PARATHION-METHYL FINAL REVIEW REPORT The reconsideration of the active constituent parathion-methyl, registration of products containing parathion-methyl and approvals of their associated labels NOVEMBER 2011 © Commonwealth of Australia 2011 This work is copyright. Apart from use permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from the Australian Pesticides and Veterinary Medicines Authority (APVMA). Requests and enquiries regarding reproduction and rights should be addressed to the APVMA’s Chemical Review Program Manager. ISBN 978-0-9871919-1-5 This document is published by the APVMA. In referencing this document the APVMA should be cited as both author and publisher. Comments and enquiries may be directed to: Manager Chemical Review Australian Pesticides & Veterinary Medicines Authority PO Box 6182 KINGSTON ACT 2604 Australia Telephone: +61 2 6210 4749 Facsimile: +61 2 6210 4776 Email: [email protected] Web site: http://www.apvma.gov.au i FOREWORD The Australian Pesticides & Veterinary Medicines Authority (APVMA) is an independent statutory authority with responsibility for the regulation of agricultural and veterinary chemicals in Australia. Its statutory powers are provided in the Agricultural and Veterinary Chemicals (Administration) Act 1992 (Administration Act) and the Agricultural and Veterinary Chemicals Code Act 1994 (Agvet Codes). The APVMA can reconsider the approval of an active constituent, the registration of a chemical product or the approval of a label for a container for a chemical product at any time. This is outlined in Part 2, Division 4 of the Agvet Codes. A reconsideration may be initiated when new research or evidence has raised concerns about the use or safety of a particular chemical, a product containing that chemical, or its label. The reconsideration process includes a call for information from a variety of sources, a review of that information and, following public consultation, a decision about the future use of the chemical or product. The information and technical data required by the APVMA to review the safety of both new and existing chemical products must be derived according to accepted scientific principles, as must the methods of assessment undertaken. In undertaking reconsiderations (hereafter referred to as reviews), the APVMA works in close cooperation with advisory agencies including the Office of Chemical Safety within the Department of Health and Ageing, the Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), and state and territory departments of agriculture, as well as other expert advisers as appropriate. The APVMA has a policy of encouraging openness and transparency in its activities and community involvement in decision-making. The publication of review reports is a part of that process. The APVMA also makes these reports available to the regulatory agencies of other countries as part of bilateral agreements. The APVMA recommends that countries receiving these reports will not utilise them for registration purposes unless they are also provided with the raw data from the relevant applicant. The basis for the current reconsideration is whether the APVMA is satisfied that continued use of the active constituent parathion-methyl and products containing parathion-methyl in accordance with the instructions for their use: would not be an undue hazard to the safety of people exposed to it during its handling would not be likely to have an effect that is harmful to human beings ii would not be likely to have an unintended effect that is harmful to animals, plants or things or to the environment would not unduly prejudice trade or commerce between Australia and places outside Australia. The APVMA also considered whether product labels carry adequate instructions and warning statements. This document is ‘The reconsideration of approvals of the active parathion-methyl, registrations of products containing parathion-methyl and their associated labels, final review report’. It relates to all products containing parathion-methyl that were nominated for review by the APVMA as well as those registered after the commencement of the review, whose registration is subject to the outcomes of the review. iii TABLE OF CONTENTS FOREWORD I EXECUTIVE SUMMARY VII Review findings viii Review status x 1. INTRODUCTION 1 1.1 Regulatory status of parathion-methyl in Australia 1 1.2 Reasons for parathion-methyl review 2 1.3 Scope of the review 2 1.4 Regulatory options 3 1.5 Interim use regime 4 2. APPROVED PARATHION-METHYL USE PATTERNS 6 2.1 Use patterns at the commencement of the review 6 2.2 Current use patterns (2011) 8 3. DATA ASSESSMENTS 10 3.1 Toxicology 10 3.1.1 Consideration of public health standards 10 3.1.2 Consideration of additional information 11 3.1.3 Discussion 17 3.2 Occupational health and safety (OHS) 20 3.2.1 Interim report 20 3.2.2 Assessment of additional information 21 3.2.3 Occupational exposure 23 3.2.4 Exposure assessment 25 3.2.5 Occupational risk assessment 36 3.2.6 Summary and conclusions 45 3.2.7 Review outcomes 46 3.3 Environment 49 3.3.1 Conclusions from the interim report 49 3.3.2 Supplementary data assessment 51 Summary 65 3.4 Residues 66 3.4.1 Interim report 66 3.4.2 Recent consideration 68 4 OVERSEAS REGULATORY ACTION 69 United States 69 Europe 69 5 REVIEW STATUS 70 iv APPENDIX A—ACTIVE CONSTITUENT AND PRODUCTS INCLUDED IN THE REVIEW 72 APPENDIX B—MAIN TOXICOLOGY ASSESSMENT 73 Study: Beyrouty P (2001) 73 Results 76 Studies: Weiler MS (1999b)and Gains M (1999b) 82 Results 84 FOB findings 84 Motor activity 84 Consumption of test diets 84 Consumption of test substance 85 Cholinesterase activity 85 Histopathology 87 Comments 88 Studies: Cockrell (), Brennecke (1996), O’Shaughnessy D (2000) and Jortner BS (2001) 89 Cockrell (1992) 89 Brennecke (1996) 91 O’Shaughnessy (2000) 92 Jortner (2001) 94 Results 94 Comments 96 APPENDIX C—OCCUPATIONAL HEALTH AND SAFETY STUDY DETAIL AND DISCUSSION 97 Worker exposure to parathion-methyl in the course of open mixing/loading 97 Worker exposure to parathion-methyl in the course of closed mixing/loading 105 Worker exposure to parathion-methyl in the course of application to potato (broadacre crops) 107 Worker exposure to parathion-methyl in the course of entering fields post application activities (re-entry exposure) 110 Determination of dislodgeable foliar residues (DFR) in plant foliage treated with parathion-methyl (Re-entry exposure) 116 DFR studies in apple crops 116 DFR studies in sweet corn 118 REFERENCES 128 Toxicology 128 Occupational health and safety 130 Environment 132 ACRONYMS AND ABBREVIATIONS 133 v LIST OF TABLES Table 1: Crops on which parathion-methyl is used 1 Table 2: Products affected by review findings 2 Table 3: Active constituent information 9 Table 4: Oral neurotoxicity studies 14 Table 5: Dermal neurotoxicity studies 16 Table 6: PHED estimates of dermal and inhalation exposure to parathion-methyl during mixing/loading and application 25 Table 7: Summary of exposure studies for workers during mixing/loading and application of parathion-methyl products 26 Table 8: Dermal and inhalation exposure to parathion-methyl during mixing/loading and application estimated from PHED dataset 27 Table 9: Dermal exposure estimates to parathion-methyl calculated from the dislodgeable foliar residues (DFR) and transfer coefficient values for various re-entry activities in apple crops 28 Table 10: Transfer coefficients calculated for irrigation and harvesting of sweet corn 30 Table 11: Dermal exposure estimates to parathion-methyl, calculated from the dislodgeable foliar residues (DFR) and transfer coefficient (TC) values for various re-entry activities in sweet corn crops following parathion- methyl application (ME formulation) 31 Table 12: Transfer coefficient calculated for scouting of cotton crops 32 Table 13: Dermal exposure estimates to parathion-methyl, calculated from dislodgeable foliar residues (DFR) and transfer coefficients for various re-entry activities in cotton crops following parathion-methyl application (ME formulation) 33 Table 14: Dermal exposure estimates to parathion-methyl, calculated from dislodgeable foliar residues (DFR) and transfer coefficients for various re-entry activities in cotton crops following parathion-methyl application (EC formulation) 35 Table 15: MOEa for workers mixing/loading (for aerial and ground application) and applying parathion-methyl to broadacre crops (ground application) 38 Table 16: Margin of exposure (MOEa) for workers mixing/loading (open and closed systems) and applying parathion-methyl to broadacre crops (PHED estimates) 39 Table 17: Margin of exposure (MOE1) for re-entry activities determined from dislodgeable foliar residues (DFR) after application of two different products of parathion-methyl on apples and using generic2 transfer coefficients for apple crops. 40 Table 18: Margin of exposure (MOE) for re-entry activities determined from the DFR values following application of ME formulation of parathion-methyl on sweet corn and using calculated2 and generic3 transfer 1 coefficients (TC) for sweet corn 43 Table 19: Margin of Exposure (MOE) for re-entry activities determined from the DFR values following application of two different formulations of parathion-methyl in cotton crops and using calculated2 and generic3 transfer coefficients (TC) for cotton 44 Table 20: Toxicity results (in g/L) for individual actives 53 Table 21: Toxicity results for the combined toxicity