Chlorfenvinphos review history and regulatory outcomes

Nomination for review

In Dec 1996 the APVMA (formerly the NRA) began a review of chlorfenvinphos as part of the Existing Chemical Review Program (ECRP) which was established to systematically review a number of Agvet chemicals which had been on the Australian market for some time. Chlorfenvinphos was nominated for review because of concerns over worker health and safety and its potential to cause adverse environmental effects.

Draft report

In Sep 1999 the APVMA released the Chlorfenvinphos Draft Report*. The draft report concluded that there were gaps in the worker safety and environment data. These gaps meant that more information had to be assessed before the continued use of chlorfenvinphos in Australia could be confirmed.

In November 1999 the review of chlorfenvinphos was put on hold pending the findings of the NRA Expert Panel on Organophosphate Sheep Dips. The panel reviewed the findings of the UK Institute of Occupational Medicine (IOM) report, Epidemiological study of the relationship between exposure to organophosphate pesticides and indices of chronic peripheral neuropathy, and neuropsychological abnormalities in sheep farmers and dippers (Jul 1999). The IOM report found that the main source of exposure to organophosphates was in the handling of organophosphate concentrates rather than working with the diluted dip solution. It concluded that there was a link between organophosphate exposure and chronic health effects.

In Feb 2000 the panel completed its review and found that work practices and hence exposure risks differed between Australia and the UK. However, the panel could not completely rule out a link between organophosphate exposure and long-term effects. Based on this finding, the panel made a series of recommendations to the APVMA to minimise worker exposure to organophosphorus compounds.

Interim Review Report

In Dec 2000 the APVMA released the Chlorfenvinphos Interim Review Report which incorporated the recommendations made by the NRA Expert Panel. The APVMA concluded that there were concerns over the current occupational health and safety use patterns for chlorfenvinphos.

The APVMA also concluded that there was a lack of Australian data on the stability of chlorfenvinphos in storage and on any potential occupational health and safety risks (for hand spraying of cattle only). The APVMA requested that registrants provide this additional information by 31 Dec 2003.

The registrants of WSD Jetting fluid, Birlane 500 Insecticide, and Coopers Suprex 100 Jetting Fluid advised the APVMA that they would not be providing additional data and voluntarily withdrew the registration of their products (effective 8 November 2000 and 11 Dec 2000 respectively). The APVMA granted a two-year period for the phase out of existing stocks.

However, the APVMA was satisfied that the use patterns of chlorfenvinphos could be varied to manage the potential risks identified in the report. In the interim report the APVMA proposed a number changes to the conditions of registration and product labels. The APVMA also implemented an ‘interim use regime’ to reduce or eliminate the potential risk to workers while the additional data were being. As of 31 Dec 2000, chlorfenvinphos products could only be supplied under the new label containing the interim use regime changes.

In the report APVMA introduced the following interim use regime:

• including label warning statements to reduce the potential for worker exposure and the release of products into the environment
• modifying the design of containers in order to reduce worker exposure during the mixing/loading of chlorfenvinphos, with effect from 31 Dec 2002
• varying product labels to indicate that only hand-spraying is permitted for cattle by including the words ‘Hand sprays and non-recirculating spray races CATTLE ONLY’
• restricting the use of some products in lactating animals
• cancelling the registration of all agricultural products containing chlorfenvinphos because of occupational and safety and environmental concerns
• deleting all Maximum Residue Limits (MRLs) which relate to agricultural applications of chlorfenvinphos, with effect from 30 Dec 2002.

These were put in place in Dec 2000 and continue to remain in force.

The APVMA will issue a final report once the assessment of all available data is completed.

For more information please contact the Chemical Review Program on (02) 6210 4749 or at chemrev@apvma.gov.au

* Contact the APVMA for copies of this document.