AUSTRALIAN PESTICIDES AND VETERINARY MEDICINES Australian Pesticides and Veterinary Medicines Authority

1

AUSTRALIAN PESTICIDES AND VETERINARY MEDICINES AUTHORITY

NATIONAL REGISTRATION SCHEME

FOR AGRICULTURAL AND VETERINARY CHEMICALS

AUSTRALIA

CHEMICAL REVIEW PROGRAM

OCCUPATIONAL HEALTH AND SAFETY ASSESSMENT

OF

FIPRONIL

Prepared by the

Office of Chemical Safety and Environmental Health

Office of Health Protection

of the

Department of Health and Ageing

Canberra

Finalised March 2008

Amended May 2009

Amended September 2009

TABLE OF CONTENTS

1 EXECUTIVE SUMMARY .................................................................................................... 6

2 INTRODUCTION ................................................................................................................ 7

3 FIPRONIL PRODUCTS AND THEIR USE PATTERNS .................................................... 8

3.1 Label information and current safety directions ........................................................ 14

3.2 Use pattern of fipronil products ................................................................................. 18

3.3 Methods and types of equipment used for mixing/loading/application of fipronil products ............................................................................................................................... 27

3.4 Label restrictions ....................................................................................................... 28

4 TOXICOLOGICAL HAZARD OF FIPRONIL .................................................................... 30

4.1 Acute toxicity ............................................................................................................. 30

4.1.1 Fipronil ............................................................................................................... 30

4.1.2 Fipronil metabolites ............................................................................................ 30

4.1.3 Fipronil products ................................................................................................ 31

4.2 Repeat-dose toxicity .................................................................................................. 31

5 TOXICOLOGICAL ENDPOINTS FOR OHS RISK ASSESSMENT ................................. 33

5.1 Dose levels relevant to risk assessment ................................................................... 33

5.2 Short-term NOEL (for assessing risk to farmers and contract workers) ................... 36

5.3 Long-term NOEL (for assessing risk to pest control operators (PCOs))................... 36

5.4 NOEL for re-entry interval calculations ..................................................................... 36

6 ASSESSMENT OF OCCUPATIONAL EXPOSURE DURING PRODUCTION ............... 37

7 ASSESSMENT OF OCCUPATIONAL EXPOSURE AND RISK WHEN HANDLING FIPRONIL PRODUCTS ........................................................................................................... 38

7.1 Evaluation of exposure studies ................................................................................. 38

7.2 Exposure assessments performed by registrants ..................................................... 52

7.3 Estimation of occupational exposure and risk ........................................................... 70

7.3.1 Determination of Occupational Exposure .......................................................... 73

7.3.2 Risk estimates from combined dermal and inhalation exposure ....................... 79

7.4 Occupational risk characterization ............................................................................ 79

7.4.1 Dermal and Inhalation Margins of Exposure (MOEs) ........................................ 79

7.4.2 Combined Dermal and Inhalation MOEs ........................................................... 79

7.4.3 Evaluation of worker risk estimates ................................................................... 89

8 ASSESSMENT OF POST-APPLICATION EXPOSURE .................................................. 93

8.1 Post application exposure ......................................................................................... 93

8.2 Exposure assessment of re-entry workers ................................................................ 93

8.3 Estimation of dermal exposure and safe re-entry periods ........................................ 93

8.4 Calculated Risk from Occupational Post-application Exposure ................................ 94

9 DISCUSSION ................................................................................................................... 99

10 SAFETY DIRECTIONS AND RE-ENTRY INTERVALS ............................................. 102

10.1 Safety directions .................................................................................................. 102

10.2 Re-entry intervals ................................................................................................ 106

10.3 Re-entry/re-handling statements ......................................................................... 107

10.4 Exposure mitigation methods .............................................................................. 107

11 RECOMMENDATIONS TO THE APVMA .................................................................. 108

12 REFERENCES ........................................................................................................... 114

13 APPENDIX I – Fipronil products assessed in the toxicology review .......................... 121

14 APPENDIX II - Overseas Regulatory Assessments/Actions ...................................... 123

15 APPENDIX III – EXPOSURE MITIGATION MEASURES .......................................... 125

TABLES

Table 1: Summary of fipronil products assessed in this report ................................................. 9

Table 2: Use pattern of fipronil products ................................................................................. 19

Table 3: Withholding periods and other restrictions for fipronil products ................................ 28

Table 4: Summary of relevant NOELs from repeat-dose studies for fipronil ........................... 34

Table 5: Worker exposure during application of Regent 20GR in banana plantation ............. 40

Table 6: Fipronil vapour detected in indoor air on day of application ...................................... 42

Table 7: Summary of respiratory exposure for PCO applying fipronil product ........................ 43

Table 8: Summary of applicator exposure following treatment of dogs with Frontline Spray Treatment ......................................................................................................................... 46

Table 9: Summary of applicator exposure following treatment of dogs with Frontline Top Spot .......................................................................................................................................... 50

Table 10: Surrogate exposure data (PHED) for termiticide injection method ......................... 53

Table 11: Exposure and MOE values for PCO using Termidor WG ....................................... 57

Table 12: Estimated exposure to fipronil by dermal and inhalation routes for each task. Spray concentration: 357 g/L (Italy) ............................................................................................ 59

Table 13: Estimated exposure to fipronil by dermal and inhalation routes per task and per day. Spray concentration: 143 g/L (France) ............................................................................. 60

Table 14: Distribution of dermal exposure for each task ......................................................... 60

Table 15: Summary of estimated exposure during various seed treatment tasks .................. 62

(Italian use pattern) .................................................................................................................. 62

Table 16: Summary of estimated exposure during various seed treatment tasks .................. 63

(French use pattern) ................................................................................................................ 63

Table 17: Total absorbed dose and risk characterisation (% AOEL) of workers using fipronil product to treat maize seeds (including exposure during calibration) .............................. 64

Table 18: Total absorbed dose and risk characterisation (% AOEL) of workers using fipronil product to treat maize seeds (exposure during calibration not included) ........................ 65

Table 19: Exposure from treatment of median number of dogs during peak infection season* (Frontline Spray Treatment) ............................................................................................. 68

Table 20: Exposure from treatment of median number of dogs during peak infection season* (Frontline Top Spot) ......................................................................................................... 69

Table 21: Dermal and inhalation exposure estimates (using PHED database) ...................... 75

Table 22: Occupational exposure estimated from PHED data-subsets and dermal, inhalation and t