be easily reduced to chloride and possibly chlorite in plants. Total redox conversion to these reduced species is not expected; hence, the terminal residues of sodium chlorate in/ on plants are likely chlorate, chlorite, and chloride.

860.1300 Nature of the Residue  Livestock No ruminant, swine, or poultry metabolism or feeding data have been submitted in support of the reregistration of sodium chlorate; however, no new animal metabolism data are required to support the established sodium chlorate exemptions from the requirement of a tolerance. Based on published rat metabolism data ( Abdel Rahman et al, 1982, 1984b and 1985), terminal residues of sodium chlorate in animal tissues are expected to be chlorate ( ClO 3 b ), chlorite ( ClO 2 b ), and chloride ( Cl b ). Chlorate is readily absorbed from the digestive tract and is excreted as chlorate, chlorite, and chloride in urine primarily and feces. Within 72 hours, about 40% of the administered dose was excreted in the urine as chlorate ( ca. 13%), chlorite ( ca. 4%), and chloride ( ca. 20%) and about 2 4% was excreted in the feces in the same time period. Less than 1% of the administered dose was found in any of the tissues analyzed including kidney, liver, and skin.

Metabolism  Rat The metabolism and distribution of chlorine dioxide ( ClO 2 ), chlorite ion ( ClO 2 b ), and chlorate ion ( ClO 3 b ) were studied in rats ( Abdel Rahman et al, 1982, 1984b, 1985). Three groups of male Sprague Dawley rats ( 4/ group) were administered a single oral ( gavage) dose of one of the compounds which were 36Cl radiolabeled. Expired air, fecal and urine samples were collected over 72 hours. The 36Cl activity in these samples was measured and the radioactivity in the urine was identified as chlorate ( ca. 13% of the administered dose), chlorite ( ca. 4% of the administered dose) and chloride ( ca. 20% of the administered dose). At 72 hours, the rats were killed and the distribution of 36Cl activity in tissues was determined ( see Table C. 2). Total radioactivity in each of the tissues examined was < 1% of the initial dose. Page 104 of 141 Table C. 2. Distribution of radioactivity in rat tissues after dosing with 36Cl labeled chlorine dioxide, potassium chlorite, or potassium chlorate.

Tissue Percentage of initial dose 1 Chlorine dioxide ( 36ClO2) Chlorite ( 36ClO2 b ) Chlorate ( 36ClO3 b )

Plasma 0.72 ± 0.02 0.55 ± 0.038 0.68 ± 0.09 Packed cells  2 0.63 ± 0.11 0.23 ± 0.02 Whole blood  0.64 ± 0.01 0.57 ± 0.05 Kidney 0.81 ± 0.15 0.30 ± 0.06 0.42 ± 0.07 Lung 0.74 ± 0.15 0.37 ± 0.04 0.45 ± 0.07 Stomach 0.70 ± 0.15 0.43 ± 0.07 0.46 ± 0.05 Duodenum 0.29 ± 0.07 0.31 ± 0.01 0.34 ± 0.04 Ileum 0.48 ± 0.09 0.17 ± 0.03 0.21 ± 0.02 Liver 0.38 ± 0.09 0.06 ± 0.03 0.20 ± 0.03 Spleen 0.25 ± 0.04 0.22 ± 0.02 0.29 ± 0.04 Bone marrow 0.16 ± 0.03 0.09 ± 0.03 0.15 ± 0.03 Testes  0.39 ± 0.04 0.45 ± 0.07 Skin  0.38 ± 0.06 0.42 ± 0.10 Carcass  0.25 ± 0.04 0.21 ± 0.02 1 Value represents the mean ± SE as percentage of the initial dose from four rats per treatment after 72 hr. 2 Not Determined 860.1340 Residue Analytical Methods The analytical method used to support the established exemptions from the requirement of a tolerance is a non specific colorimetric method ( Branderis, J. Sci. Food Agric., 16, 558 ( 1965)), deemed acceptable for data collection. The method was originally developed to estimate residual chlorate concentrations in soil and as a rapid diagnostic test for chlorate toxicity in plants. Briefly, the method involves acid extraction, clean up by shaking with activated charcoal, and filtration. A solution of ortho toluidine in HCl is then added to the concentrated extract and the resulting color is measured at 448 nm for low concentrations and at 490 nm for higher concentrations of dye. The method is not specific for chlorate since it measures any oxidizing agent capable of oxidizing chloride ion to free chlorine. A standard curve is prepared with sodium chlorate for comparison. The sensitivity of the method is estimated at 1 ppm based on available fortification data from field trials. Chloride does not interfere but residues of chlorite, which might be present, may also be detected with this method. This method is hereby deemed adequate Page 105 of 141 for enforcement of sodium chlorate exemptions from the requirement of a tolerance. A more selective HPLC method (" Determination of Residues of Sodium Chlorate in Potatoes", Method # S57023, 4/ 2/ 91) is available for the detection of sodium chlorate residues in or on raw agricultural commodities ( RACs).

860.1360 Multiresidue Methods It does not appear that the registrant has submitted multiresidue method studies. Sodium chlorate is not listed in the FDA PESTDATA database dated 11/ 01 ( PAM Volume I, Appendix I). However, sodium chlorate would not be expected to be recovered by the PAM I multiresidue methods. No additional multiresidue methods data are required to support the reregistration of sodium chlorate.

860.1380 Storage Stability No storage stability data have been submitted in support of the reregistration of sodium chlorate. However, the available data continue to uphold the established sodium chlorate exemptions from the requirement of a tolerance, and therefore, no new storage stability data are required to support the reregistration of sodium chlorate.

860.1400 Water, Fish, and Irrigated Crops Sodium chlorate is not presently registered for direct use on water and aquatic food and feed crops other than as a desiccant on rice. Since sodium chlorate is used to desiccate green foliage and weeds present in rice fields to increase harvest efficiency, residues of concern are not expected to be occurred in water, fish, and irrigated crops from the use of sodium chlorate as a desiccant on rice. Therefore, no residue chemistry data are required under these guideline topics.

860.1460 Food Handling Sodium chlorate is not presently registered for use in food handling establishments; therefore, no residue chemistry data are required under these guideline topics.

860.1480 Meat, Milk, Poultry, and Eggs No ruminant, swine or poultry feeding studies have been submitted in support of the reregistration of sodium chlorate. Although some previous residue chemistry reviews for exemptions from the requirement of a tolerance have concluded that there is no reasonable expectation of transfer of residues to meat, milk, poultry or eggs in specific cases, re evaluation of the available crop field trial data taken as a whole, indicate that there is the possibility of detectable residues of sodium chlorate on animal feedstuffs at harvest. Hence, secondary residues of sodium chlorate in meat, milk, poultry, and eggs are possible and; therefore, new ruminant and poultry feeding data are hereby required to support the reregistration of sodium chlorate. Page 106 of 141 Table C. 3. Calculation of the highest average and maximum theoretical dietary burden for beef/ dairy cattle and poultry from the maximum registered use rates of sodium chlorate ( 073301) as an active ingredient in conventional ( agricultural) pesticides.

Feed Commodity % Dry Matter % Diet Residue Estimate ( ppm) Dietary Contribution 1 ( ppm) Max. Feed Per Day on a Dry Wt. Basis ( Kg) Dietary Exposure Estimate ( mg)

Highest Ave Max Highest Ave Max Highest Ave Max Beef and Dairy Cattle Cowpea forage 30 40 100 2 300 2 133 400 Cowpea hay 86 20 100 2 300 2 23 70 Sorghum grain 86 40 40 3 70 3 19 33 Total Burden 175 500 9.1 5 1600 4600 Poultry Sorghum grain Not Used 1 80 40 3 70 3 32 56 Rice bran 20 40 4 70 4 8 14 Total Burden 40 70 1 Dietary Contribution for Cattle = ( Residue Estimate in ppm ÷ % DM) x % Diet Dietary Contribution for Poultry = Residue Estimate in ppm x % Diet 2 Based on the available straw ( flax, oat, wheat, rice) and forage ( guar plants, sorghum stalks, soybean forage) data, maximum residues of sodium chlorate in/ on straw and forage livestock feedstuffs harvested 3 7 days after treatment with sodium chlorate at the maximum use rate permitted on forage crops ( 1 or 2 applications; 7.5 lbs ai/ A/ application) are not expected to exceed 300 ppm at the point of harvest. On average, residues in/ on straw and forage livestock feedstuffs should not exceed 100 ppm when harvested 7 14 days after foliar treatment with sodium chlorate at the maximum use rate permitted on forage crops ( 1 or 2 applications; 7.5 lbs ai/ A/ application). 3 Based on the available sorghum field trial data alone, maximum residues in/ on sorghum grain harvested 7 14 days after treatment with sodium chlorate at the maximum use rate for sorghum ( 1 application; 7.5 lbs ai/ A; 7 day PHI) are not expected to exceed 70 ppm. On average, residues in/ on sorghum grain harvested 7 14 days after treatment with sodium chlorate at the maximum use rate on sorghum ( 1 application; 7.5 lbs ai/ A; 7 day PHI) are not expected to exceed 40 ppm. 4 Translated from sorghum grain estimate. 5 Cattle eat a maximum of 9.1 kg of feed per day on a dry wt. basis ( Update of Livestock Feed Consumption, 1993) Page 107 of 141 The highest average residues of chlorate ( excluding percent crop treated data) in meat, poultry, and eggs are expected to be < 4 ppm and in milk are expected to be < 0.5 ppm based on the following information and assumptions:

° The highest average theoretical dietary burden for livestock is 175 ppm for cattle feed on a dry wt. basis ° Cattle eat a maximum of 9.1 kg of feed per day on a dry wt. basis ( Update of Livestock Feed Consumption, 1993); hence, the highest average theoretical dietary exposure for sodium chlorate to livestock is 1600 mg per day ° Based on the available rat metabolism data, < 1% of the initial dose of chlorate is expected to be incurred in animal tissues 72 hours after exposure ( Abdel Rahman et al, 1982, 1984b and 1985); hence < 16 mg is expected to be incurred in any livestock tissue of interest ° Assuming that kidneys have the lowest weight of the organs/ tissues of interest ( other than milk) in livestock ( i. e., compared to meat, liver, fat, and eggs) ° Assuming that the average weight of cattle kidneys is about 4 kg ( Update of Livestock Feed Consumption, 1993; cattle kidneys weigh 3.6 4.5 kg) ° Assuming that the average milk production per day is about 30 kg ( Frank, 2002; milk production is 50 90 lb milk/ cow/ day)

Calculations:

( Highest Average Theoretical Dietary Exposure ( 1600 mg) x Percent of Dietary Exposure Expected in Organs (< 1%) Average Weight of the Organ/ Tissue of Interest ( Kidney at 4 Kg or Milk at 30 Kg)

Highest Average Residue Estimate in Meat, Poultry, and Eggs = < 4 ppm Highest Average Residue Estimate in Milk = < 0.5 ppm Page 108 of 141 The maximum residues of chlorate ( excluding percent crop treated data) in meat, poultry, and eggs are expected to be < 12 ppm and in milk are expected to be < 2 ppm based on the following information and assumptions:

° The maximum theoretical dietary burden for livestock is 500 ppm for cattle feed on a dry wt. basis ° Cattle eat a maximum of 9.1 kg of feed per day on a dry wt. basis ( Update of Livestock Feed Consumption, 1993); hence, the highest average theoretical dietary exposure for sodium chlorate to livestock is 4600 mg per day ° Based on the available rat metabolism data, < 1% of the initial dose of chlorate is expected to be incurred in animal tissues 72 hours after exposure ( Abdel Rahman et al, 1982, 1984b and 1985); hence < 46 mg is expected to be incurred in any livestock tissue of interest ° Assuming that kidneys have the lowest weight of the organs/ tissues of interest ( other than milk) in livestock ( i. e., compared to meat, liver, fat, and eggs) ° Assuming that the average weight of cattle kidneys is about 4 kg ( Update of Livestock Feed Consumption, 1993; cattle kidneys weigh 3.6 4.5 kg) ° Assuming that the average milk production per day is about 30 kg ( Frank, 2002; milk production is 50 90 lb milk/ cow/ day)

Calculations:

( Maximum Theoretical Dietary Exposure ( 4600 mg) x Percent of Dietary Exposure Expected in Organs (< 1%) Average Weight of the Organ/ Tissue of Interest ( Kidney at 4 Kg or Milk at 30 Kg)

Maximum Residue Estimate in Meat, Poultry, and Eggs = < 12 ppm Maximum Residue Estimate in Milk = < 2 ppm Page 109 of 141 860.1500 Crop Field Trials Available crop field trial data deemed the primary sources of information to support the reregistration of sodium chlorate are briefly discussed below and summarized in Table C. 5. All other available crop field trial data are considered supplemental and will not be discussed further. No additional crop field trial data are required to support the reregistration of sodium chlorate.

The subject data, except the potato tuber data, were all collected using the colorimetric method ( Branderis, J. Sci. Food Agric., 16, 558 ( 1965)), deemed acceptable for data collection and enforcement of the established sodium chlorate exemptions from the requirement of a tolerance. The potato tuber data were collected with a more selective HPLC method (" Determination of Residues of Sodium Chlorate in Potatoes", Method # S57023, 4/ 2/ 91) deemed adequate for data collection. The lowest limits of quantitation ( LOQs) of these methods is estimated at 1 ppm.

Based on the available flax, guar, southern pea, soybean, and sunflower field trial data no detectable residues of sodium chlorate (< 1 ppm) are expected in/ on dry beans, guar beans, southern peas, soybeans, flaxseed, safflower seed, and sunflower seed at the point of harvest from the maximum use rate of sodium chlorate on dry beans, guar, southern peas, soybeans, flax, safflower, and sunflower ( 1 application; 7.5 lbs ai/ A; 7 day PHI). Furthermore, no detectable residues of sodium chlorate (< 1 ppm) are expected in/ on cottonseed at the point of harvest from the maximum use rate of sodium chlorate on cotton ( 2 applications, 7.5 lbs ai/ A/ application; 7 day PHI). Any residues which might be detected at the point of harvest are expected to be primarily surface residues which would be substantially removed prior to the point of consumption.

Based on the available chili pepper field trial data, it is possible that detectable residues of sodium chlorate ( ca. 13 ppm) might be found on the surface of unwashed chili peppers treated with sodium chlorate at the maximum use rate of sodium chlorate on chili peppers ( 1 application; 12.5 lbs ai/ A/ application; 10 day PHI). However, these residues are primarily surface residues present at the point of harvest which would be substantially removed by washing (< 1 ppm) prior to the point of consumption.

Based on the available potato field trial data, no detectable residue of sodium chlorate (< 1 ppm) are expected in/ on potato tubers at the point of harvest from the maximum use rate of sodium chlorate on potatoes ( 1 application; 12.5 lbs ai/ A; 7 day PHI). As demonstrated by the chili pepper field trial data, any residues present at harvest are expected to be primarily surface residues which would be substantially removed by washing prior to the point of consumption.

Based on the available oat, rice, sorghum, and wheat field trial data, it is possible that detectable residues of sodium chlorate ( ca. 70 ppm ( maximum) as demonstrated by sorghum grain) might be found on the surface of cereal grains retaining their outer hulls at harvest ( such as oats and sorghum) from the maximum use rate of sodium chlorate on rice and sorghum ( 1 application; 7.5 lbs ai/ A; 7 day PHI) and wheat ( 1 application; 6 lbs ai/ A; 3 day PHI). However, once the outer hulls are removed ( either at harvest or during processing), no detectable residues of sodium chlorate Page 110 of 141 (< 1 ppm) are expected in/ on cereal grains such as rice and wheat ( as demonstrated by rice w/ out hulls and wheat grain data).

Based on the available sorghum field trial data alone, maximum residues in/ on sorghum grain harvested 7 14 days after treatment with sodium chlorate at the maximum use rate for sorghum ( 1 application; 7.5 lbs ai/ A; 7 day PHI) are not expected to exceed 70 ppm. On average, residues in/ on sorghum grain harvested 7 14 days after treatment with sodium chlorate at the maximum use rate on sorghum ( 1 application; 7.5 lbs ai/ A; 7 day PHI) are not expected to exceed 40 ppm.

Translating the available sorghum field trial data to corn, residues of sodium chlorate are not expected to exceed 20 ppm ( ca. 10 ppm on average) in/ on corn grain at the point of harvest from the maximum use rate of sodium chlorate on corn ( 1 application, 7.5 lbs ai/ A; 14 day PHI). As demonstrated by the chili pepper field trial data, any residues present at harvest are expected to be primarily surface residues which would be substantially removed by washing prior to the point of consumption. Hence, residues of sodium chlorate in/ on sweet corn after washing and prior to consumption would not be expected to exceed 1 ppm.

Based on the available straw ( flax, oat, wheat, rice) and forage ( guar plants, sorghum stalks, soybean forage) data, maximum residues of sodium chlorate in/ on straw and forage livestock feedstuffs harvested 3 7 days after treatment with sodium chlorate at the maximum use rate permitted on forage crops ( 1 or 2 applications; 7.5 lbs ai/ A/ application) are not expected to exceed 300 ppm at the point of harvest. On average, residues in/ on straw and forage livestock feedstuffs should not exceed 100 ppm when harvested 7 14 days after foliar treatment with sodium chlorate at the maximum use rate permitted on forage crops ( 1 or 2 applications; 7.5 lbs ai/ A/ application).

Chili peppers: MRID 00116554 Chili pepper plants were treated with a single application of sodium chlorate at 8 or 16 lb ai/ A. Chili pepper samples were collected 7 21 days after treatment. Residues of chlorate in/ on chili pepper samples were < 0.1 to 13 ppm. After washing the treated chili peppers with water, residues of chlorate were all < 0.1 ppm.

Flax, Oats, Wheat: MRID 00136326 Flax, oats, and wheat plots were treated with a single application of sodium chlorate at 6 or 12 lbs ai/ A. Grain and straw samples were collected 3 10 days after treatment. Residues of chlorate in/ on flax grain/ straw, wheat grain/ straw and oat straw samples were < 2 ppm. Residues of chlorate in/ on oat grain samples treated at 6 and 12 lbs ai/ A were 10 36 ppm ( 20 ppm average) and < 2 125 ppm ( 80 ppm average), respectively.

Guar: MRID 00136388 Guar plots were treated with a single application of sodium chlorate at 6 or 12 lbs ai/ A. Seed and plant samples were collected 2 14 days after treatment. Residues of chlorate in/ on seed samples < 10 ppm. Residues of chlorate in/ on plant samples were 18 266 ppm. Page 111 of 141 Potatoes: MRID 42464201 ( Chromatograms  MRID 42930601) Potato plants were treated with a single application of sodium chlorate at 9 lbs ai/ A. Potato tubers were collected 7 10 days after treatment. Residues of chlorate in/ on potato tubers were < 1.0 ppm.

Rice: MRID 00159210 Rice plots were treated with a single application of sodium chlorate at 6 or 12 lbs ai/ A. Grain w/ out hulls, grain with hulls, and straw samples were collected 2 9 days after treatment.

While residues of chlorate in/ on grain with hulls collected 8 days after treatment were 7 160 ppm, residues in/ on grain w/ out hulls collected 7 days after treatment were essentially nil ( reported as 0.0 ppm). Detectable residues ( 0.0 30 ppm) were reported in/ on grain w/ out hulls collected 2 days after treatment at 12 lbs ai/ A.

Residues of chlorate in/ on straw samples ranged from < 1 ppm to 44 ppm from treatment at 6 lbs ai/ A and from < 1 ppm to 438 ppm from treatment at 12 lbs ai/ A.

Sorghum: MRID 00123727 Sorghum plots were treated with a single application fo sodium chlorate at 3, 6, and 12 lbs ai/ A. Grain and stalk samples were collected 2 14 days after application.

Residues of chlorate in/ on grain samples collected 7 and 14 days after treatment at 6 lbs ai/ A were 44 69 ppm ( 59 ppm average) and 8 21 ppm ( 13 ppm average), respectively. Residues of chlorate in/ on grain samples collected 7 and 14 days after treatment at 12 lbs ai/ A were 83 132 ppm ( 106 ppm average) and 13 40 ppm ( 30 ppm average), respectively.

Residues of chlorate in/ on stalk samples collected 7 14 days after treatment at 6 lbs ai/ A were essentially nil ( 0.0 ppm) to 51 ppm ( 21 ppm average). Residues of chlorate in/ on stalk samples collected 7 14 days after treatment at 12 lbs ai/ A were essentially nil ( 0.0 ppm) to 352 ppm ( 117 ppm average).

Southern Peas ( cowpeas): MRID 00128727 Southern pea plots were treated with a single application of sodium chlorate at 6 lbs ai/ A. Shelled pea samples were collected 4 or 5 days after treatment. Some of the raw shelled peas were processed into frozen peas. Residues of sodium chlorate were < 0.3 ppm in/ on all samples.

Soybeans: MRID 00128727 Soybean plots were treated with a single application of sodium chlorate at 6 or 12 lbs ai/ A. Soybean and foliage samples were collected 2 14 days after treatment. Residues of chlorate in/ on soybeans collected 7 14 days after treatment were < 5.0 ppm. Residues of chlorate in/ on soybean foliage collected 7 days after treatment at 6 or 12 lbs ai/ A were as high as 153 ppm and 526 ppm, respectively. Residues of chlorate in/ on soybean forage collected 14 days after treatment at 6 or 12 lbs ai/ A were as high as 100 ppm and 318 ppm, respectively. Page 112 of 141 Sunflower Seeds: MRID 00135224 Sunflower plots were treated with a single application of sodium chlorate at 3, 6, or 12 lbs ai/ A. Seed samples were collected 2 14 days after treatment. Residues of sodium chlorate in/ on all samples were essentially nil ( reported as 0 ppm) except 1 seed sample collected 4 days after treatment at 12 lbs ai/ A which showed residues of 10 ppm ( average of 3 replicates; one replicate showed residues of 30 ppm). Page 113 of 141 Table C. 4. Summary of available crop field trial data. Note: Guar, rice, sorghum, soybean, and sunflower data are truncated in this table. Data, except wheat grain data, collected less than 7 days after treatment have been intentionally excluded in this table but may be included in the brief discussions above.

Matrix Crop Application Rate ( lbs ai/ A) PHI ( days) Residues ( ppm)

Maximum 1 Estimated Average 2 Vegetable Chili pepper ( raw) 8 or 16 7 21 13 Not Calculated Chili pepper ( washed) < 0.1 < 0.1 Potato tuber 9 7 10 < 1 < 1 Seed/ Bean Flax 6 10 < 2 < 2 Guar 7 < 10 < 10 Southern pea 4 5 < 0.3 < 0.3 Soybean 7 14 < 5 < 5 Sunflower 7 14 essentially nil ( zero) essentially nil ( zero)

Flax 12 10 < 2 < 2 Guar 7 14 < 10 < 10 Soybean 7 14 < 5 < 5 Sunflower 7 14 essentially nil ( zero) essentially nil ( zero)

Cereal Grain Oat 6 8 36 20 Rice w/ out hulls 7 9 essentially nil ( zero) essentially nil ( zero)

Rice with hulls 8 13 9.7 Sorghum 7 69 59 14 21 13 Wheat 3 9 < 2 < 2 Oat 12 8 125 80 Rice w/ out hulls 7 9 essentially nil ( zero) essentially nil ( zero)

Rice with hulls 8 160 93 Page 114 of 141 Sorghum 7 132 106 14 40 30 Wheat 3 9 < 2 < 2 Straw Flax, Oat, Wheat 6 or 12 3 10 < 2 < 2 Rice 6 7 9 44 11 12 7 9 438 75 Forage Guar plants 6 7 58 40 12 7 14 106 70 Sorghum stalk 6 7 14 51 21 12 7 14 352 117 Soybean forage 6 7 153 Reviewer Cannot Determine 14 100 12 7 526 14 318 1 Maximum residue as reported in the data submission. 2 Estimated Average calculated by the reviewer.

860.1520 Processed Food and Feed No processing data have been submitted regarding residues of sodium chlorate in/ on processed food/ feed commodities ( corn, cotton, flaxseed, potato, rice, safflower, sorghum, and wheat). However, since no significant residues were found in the raw agricultural commodities subject to processing, it is unlikely that significant residues will occur in the processed fractions.

860.1650 Submittal of Analytical Reference Standards As of 8/ 11/ 04, an analytical reference standard for sodium chlorate is not available at the EPA National Pesticide Standards Repository.

860.1850 Confined Accumulation in Rotational Crops No data have been submitted regarding residues of sodium chlorate in/ on confined accumulation in rotational crops. Page 115 of 141 860.1900 Field Accumulation in Rotational Crops No data have been submitted regarding residues of sodium chlorate in/ on field accumulation in rotational crops. Page 116 of 141 RESIDUE CHEMISTRY REFERENCES Studies Considered Primary Sources of Information and Used in the Assessment PUBLISHED Abdel Rahman MS, Couri D, Bull RJ. 1982. Metabolism and pharmacokinetics of alternate drinking water disinfectants. Environ Health Perspect. 46: 19 23.

Abdel Rahman MS, Couri D, Bull RJ. 1984b. The Kinetics of Chlorite and Chlorate in the Rat. Journal of the American College of Toxicology, 3( 4): 261 267.

Abdel Rahman MS, Couri D, Bull RJ. 1985. The kinetics of chlorite and chlorate in rats. J Environ Pathol Toxicol Oncol. 6( 1): 97 103.

Frank, G. 2002. Cost of Milk Production per Hundredweight Equivalent in Milk Sold per Cow Ranges. Wisconsin Dairy Data. Fact Sheet 2002 01. Center for Dairy Profitability. Univ. Wisconsin Extension Service. Oct. 2002.

UNPUBLISHED 49610 Rhone Poulenc Chemical Company ( 1959) Method of Analysis for Chlorates. ( Unpublished study received Jan 4, 1962 under 359 400; CDL: 119511 B)

62497 Pernert, J. C. ( 1960) On the Possibility of Toxic Residues following Cotton Defoliation by Chlorate. ( Unpublished study received Dec 18, 1969 under 0F0926; prepared by Hooker Chemical Corp., submitted by Fenrich Vincent Associates, Manhasset, N. Y.; CDL: 093232 G)

66802 Fenrich Vincent Associates ( 1969) Analytical Methods and Results of Tests on the Amount of Residue Remaining in or on Raw Cottonseed When an ( Inert Ingredient) has Been Used on the Cotton Plant. Unpublished study; 14 p.

66804 Gauditz, I. ( 1959) The Results of Tests on the Amount of Residue Remaining, Including a Description of the Analytical Methods Used: ( Penco De fol ate). ( Unpublished study received May 30, 1970 under 0F0926; submitted by Fenrich Vincent Associates, Manhasset, N. Y.; CDL: 091580 O)

66805 Banderis, A. ( 1965) Colorimetric Determination of chlorate in soil and plant extracts. Journal of the Science of Food and Agriculture 16( Sep): 558 564. ( Also In unpublished submission received May 30, 1970 under 0F0926; submitted by Fenrich Vincent Associates, Manhasset, N. Y.; CDL: 091580 P) Page 117 of 141 66808 Peniston, Q. P. ( 1968) Letter sent to E. H. Karr dated Jan 3, 1968: Determination of sodium chlorate residues on cottonseed: Report # 3. ( Unpublished study received May 30, 1970 under 0F0926; prepared by Food, Chemical & Research Laboratories, Inc., submitted by Fenrich Vincent Associates, Manhasset, N. Y.; CDL: 091580 T)

66809 Peniston, Q. P. ( 1968) Letter sent to E. H. Karr dated Jul 30, 1968: Determination of sodium chlorate residues in ground cottonseed report # 4: Lab. No. 5639. ( Unpublished study received May 30, 1970 under 0F0926; prepared by Food, Chemical & Re search Laboratories, Inc., submitted by Fenrich Vincent Associates, Manhasset, N. Y.; CDL: 091580 U)

66810 Peniston, Q. P. ( 1969) Letter sent to E. H. Karr dated Feb 18, 1969: Further studies on determination of sodium chlorate residues in ground cottonseed report # 5: Lab. No. 5879; prepared by Food, Chemical & Research Laboratories, Inc. Unpublished study; 2 p.

116554 California, Dept. of Agriculture ( 1971) Application of Shed A Leaf on Chili Peppers: Results. ( Compilation; unpublished study received Oct 13, 1972 under 2E1286; CDL: 091822 A)

123747 Banderis, A. ( 1965) Colorimetric determination of chlorate in soil and plant extracts. J. Sci. Ef. Agric. 16( Sep): 558. ( Also In unpublished submission received 1965 under 3E1386; submitted by Interregional Research Project No. 4, New Brunswick, NJ; CDL: 093699 B)

124680 Roth, F. ( 1967) A test for chlorate residues. Bulletin of Environmental Contamination & Toxicology 2( 4): 251 254. ( Also In unpublished submission received Jun 23, 1972 under 2E1286; submitted by California, Dept. of Agriculture, Sacramento, CA; CDL: 094665 A)

128727 Interregional Research Project No. 4 ( 1983) The Results of Tests on the Amount of Residues Remaining in or on Southern Peas, Including a Description of the Analytical Method Used. ( Compilation; unpublished study received Jun 10, 1983 under 3E2910; CDL: 071699 A)

135224 Interregional Research Project No. 4 ( 1975) The Results of Tests on the Amount of Sodium Chlorate Residue Remaining in or on Sunflower Seeds, Including a Description of the Analytical Method Used. ( Compilation; unpublished study received Jul 1, 1976 under 6E1825; CDL: 097356 A)

136326 Interregional Research Project No. 4 ( 1978) The Results of Tests on the Amount of Sodium Chlorate Residue Remaining in or on Flax, Oats, and Wheat Including a Description of the Analytical Method Used. ( Compilation; unpublished study received Oct 20, 1978 under 9E2142; CDL: 097460 A)

136388 Interregional Research Project No. 4 ( 1979) Results of Tests Concerning the Amount of Sodium Chlorate Residue Remaining in or on Guar Including a Description of the Analytical Method Used. ( Compilation; unpublished study received Jun 15, 1979 under 9E2220; CDL: 098331 A) Page 118 of 141 159210 Kerr McGee Chemical Corp. ( 1975) Sodium Chlorate on Rice: Summary of Experimental Conditions and Data from Texas and Louisiana in 1975. Unpublished study. 12 p.

42464201 McGaughey, R. ( 1992) Determination of the Magnitude of Residues of Sodium Chlorate in Potatoes Treated with DEFOL6: Final Report: Lab Project Number: DREX 9002: 9006 010X: 04 9012. Unpublished study prepared by Compliance Services Intl. 112 p.

42930601 McGaughey, R. ( 1993) Determination of the Magnitude of Residues of Sodium Chlorate in Potatoes Treated with DEFOL 6: Lab Project Number: DREX 9002. Unpublished study prepared by Minnesota Valley Testing Labs. 22 p.

Study Citations Considered Supplemental Sources of Information 5620 United States Borax & Chemical Corporation ( 1967) Residue Data. ( Unpublished study received Apr 1, 1969 under 9F0783; CDL: 091347 A)

48007 Abernathy, J.; Miller, C. S.; Richard, J. ( 1975) Sodium chlorate on Sunflowers. Prepared in cooperation with Texas A & M Univ., Agricultural Experiment Station and Iowa State Univ., Ames Laboratory. Unpublished study; 17 p.

48009 Smith, D. T.; Eastin, E. F.; Wiese, A. F.; et al. ( 1976) Summary of Experimental Conditions and Data from Texas and Oklahoma in 1975. ( Unpublished study received Aug 12, 1980 under 2342 964; prepared in cooperation with Texas A & M Univ., Agricultural Experiment Station and others, submitted by Kerr McGee Chemical Corp., Oklahoma City, Okla.; CDL: 243078 I)

48064 Abernathy, J.; Scrib, J.; Miller, C. S.; et al. ( 1975) Sodium chlorate on Sunflowers: Summary of Experimental Conditions and Data from Texas in 1975; prepared in cooperation with Texas A & M Univ. Agricultural Experiment Station and Iowa State Univ., Ames Laboratory E. R. D. A. Unpublished study; 17 p.

48065 Smith, D. T.; Eastin, E. F.; Wiese, A. F.; et al. ( 1975) Summary of Experimental Conditions and Data from Texas and Oklahoma in 1975. ( Unpublished study received Aug 12, 1980 under 2342 964; prepared in cooperation with Texas A & M Univ., Agricultural Ex periment Station and others, submitted by Kerr McGee Chemical Corp., Oklahoma City, Okla.; CDL: 243079 E)

49609 Chipman Chemical Company, Incorporated ( 1962) Progress Report: Residue Data following the Field Use of Shed a Leaf on Tomatoes as a Defoliant/ Desiccant in California and New York State from Applications Made Fall of 1961. ( Unpublished study received Jan 4, 1962 under 359 400; submitted by Rhone Poulenc Chemical Co., Monmouth Junction, N. J.; CDL: 119511 A) Page 119 of 141 53626 Chipman Chemical Company, Incorporated ( 1961) Residue Data Sheet. ( Unpublished study received Jan 4, 1962 under 359 400; submitted by Rhone Poulenc Chemical Co., Monmouth Junction, N. J.; CDL: 119510 A)

58490 Pennwalt Corporation ( 1975) Efficacy of Sodium chlorate Rice. ( Reports by various sources; unpublished study, including published data, received Oct 14, 1976 under 4581 328; CDL: 232133 T)

66803 Walaski, L. J. ( 1960) Residue Analysis and Reports. ( Unpublished study received May 30, 1970 under 0F0926; prepared by Chipman Chemical Co., Inc., submitted by Fenrich Vincent Associates, Manhasset, N. Y.; CDL: 091580 N)

74958 Rhone Poulenc Chemical Company ( 1964) Tests with Shed a leaf L. ( Compilation; unpublished study received Apr 16, 1964 under 359 399; CDL: 023331 A)

74967 Walaski, L. J. ( 1962) Analyses of Dry Edible Beans, Stalks, and Pods for Possible Residues of Borate and Chlorate: BB/ 9/ 62. ( Unpublished study received Dec 3, 1962 under 359 399; prepared by Chipman Chemical Co., Inc., submitted by Rhone Poulenc Chemical Co., Monmouth Junction, N. J.; CDL: 101365 B)

75021 Chipman Chemical Company, Incorporated ( 1960) Results of Analyses for Chlorate and Borate Residues on Cottonseed from 1959 & 1960 California Cotton Samples. ( Unpublished study received Jan 19, 1961 under 359 399; submitted by Rhone Poulenc Chemical Co., Monmouth Junction, N. J.; CDL: 119545 A)

75023 Rhone Poulenc Chemical Company ( 1963) Residues in Sorghum and Rice. ( Compilation; unpublished study, including letter dated Jul 1, 1963 from L. R. Reed to Commissioner of Food & Drugs, Food & Drug Administration, Department of Health, Education, & Wel fare, received Jul 2, 1963 under unknown admin. no.; CDL: 119636 A)

75025 Walaski, L. J. ( 1963) Analysis of Potatoes for Possible Residues of Borate following Applications of Chlorate/ Sodium Metaborate Combinations for Vinekilling: BB/ 1/ 63. ( Unpublished study received May 21, 1963 under 359 399; prepared by Chipman Chemical Co., Inc., submitted by Chipman Chemical Co., Bound Brook, NJ; CDL: 119640 A)

123745 Interregional Research Project No. 4 ( 1973) The Results of Tests on the Amount of Sodium Chlorate Residue Remaining on or in Grain Sorghum, Including a Description of the Analytical Method Used. ( Compilation; unpublished study received Apr 13, 1973 under 3E1386; CDL: 093698 C) Page 120 of 141 140109 Interregional Research Project No. 4 ( 1975) The Results of Tests on the Amount of Sodium Chlorate Residue Remaining in or on Sunflower Seeds, Including a Description of the Analytical Method Used. ( Compilation; unpublished study received Jul 1, 1976 under 6E1825; CDL: 095932 A)

140483 Interregional Research Project No. 4 ( 1977) The Results of Tests on the Amount of Sodium Chlorate Residue Remaining in or on Corn Including a Description of the Analytical Method Used. ( Compilation; unpublished study received Jun 24, 1977 under 7E1972; CDL: 097261 A)

140486 Interregional Research Project No. 4 ( 1976) The Results of Tests on the Amount of Sodium Chlorate Residue Remaining on or in Rice and Rice Straw Including a Description of the Analytical Method Used. ( Compilation; unpublished study received Apr 6, 1976 under 6E1996; CDL: 097358 A)

159211 Ladd, R. ( 1976) Meat and Milk Residue Study with Antor Herbicide in a Dairy Cow [ Dosing Information Only]: Project No. 76 12: IBT No. 8580 09096. Unpublished study prepared by Industrial Bio Test Laboratories, Inc. 21 p. Page 121 of 141 APPENDIX D TOLERANCE REASSESSMENT SUMMARY For Inorganic Chlorates as active or inert ingredients in conventional ( agricultural) pesticides NOTE: Tolerances and/ or exemptions from the requirement of a tolerance for inorganic chlorates as active or inert ingredients in antimicrobial agents is not the purview of HED and should be addressed by AD.

Existing exemptions from the requirement of a tolerance for sodium chlorate ( 073301) as an active ingredient in conventional ( agricultural) pesticides listed under 40 CFR 180.1020 Sodium chlorate is currently registered for preharvest and foliar applications as a defoliant or desiccant to the following food/ feed crops: dry beans, corn, cotton, flax, guar, chili peppers, potatoes, rice, safflower, sorghum ( grain), southern peas ( i. e., cowpeas), soybeans, and sunflowers.

Under 40 CFR 180.1020 ( a) Sodium chlorate is exempt from the requirement of a tolerance for residues in or on the following raw agricultural commodities when used as a defoliant, desiccant, or fungicide in accordance with good agricultural practice: beans ( dry, edible), corn ( fodder), corn ( forage), corn ( grain), cottonseed, flaxseed, flax ( straw), guar beans, peas ( southern), peppers ( chili), potatoes, rice, rice ( straw), safflower ( grain), sorghum ( grain), sorghum ( fodder), sorghum ( forage), soybeans and sunflower seed.

Under 40 CFR 180.1020 ( b) A time limited exemption from the requirement of a tolerance is established for residues of the defoliant/ desiccant in connection with use of the pesticide under section 18 emergency exemptions granted by EPA. This exemption has been granted for wheat and will expire on 12/ 31/ 04. As requested by the Registration Division ( Sodium Chlorate Use Closure Memo Amendment; J. Guerry; dated 11/ 15/ 2004) the use of sodium chlorate on wheat is also addressed herein with the intention to convert the time limited exemption status to a permanent exemption from the requirement of a tolerance under 40 CFR. 1020 ( a). The proposed use rate is for a single application of sodium chlorate to wheat at 6 lbs ai/ A with a 3 day PHI.

Sodium chlorate exemptions under 40 CFR 180.1020 ( a) from the requirement of a tolerance should be amended as follows to: ( 1) specify defoliant and desiccant use only, ( 2) specify use on crops rather than raw agricultural commodities, ( 3) include wheat concomitant with the revocation of wheat under 40 CFR 180.1020 ( b).

40 CFR 180.1020 ( a) Sodium chlorate is exempt from the requirement of a tolerance for residues when used as a defoliant or desiccant in accordance with good agricultural practice on the following crops: Bean ( dry), Corn, Cotton, Cowpeas, Flax, Guar, Pepper ( non bell), Potato, Rice, Safflower, Sorghum ( grain), Soybeans, Sunflower, and Wheat. Page 122 of 141 Table D. 1. Tolerance Reassessment Summary for Sodium Chlorate Listed under 40 CFR 180.1020( a)

Commodity Current Tolerance ( ppm) Tolerance Reassessment ( ppm) [ Correct Definition] Comments beans, dry, edible Exempt Exempt [ Bean ( dry)]

corn, fodder Exempt Exempt [ Corn]

corn, forage Exempt corn, grain Exempt cottonseed Exempt Exempt [ Cotton]

flaxseed Exempt Exempt [ Flax]

flax, straw Exempt Revoke Flax straw is not listed in Table 1 of OPPTS 860.1000 guar beans Exempt Exempt [ Guar]

peas, southern Exempt Exempt [ Cowpea]

potatoes Exempt Exempt [ Potato]

peppers, chili Exempt Exempt [ Pepper ( nonbell)]

rice Exempt Exempt [ Rice]

rice, straw Exempt Exempt safflower, grain Exempt Exempt [ Safflower]

sorghum, grain Exempt Exempt [ Sorghum ( grain)]

sorghum, fodder Exempt sorghum, forage Exempt soybeans Exempt Exempt [ Soybeans]

sunflower seed Exempt Exempt [ Sunflower]

Wheat None Exempt [ Wheat] Concomitant with the revocation of wheat under 40 CFR 180.1020 ( b) Page 123 of 141 Needed exemptions from the requirement of a tolerance for sodium chlorate ( 873301) and potassium chlorate ( 900583) as inert ingredients in conventional pesticides Sodium chlorate ( 873301) as an inert ingredient in herbicide formulation products can be applied professionally to agricultural ( corn, guava, macadamia nuts, sorghum grain, sugarcane, wheat), commercial ( non agricultural), and residential sites. These conventional pesticide products contain < 1 % sodium chlorate and can be applied at rates no greater than 0.07 lb ( as sodium chlorate) per acre.

Potassium chlorate ( 900583) as an inert ingredient in airborne fungicide products can be applied in poultry premises. These conventional pesticide products contain < 20% potassium chlorate and can be applied at rates not greater than 0.01 lb ( as potassium chlorate) per 500 ft3.

Table D. 2. Tolerance Exemption Needed Tolerance Exemption Expression PC Code CAS Reg No. 40 CFR § Use ( Pesticidal) List Classification Sodium chlorate 873301 7775 09 9 180.920 1 Stabilizer 3 Potassium chlorate 900583 3811 04 9 180.930 2 Oxidizer 3 1 Residues listed in 40 CFR § 180.920 [ formerly 40 CFR § 180.100( d)] are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert ( or occasionally active) ingredients in pesticide formulations applied to growing crops only. 2 Residues listed in 40 CFR § 180.930 [ formerly 40 CFR § 180.100( e)] are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert ( or occasionally active) ingredients in pesticide formulations applied to animals.

Codex/ International Harmonization There are no Codex maximum residue limits ( MRLs) for sodium chlorate; therefore, no questions of compatibility with U. S. tolerances exist. Page 124 of 141 APPENDIX E CHLORATE ( ClO3 b ) DIETARY EXPOSURE ESTIMATES in FOOD Exposure estimates for chlorate residues in food are considered conservative and the dietary ( food only) risk assessments are deemed upper bound estimates.

Dietary exposure ( food only) to inorganic chlorates as the chlorate ion ( ClO 3 b ) may be expected from the following dietary exposure routes: ( 1) from sodium chlorate ( 073301) as an active ingredient in conventional ( agricultural) pesticides used on food crops; ( 2) from sodium chlorate ( 873301) and potassium chlorate ( 900583) as inert ingredients in conventional pesticides used on food crops or in poultry premises; ( 3) from secondary residues in meat/ milk/ poultry/ eggs due to residues in animal feedstuffs; ( 4) from sodium chlorate ( 873301) and calcium chlorate ( 875606) as inert ingredients in antimicrobial agents used as fruit, vegetable, and egg sanitizing washes, on mushrooms to control bacterial blotch, as treatments to seed used for sprouting, for conditioning live oysters, in poultry drinking water, in fish filleting, and in pecan cracking/ dyeing; ( 5) as a potential redox of chlorine dioxide and sodium chlorite in conventional and antimicrobial pesticides; ( 6) from degradation of hypochlorites in antimicrobial agents used as fruit and vegetable washes; and, ( 7) from translocation of very small amounts of chlorate ion ( ClO 3 b ) by plants ( translocation of significant amounts would be phytotoxic to plants) from the environment which may be present as a result of inorganic chlorate pesticide uses. These dietary ( food) routes of exposure are discussed below. Dietary exposure estimates for food only to be incorporated into the dietary risk assessments for inorganic chlorate are summarized in Table E. 1 below.

No food monitoring data are available for this risk assessment; only limited, chemical specific field trial data are available. Exposure estimates in food were based on field trial data or, in the case of fruit/ vegetable/ other washes, was derived from a film thickness model. No Chemical specific livestock metabolism or feeding data are available; exposure estimates in meat, milk, poultry, and eggs were derived from rat metabolism data, field trial data, and livestock reference information concerning feed consumption, tissue weights, and milk production. In some cases, due to raw data limitations, food exposure estimates are calculated as sodium chlorate. The effects of washing after foliar treatments and, in some cases such as meat, milk, poultry and eggs estimates, percent crop treated data were also incorporated into these exposure estimates. Page 125 of 141 Table E. 1. Summary of Chlorate Dietary ( Food) Exposure Estimates for the Dietary Risk Assessments Food Group Food Crop Acute Dietary Screen  Do Not Use % Crop Treated Data in DEEM Chronic Dietary Comments From Agricultural Uses Only From All Uses Exposure Estimate ( ppm) Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Vegetables chili peppers 0.5 0.5 / 0.2 Maximum/ Average Exposure Estimate from agricultural use: Based on chili pepper, potato, and cereal grain field trial data and considering the effects of washing field treated RACs as demonstrated by the chili pepper washing data, residues are expected to be < 1 ppm; the exposure estimate is 0.5 ppm. Note:

Incorporating available sodium chlorate percent crop treated data would result in an estimated residue level below that from sanitizing fruit and vegetable wash.

Maximum/ Average Exposure Estimate from sanitizing fruit and vegetable wash: Estimate derived from film thickness model developed by FDA for sanitizing non porous surfaces. Residues are expected to be < 0.3 ppm; the exposure estimate is 0.2 ppm.

potatoes 0.5 0.5 / 0.2 sweet corn 0.5 0.5 / 0.2 dry beans,

guar beans,

southern peas,

soybeans 0.5 0.5 / 0.2 Maximum/ Average Exposure Estimate from agricultural use: Based on seed/ bean field trial data taken as a whole, residues are expected to be < 1 ppm; the exposure estimate is 0.5 ppm. Note: Incorporating available sodium chlorate percent crop treated data would result in an estimated residue level below that from sanitizing fruit and vegetable wash.

Maximum/ Average Exposure Estimate from sanitizing fruit and vegetable wash: Estimate derived from film thickness model developed by FDA for sanitizing non porous surfaces. Residues are expected to be < 0.3 ppm; the exposure estimate is 0.2 ppm.

all others 0.2 N/ A N/ A 0.2 Maximum/ Average Exposure Estimate from sanitizing fruit and vegetable wash: Estimate derived from film thickness model developed by FDA for sanitizing non porous surfaces. Residues are expected to be < 0.3 ppm; the exposure estimate is 0.2 ppm. Food Group Food Crop Acute Dietary Screen  Do Not Use % Crop Treated Data in DEEM Chronic Dietary Comments From Agricultural Uses Only From All Uses Exposure Estimate ( ppm) Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Page 126 of 141 Fruits guava 0.5 0.5 0.5 Maximum/ Average Exposure Estimate from agricultural use: Based on the exposure estimates for sodium chlorate, as an active ingredient, in conventional ( agricultural) pesticides used on food crops and considering the effects of washing field treated RACs as demonstrated by the chili pepper washing data, residues are expected to be < 1 ppm; the exposure estimate is 0.5 ppm. Note: No percent crop treated data are currently available.

Maximum/ Average Exposure Estimate from sanitizing fruit and vegetable wash: Estimate derived from film thickness model developed by FDA for sanitizing non porous surfaces. Residues are expected to be < 0.3 ppm; the exposure estimate is 0.2 ppm.

citrus fruits ( except peels),

bananas, plantains, and coconuts zero N/ A N/ A zero Maximum/ Average Exposure Estimate from sanitizing fruit and vegetable wash: Estimate derived from film thickness model developed by FDA for sanitizing non porous surfaces. Residues are expected to be < 0.3 ppm; the exposure estimate is 0.2 ppm. For citrus fruits, bananas/ plantains, and coconuts which have substantial outer peels/ husks which are removed prior to consumption and processing,

residues are expected to be essentially nil; the exposure estimate is zero. Residues in citrus fruit peels are estimated at 0.2 ppm.

citrus fruit peel 0.2 0.2 all others 0.2 0.2 Seeds cottonseed,

flaxseed, safflower seed, sunflower seed 0.5 0.5 / 0.5 / Maximum/ Average Exposure Estimate from agricultural use: Based on seed/ bean field trial data taken as a whole, residues are expected to be < 1 ppm; the exposure estimate is 0.5 ppm. Food Group Food Crop Acute Dietary Screen  Do Not Use % Crop Treated Data in DEEM Chronic Dietary Comments From Agricultural Uses Only From All Uses Exposure Estimate ( ppm) Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Page 127 of 141 Cereal grains rice 0.5 0.5 / 0.5 / Maximum/ Average Exposure Estimate from agricultural use: Based on rice field trial demonstrating residues in/ on rice w/ out outer hulls, residues are expected to be < 1 ppm; the exposure estimate is 0.5 ppm.

wheat 0.5 0.5 / 0.5 / Maximum/ Average Exposure Estimate from agricultural use: Based on wheat and other cereal grain field trial data, residues are expected to be < 1 ppm; the exposure estimate is 0.5 ppm.

corn ( except sweet) 20 10 / 10 / Maximum/ Average Exposure Estimate from agricultural use: Translated from sorghum field trial data,

maximum and average residues in/ on corn grain are not expected to exceed 20 ppm and 10 ppm,

respectively, at the point of harvest ( 14 day PHI).

sorghum 70 40 / 40 / Maximum/ Average Exposure Estimate from agricultural use: Based on sorghum field trial data,

maximum and average residues in/ on sorghum grain are not expected to exceed 70 ppm and 40 ppm,

respectively, at the point of harvest ( 7 day PHI).

Nuts Macadamia Nuts 0.5 0.5 0.5 Maximum/ Average Exposure Estimate from agricultural use: Based on the exposure estimates for sodium chlorate, as an active ingredient, in conventional ( agricultural) pesticides used on food crops,

residues are expected to be < 1 ppm; the exposure estimate is 0.5 ppm. Note: No percent crop treated data are currently available.

Pecans 0.2 N/ A N/ A 0.2 Maximum/ Average Exposure Estimate from pecan cracking and dyeing: Estimate derived from film thickness model developed by FDA for sanitizing non porous surfaces. Residues are expected to be < 0.3 ppm; the exposure estimate is 0.2 ppm. Food Group Food Crop Acute Dietary Screen  Do Not Use % Crop Treated Data in DEEM Chronic Dietary Comments From Agricultural Uses Only From All Uses Exposure Estimate ( ppm) Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Page 128 of 141 Animal Tissues Meat, Poultry,

and Eggs 10 0.1 0.1 Maximum/ Average Exposure Estimates from Agricultural uses: Conservative estimates based on the rat metabolism data that demonstrated that < 1% of a single initial dose of chlorate is expected to be incurred in any animal tissue 72 hours after oral exposure.

Maximum residues are expected to be < 12 ppm; the maximum exposure estimate is 10 ppm and is based on:

° Maximum theoretical dietary burden for livestock ( 500 ppm)

° Maximum feed rate for livestock ( 9.1 kg/ day)

° Average weight ( 4 kg) of the smallest ( by weight) organ of interest ( kidney)

° Percent crop treated data is not incorporated into the estimate Average residues are expected to be < 0.2 ppm; the average exposure estimate is 0.1 ppm and is based on:

° Highest average theoretical dietary burden for livestock ( 175 ppm)

° Maximum feed rate for livestock ( 9.1 kg/ day)

° Average weight ( 4 kg) of the smallest ( by weight) organ of interest ( kidney)

° Incorporates highest percent crop treated data ( cotton 5%) into the estimate Maximum/ Average Exposure Estimates from sanitizing washes: Covered by estimates from agricultural uses. Food Group Food Crop Acute Dietary Screen  Do Not Use % Crop Treated Data in DEEM Chronic Dietary Comments From Agricultural Uses Only From All Uses Exposure Estimate ( ppm) Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Page 129 of 141 Milk 1 0.01 0.01 Maximum/ Average Exposure Estimates from Agricultural uses: Conservative estimates based on the rat metabolism data that demonstrated that < 1% of a single initial dose of chlorate is expected to be incurred in any animal tissue 72 hours after oral exposure.

Maximum residues are expected to be < 2 ppm; the maximum exposure estimate is 1 ppm and is based on:

° Maximum theoretical dietary burden for cattle( 500 ppm)

° Maximum feed rate for cattle ( 9.1 kg/ day)

° Average milk production per day ( ca. 30 kg)

° Percent crop treated data are not incorporated into the estimate Average residues are expected to be < 0.03 ppm; the average exposure estimate is 0.01 ppm and is based on:

° Highest average theoretical dietary burden for cattle ( 175 ppm)

° Maximum feed rate for ( 9.1 kg/ day)

° Average milk production per day ( ca. 30 kg)

° Incorporates highest percent crop treated data ( cotton 5%) into the estimate Food Group Food Crop Acute Dietary Screen  Do Not Use % Crop Treated Data in DEEM Chronic Dietary Comments From Agricultural Uses Only From All Uses Exposure Estimate ( ppm) Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Exposure Estimate ( ppm) / = Use % Crop Treated Data in DEEM Page 130 of 141 Misc. Fish fillets 0.2 N/ A N/ A 0.2 Maximum/ Average Exposure Estimate from sanitizing fish fillet wash: Estimate derived from film thickness model developed by FDA for sanitizing non porous surfaces. Residues are expected to be < 0.3 ppm; the exposure estimate is 0.2 ppm.

Oysters 0.2 N/ A N/ A 0.2 Maximum/ Average Exposure Estimate from conditioning live oysters: Estimate derived from film thickness model developed by FDA for sanitizing non porous surfaces. Residues are expected to be < 0.3 ppm; the exposure estimate is 0.2 ppm.

Mushrooms 0.2 N/ A N/ A 0.2 Maximum/ Average Exposure Estimate from use to control bacterial blotch on mushrooms: Estimate derived from film thickness model developed by FDA for sanitizing non porous surfaces. Residues are expected to be < 0.3 ppm; the exposure estimate is 0.2 ppm.

Sugarcane 0.5 0.5 0.5 Maximum/ Average Exposure Estimate from agricultural use: Based on exposure estimates from sodium chlorate, as an active ingredient, in conventional ( agricultural) pesticides used on food crops.

Residues are expected to be < 1 ppm; the exposure estimate is 0.5 ppm. Note: No percent crop treated data are currently available.

Note: According to the Usage Report in Support of Reregistration for Sodium Chlorate ( Chemical Code 073301/ Case No. 4049) dated 10/ 27/ 2004, the highest average Percent Crop Treated ( PCT) for any crop reported is 5% PCT for cotton; all others are reported as < 1% PCT except processed lima beans and safflower which are reported as 2% PCT. Page 131 of 141 Dietary Exposure Route 1. Chlorate ( ClO 3 b ) dietary exposure estimates from sodium chlorate ( 073301) as an active ingredient in conventional ( agricultural) pesticides used on food crops Sodium chlorate is currently registered for preharvest and foliar applications as a defoliant or desiccant to the following food/ feed crops: dry beans, corn, cotton, flax, guar, chili peppers, potatoes, rice, safflower, sorghum ( grain), southern peas ( i. e., cowpeas), soybeans, and sunflowers. For food/ feed uses, sodium chlorate is formulated as a soluble concentrate ( SC) with the active ingredient ranging from 18% to 47.2%. Sodium chlorate may be applied using aircraft or ground spray equipment, including high and low volume equipment.

Uses of sodium chlorate as a defoliant or desiccant on cauliflower, cucurbit vegetables, and okra grown for seed only are considered non food uses. Uses of sodium chlorate on ornamental gourds and fallow lands are also considered non food uses. These non food uses will not be discussed further with regards to dietary exposure/ risk considerations.

Under 40 CFR 180.1020 ( a) Sodium chlorate is exempt from the requirement of a tolerance for residues in or on the following raw agricultural commodities when used as a defoliant, desiccant, or fungicide in accordance with good agricultural practice: beans ( dry, edible), corn ( fodder), corn ( forage), corn ( grain), cottonseed, flaxseed, flax ( straw), guar beans, peas ( southern), peppers ( chili), potatoes, rice, rice ( straw), safflower ( grain), sorghum ( grain), sorghum ( fodder), sorghum ( forage), soybeans and sunflower seed.

Under 40 CFR 180.1020 ( b) A time limited exemption from the requirement of a tolerance is established for residues of the defoliant/ desiccant in connection with use of the pesticide under section 18 emergency exemptions granted by EPA. This exemption has been granted for wheat and will expire on 12/ 31/ 04. As requested by the Registration Division ( Sodium Chlorate Use Closure Memo Amendment; J. Guerry; dated 11/ 15/ 2004) the use of sodium chlorate on wheat is also addressed herein with the intention to convert the time limited exemption status to a permanent exemption from the requirement of a tolerance under 40 CFR. 1020 ( a). The proposed use rate is for a single application of sodium chlorate to wheat at 6 lbs ai/ A with a 3 day PHI.

Based on the available flax, guar, southern pea, soybean, and sunflower field trial data no detectable residues of sodium chlorate (< 1 ppm) are expected in/ on dry beans, guar beans, southern peas, soybeans, flaxseed, safflower seed, and sunflower seed at the point of harvest from the maximum use rate of sodium chlorate on dry beans, guar, southern peas, soybeans, flax, safflower, and sunflower ( 1 application; 7.5 lbs ai/ A; 7 day PHI). Furthermore, no detectable residues of sodium chlorate (< 1 ppm) are expected in/ on cottonseed at the point of harvest from the maximum use rate of sodium chlorate on cotton ( 2 applications, 7.5 lbs ai/ A/ application; 7 day PHI). Any residues which might be detected at the point of harvest are expected to be primarily surface residues which would be substantially removed prior to the point of consumption.

Based on the available chili pepper field trial data, it is possible that detectable residues of sodium chlorate ( ca. 13 ppm) might be found on the surface of unwashed chili peppers treated with Page 132 of 141 sodium chlorate at the maximum use rate of sodium chlorate on chili peppers ( 1 application; 12.5 lbs ai/ A/ application; 10 day PHI). However, these residues are primarily surface residues present at the point of harvest which would be substantially removed by washing (< 1 ppm) prior to the point of consumption.

Based on the available potato field trial data, no detectable residue of sodium chlorate (< 1 ppm) are expected in/ on potato tubers at the point of harvest from the maximum use rate of sodium chlorate on potatoes ( 1 application; 12.5 lbs ai/ A; 7 day PHI). As demonstrated by the chili pepper field trial data, any residues present at harvest are expected to be primarily surface residues which would be substantially removed by washing prior to the point of consumption.

Based on the available oat, rice, sorghum, and wheat field trial data, it is possible that detectable residues of sodium chlorate ( ca. 70 ppm as demonstrated by sorghum grain) might be found on the surface of cereal grains retaining their outer hulls at harvest ( such as oats and sorghum) from the maximum use rate of sodium chlorate on rice and sorghum ( 1 application; 7.5 lbs ai/ A; 7 day PHI) and wheat ( 1 application; 6 lbs ai/ A; 3 day PHI). However, once the outer hulls are removed ( either at harvest or during processing), no detectable residues of sodium chlorate (< 1 ppm) are expected in/ on cereal grains such as rice and wheat ( as demonstrated by rice w/ out hulls and wheat grain data).

Based on the available sorghum field trial data alone, maximum residues in/ on sorghum grain harvested 7 14 days after treatment with sodium chlorate at the maximum use rate for sorghum ( 1 application; 7.5 lbs ai/ A; 7 day PHI) are not expected to exceed 70 ppm. On average, residues in/ on sorghum grain harvested 7 14 days after treatment with sodium chlorate at the maximum use rate on sorghum ( 1 application; 7.5 lbs ai/ A; 7 day PHI) are not expected to exceed 40 ppm.

Translating the available sorghum field trial data to corn, residues of sodium chlorate are not expected to exceed 20 ppm ( ca. 10 ppm on average) in/ on corn grain at the point of harvest from the maximum use rate of sodium chlorate on corn ( 1 application, 7.5 lbs ai/ A; 14 day PHI). As demonstrated by the chili pepper field trial data, any residues present at harvest are expected to be primarily surface residues which would be substantially removed by washing prior to the point of consumption. Hence, residues of sodium chlorate in/ on sweet corn after washing and prior to consumption would not be expected to exceed 1 ppm.

Based on the available straw ( flax, oat, wheat, rice) and forage ( guar plants, sorghum stalks, soybean forage) data, maximum residues of sodium chlorate in/ on straw and forage livestock feedstuffs harvested 3 7 days after treatment with sodium chlorate at the maximum use rate permitted on forage crops ( 1 or 2 applications; 7.5 lbs ai/ A/ application) are not expected to exceed 300 ppm at the point of harvest. On average, residues in/ on straw and forage livestock feedstuffs should not exceed 100 ppm when harvested 7 14 days after foliar treatment with sodium chlorate at the maximum use rate permitted on forage crops ( 1 or 2 applications; 7.5 lbs ai/ A/ application). Page 133 of 141 Dietary Exposure Route 2. Chlorate ( ClO 3 b ) dietary exposure estimates from sodium chlorate ( 873301) and potassium chlorate ( 900583) as inert ingredients in conventional ( agricultural) pesticides used on food crops or in poultry premises Sodium chlorate ( 873301) as an inert ingredient in herbicide formulation products can be applied professionally to agricultural ( corn, guava, macadamia nuts, sorghum grain, sugarcane, wheat), commercial ( non agricultural), and residential sites. These conventional pesticide products contain < 1 % sodium chlorate and can be applied at rates no greater than 0.07 lb ( as sodium chlorate) per acre.

Taking into account the small percentage of sodium chlorate ( 873301) in the product( s) and the application rate( s) of the product( s) at issue, chlorate dietary exposure estimates in/ on corn, guava, macadamia nuts, sorghum grain, sugarcane, and wheat are expected to be < 1 ppm based on the exposure estimates for sodium chlorate ( 073301) as an active ingredient used in conventional ( agricultural) pesticides which are used at higher rates ( 6 12.5 lb ai/ A).

Specifically, based on the available chili pepper and potato data, residues of chlorate in/ on guava, macadamia nuts, and sugarcane are expected to be primarily surface residues leaving < 1 ppm in/ on these commodities after washing and/ or removal of outer surfaces prior to consumption, as demonstrated by the available chili pepper washing data and the rice with and w/ out hulls field trial data.

Potassium chlorate ( 900583) as an inert ingredient in airborne fungicide products can be applied in poultry premises. These conventional pesticide products contain < 20% potassium chlorate and can be applied at rates not greater than 0.01 lb ( as potassium chlorate) per 500 ft3.

No chlorate residues are expected in egg commodities from the use of potassium chlorate ( 900583) as an inert ingredient in poultry premises. Page 134 of 141 Dietary Exposure Route 3. Chlorate ( ClO 3 b ) dietary exposure estimates from secondary residues incurred in meat, milk, poultry and eggs from consumption of feedstuffs treated with sodium chlorate ( 073301 or 873301) as an active or inert ingredient in conventional ( agricultural) pesticides The maximum residues ( excluding percent crop treated data) in meat, poultry, and eggs are estimated at 10 ppm and in milk is estimated at 1 ppm based on the following information and assumptions:

° The maximum theoretical dietary burden for livestock is 500 ppm for cattle feed on a dry wt. basis ° Cattle eat a maximum of 9.1 kg of feed per day on a dry wt. basis ( Update of Livestock Feed Consumption, 1993); hence, the highest average theoretical dietary exposure for sodium chlorate to livestock is 4600 mg per day ° Based on the available rat metabolism data, < 1% of the initial dose of chlorate is expected to be incurred in animal tissues 72 hours after exposure ( Abdel Rahman et al, 1982, 1984b and 1985); hence < 46 mg is expected to be incurred in any livestock tissue of interest ° Assuming that kidneys have the lowest weight of the organs/ tissues of interest ( other than milk) in livestock ( i. e., compared to meat, liver, fat, and eggs) ° Assuming that the average weight of cattle kidneys is about 4 kg ( Update of Livestock Feed Consumption, 1993; cattle kidneys weigh 3.6 4.5 kg) ° Assuming that the average milk production per day is about 30 kg ( Frank, 2002; milk production is 50 90 lb milk/ cow/ day)

Calculations:

( Maximum Theoretical Dietary Exposure ( 4600 mg) x Percent of Dietary Exposure Expected in Organs (< 1%) Average Weight of the Organ/ Tissue of Interest ( Kidney at 4 Kg or Milk at 30 Kg)

Maximum Residue Estimate in Meat, Poultry, and Eggs = < 12 ppm; estimated at 10 ppm Maximum Residue Estimate in Milk = < 2 ppm; estimated at 1 ppm The highest average residues ( including percent crop treated data) in meat, poultry, and eggs are estimated at 0.1 ppm and in milk is estimated at 0.01 ppm based on the following information and assumptions:

° The highest average theoretical dietary burden for livestock is 175 ppm for cattle feed on a dry wt. basis ( excluding percent crop treated data) ° Cattle eat a maximum of 9.1 kg of feed per day on a dry wt. basis ( Update of Livestock Feed Consumption, 1993); hence, the highest average theoretical dietary exposure for sodium chlorate to livestock is 1600 mg per day ( excluding percent crop treated data) ° The maximum percent crop treated is 5% on cotton all other feed crops are < 1% ( Usage Report from A. Halvorson to B. Cropp Kohlligian and J. Guerry dated 10/ 27/ 2004) Page 135 of 141 hence, the highest average theoretical dietary exposure for sodium chlorate to livestock is 80 mg per day ( including percent crop treated data at 5%). ° Based on the available rat metabolism data, < 1% of the initial dose of chlorate is expected to be incurred in animal tissues 72 hours after exposure ( Abdel Rahman et al, 1982, 1984b and 1985); hence < 0.8 mg is expected to be incurred in any livestock tissue of interest ° Assuming that kidneys have the lowest weight of the organs/ tissues of interest ( other than milk) in livestock ( i. e., compared to meat, liver, fat, and eggs) ° Assuming that the average weight of cattle kidneys is about 4 kg ( Update of Livestock Feed Consumption, 1993; cattle kidneys weigh 3.6 4.5 kg) ° Assuming that the average milk production per day is about 30 kg ( Frank, 2002; milk production is 50 90 lb milk/ cow/ day)

Calculations:

( Highest Average Theoretical Dietary Exposure ( 80 mg) x Percent of Dietary Exposure Expected in Organs (< 1%) Average Weight of the Organ/ Tissue of Interest ( Kidney at 4 Kg or Milk at 30 Kg)

Highest Average Residue Estimate in Meat, Poultry, and Eggs = < 0.2 ppm; estimated at 0.1 ppm Highest Average Residue Estimate in Milk = < 0.03 ppm; estimated at 0.01 ppm Page 136 of 141 Dietary Exposure Route 4. Chlorate ( ClO 3 b ) dietary exposure estimates from sodium chlorate ( 873301) and calcium chlorate ( 875606) as inert ingredients in antimicrobial agents used: ( 1) as fruit, vegetable, and egg sanitizing washes; ( 2) to control bacterial blotch on mushrooms; ( 3) as treatment to seed used for sprouting; ( 4) for conditioning live oysters; ( 5) in poultry drinking water; ( 6) in fish filleting; and ( 7) pecan cracking/ dyeing Fruit and vegetable sanitizing washes: Using a film thickness model, residues of chlorate in/ on fruits and vegetables treated at the maximum use rate are expected to be < 0.3 ppm; estimated at 0.2 ppm.

This estimate will also be used for seed sprouting, mushrooms, oysters, fish fillets, and pecans.

This estimate will also cover estimates on fruits and vegetables from Dietary Exposure Routes 5, 6, 7, and 8 identified below.

Since these residues are expected to be primarily surface residues in fruits which have substantial outer peels which are removed prior to consumption, residues of chlorate in citrus fruits, bananas and plantains are expected to be essentially nil ( zero) once the peels are removed.

No chlorate residues are expected in egg commodities from surface sanitizing washes. Chlorate residue estimates in poultry commodities from chlorate in antimicrobial agents use in poultry drinking water are covered by the secondary residue estimates for meat/ milk/ poultry/ egg addressed above under Dietary Exposure Route 3.

Calculation for percent chlorate in the sanitizing washes:

For the active ingredient( s) the maximum use rate is 500 ppm as total chlorine in the sanitizing wash water. Exposure time is 1 2 minutes.

Percent of chlorate as an inert in the product is at most 2%. This is equivalent to ca. < 15 ppm or < 0.0015% chlorate in the sanitizing wash water.

Note: The maximum or peak concentration of chlorate ion ( ClO3 b ) in drinking water is estimated at 9 mg/ L and is based on the available AwwaRF ( 1995) survey study report data.

Calculation of the surface and weight of treated fruits and vegetables:

As a model a small fruit with high surface to volume ratio such as a blueberry was selected to represent all fruits and vegetables.

Information Provided by Cassi Walls of AD: Diameter of one blueberry = 20 mm Page 137 of 141 Source: Blueberry Research at the University of Georgia http:// www. ces. uga. edu/ ES pubs/ RR662. htm# CPPU% 20Enhances% 20Fruit% 20Set Surface area of one blueberry = 12.56 cm2 Based on surface area of a sphere where A = 4Br2 ( where r = 10mm = 1cm) A = 4( 3.14)( 1 cm2) = 12.56 cm2 Information Provided by Cassi Walls of AD: Mass of one blueberry = 0.00136 kg ( where 50 berries = 68 g or 0.068 kg) Source: USDA's nutrient database http:// www. nal. usda. gov/ fnic/ foodcomp/ search/

Calculation of chlorate residues on blueberries Information Provided by Cassi Walls of AD: Assumes the film thickness of the sanitizing solution on the surface of the berry is 0.0023 g ( 2.3 mg) sanitizing solution/ cm2 Source: Proctor and Gamble exposure assessment for ingestion of dishwashing product residues  based on the amount of rinse water in contact with dishware surfaces http:// www. scienceinthebox. com/ en_ UK/ safety/ ingestionfromsurface_ en. html 2.3 mg/ cm2 ( film thickness) x 12.56 cm2 ( surface area) x < 0.0015% chlorate in solution 0.00136 kg blueberry Chlorate residues on blueberry = < 0.3 ppm; estimated at 0.2 ppm Page 138 of 141 Dietary Exposure Route 5. Chlorate ( ClO 3 b ) dietary exposure estimates from potential redox of chlorine dioxide as the antimicrobial agent in fruit and vegetable washes and water used in poultry processing These dietary exposure concerns are covered by the estimates from Dietary Exposure Routes 3 and 4 discussed above.

Under 173.300 concerning secondary direct food additives permitted in food for human consumption chlorine dioxide ( CAS Reg. No. 10049 04 4) may be safely used in food in accordance with the following prescribed conditions: ( a) The additive is generated by one of the following methods: Treating an aqueous solution of sodium chlorite with either chlorine gas or a mixture of sodium hypochlorite and hydrochloric acid, or treating an aqueous solution of sodium chlorate with hydrogen peroxide in the presence of sulfuric acid. In either case, the generator effluent contains at least 90 percent ( by weight) of chlorine dioxide with respect to all chlorine species as determined by Method 4500 ClO2 E in the    Standard Methods for the Examination of Water and Wastewater,'' 18th ed., 1992, or an equivalent method. Method 4500 ClO2 E is incorporated by reference in accordance with 5 U. S. C. 552( a) and 1 CFR part 51. The additive may be used as an antimicrobial agent in water used in poultry processing in an amount not to exceed 3 parts per million ( ppm) residual chlorine dioxide as determined by Method 4500 ClO2 E, referenced in paragraph ( a) of this section, or an equivalent method. ( 2) The additive may be used as an antimicrobial agent in water used to wash fruits and vegetables that are not raw agricultural commodities in an amount not to exceed 3 ppm residual chlorine dioxide as determined by Method 4500 ClO2 E, referenced in paragraph ( a) of this section, or an equivalent method. Treatment of the fruits and vegetables with chlorine dioxide shall be followed by a potable water rinse or by blanching, cooking, or canning.

Dietary Exposure Route 6. Chlorate ( ClO 3 b ) dietary exposure estimates from degradation of sodium hypochlorite or calcium hypochlorite as antimicrobial agents in fruit and vegetable washes These dietary exposure concerns are covered by the estimates from Dietary Exposure Route 4 discussed above.

Under 40 CFR 180.2 sodium hypochlorite is generally regarded as safe Under 40 CFR 180.1054 ( a) Calcium hypochlorite is exempted from the requirement of a tolerance when used preharvest or postharvest in solution on all raw agricultural commodities. ( b) Calcium hypochlorite is exempted from the requirement of a tolerance in or on grapes when used as a fumigant postharvest by means of a chlorine generator pad.

Under 21 CFR 173.315 concerning secondary direct food additives permitted in food for human consumption, chemicals used in washing or to assist in the lye peeling of fruits and vegetables ... sodium hypochlorite ... The use of the chemicals is followed by rinsing with potable water to remove, to the extent possible, residues of the chemical. Page 139 of 141 Dietary Exposure Route 7. Chlorate ( ClO 3 b ) dietary exposure estimates from potential redox of acidified sodium chlorite as an antimicrobial agent used in fruit and vegetable washes and poultry carcass and red meat processing water These dietary exposure concerns are covered by the estimates from Dietary Exposure Routes 3 and 4 discussed above.

Under 21 CFR 173.325 concerning secondary direct food additives permitted in food for human consumption, acidified sodium chlorite solutions may be safely used in accordance with the following prescribed conditions: ( a) The additive is produced by mixing an aqueous solution of sodium chlorite ( CAS Reg. No. 7758 19 2) with any generally recognized as safe ( GRAS) acid. ( b)( 1) The additive is used as an antimicrobial agent in poultry processing water in accordance with current industry practice under the following conditions: ( i) As a component of a carcass spray or dip solution prior to immersion of the intact carcass in a prechiller or chiller tank; ( ii) In a prechiller or chiller solution for application to the intact carcass; ( iii) As a component of a spray or dip solution for application to poultry carcass parts; ( iv) In a prechiller or chiller solution for application to poultry carcass parts; or ( v) As a component of a post chill carcass spray or dip solution when applied to poultry meat, organs, or related parts or trim. ( 2) When used in a spray or dip solution, the additive is used at levels that result in sodium chlorite concentrations between 500 and 1,200 parts per million ( ppm), in combination with any GRAS acid at a level sufficient to achieve a solution pH of 2.3 to 2.9. ( 3) When used in a prechiller or chiller solution, the additive is used at levels that result in sodium chlorite concentrations between 50 and 150 ppm, in combination with any GRAS acid at levels sufficient to achieve a solution pH of 2.8 to 3.2. ( c) The additive is used as an antimicrobial agent in accordance with current industry practice in the processing of red meat, red meat parts, and organs as a component of a spray or in the processing of red meat parts and organs as a component of a dip. Applied as a dip or spray, the additive is used at levels that result in sodium chlorite concentrations between 500 and 1,200 ppm in combination with any GRAS acid at levels sufficient to achieve a solution pH of 2.5 to 2.9. ( d) The additive is used as an antimicrobial agent in water and ice that are used to rinse, wash, thaw, transport, or store seafood in accordance with current industry standards of good manufacturing practice. The additive is produced by mixing an aqueous solution of sodium chlorite with any GRAS acid to achieve a pH in the range of 2.5 to 2.9 and diluting this solution with water to achieve an actual use concentration of 40 to 50 parts per million ( ppm) sodium chlorite. Any seafood that is intended to be consumed raw shall be subjected to a potable water rinse prior to consumption. ( e) The additive is used as an antimicrobial agent on raw agricultural commodities in the preparing, packing, or holding of the food for commercial purposes, consistent with section 201( q)( 1)( B)( i) of the act, and not applied for use under section 201( q)( 1)( B)( i)( I), ( q)( 1)( B)( i)( II), or ( q)( 1)( B)( i)( III) of the act, in accordance with current industry standards of good manufacturing practice. Applied as a dip or a spray, the additive is used at levels that result in chlorite concentrations of 500 to 1200 parts per million ( ppm), in combination with any GRAS acid at levels sufficient to achieve a pH of 2.3 to 2.9. Treatment of the raw agricultural commodities with acidified sodium chlorite solutions shall be followed by a potable water rinse, or Page 140 of 141 by blanching, cooking, or canning. ( f) The additive is used as an antimicrobial agent on processed, comminuted or formed meat food products ( unless precluded by standards of identity in 9 CFR part 319) prior to packaging of the food for commercial purposes, in accordance with current industry standards of good manufacturing practice. Applied as a dip or spray, the additive is used at levels that result in sodium chlorite concentrations of 500 to 1200 ppm, in combination with any GRAS acid at levels sufficient to achieve a pH of 2.5 to 2.9. ( g) The additive is used as an antimicrobial agent in the water applied to processed fruits and processed root, tuber, bulb, legume, fruiting ( i. e., eggplant, groundcherry, pepino, pepper, tomatillo, and tomato), and cucurbit vegetables in accordance with current industry standards of good manufacturing practices, as a component of a spray or dip solution, provided that such application be followed by a potable water rinse and a 24 hour holding period prior to consumption. However, for processed leafy vegetables ( i. e., vegetables other than root, tuber, bulb, legume, fruiting, and cucurbit vegetables) and vegetables in the Brassica [ Cole] family, application must be by dip treatment only, and must be preceded by a potable water rinse and followed by a potable water rinse and a 24 hour holding period prior to consumption. When used in a spray or dip solution, the additive is used at levels that result in sodium chlorite concentrations between 500 and 1,200 ppm, in combination with any GRAS acid at a level sufficient to achieve a solution pH of 2.3 to 2.9. ( h) The concentration of sodium chlorite is determined by a method entitled    Determination of Sodium Chlorite: 50 ppm to 1500 ppm Concentration,'' September 13, 1995, developed by Alcide Corp., Redmond, WA, which is incorporated by reference in accordance with 5 U. S. C. 552( a) and 1 CFR part 51.

Dietary Exposure Route 8. Chlorate ( ClO 3 b ) dietary exposure estimates from potential redox of sodium chlorite as the active ingredient in conventional ( agricultural) pesticides used in seed soak treatments These dietary exposure concerns are covered by the estimates from Dietary Exposure Route 4 discussed above.

Under 40 CFR 180.1070, sodium chlorite is exempted from the requirement of a tolerance for residues when used in accordance with good agricultural practice as a seed soak treatment in the growing of the raw agricultural commodities crop group Brassica ( cole) leafy vegetables and radishes. Page 141 of 141 Dietary Exposure Route 9. Chlorate ( ClO 3 b ) dietary exposure estimates from translocation of very small amounts of chlorate ion ( ClO 3 b ) by plants ( translocation of significant amounts would be phytotoxic to plants) from the environment which may be present due to inorganic chlorate pesticide uses These dietary exposure concerns are covered by the estimates from Dietary Exposure Routes 1, 2, and 4 discussed above.

REFERENCES Abdel Rahman MS, Couri D, Bull RJ. 1982. Metabolism and pharmacokinetics of alternate drinking water disinfectants. Environ Health Perspect. 46: 19 23.

Abdel Rahman MS, Couri D, Bull RJ. 1984b. The Kinetics of Chlorite and Chlorate in the Rat. Journal of the American College of Toxicology, 3( 4): 261 267.

Abdel Rahman MS, Couri D, Bull RJ. 1985. The kinetics of chlorite and chlorate in rats. J Environ Pathol Toxicol Oncol. 6( 1): 97 103.

Frank, G. 2002. Cost of Milk Production per Hundredweight Equivalent in Milk Sold per Cow Ranges. Wisconsin Dairy Data. Fact Sheet 2002 01. Center for Dairy Profitability. Univ. Wisconsin Extension Service. Oct. 2002.