Parathion-methyl review history and regulatory outcomes

Nomination for review

In 1996 the APVMA (formerly the NRA) began a review of parathion-methyl as part of the former Existing Chemical Review Program. Parathion-methyl was nominated for review because of concerns over worker health and safety, and the potential for adverse environmental effects, including its high toxicity to bees.

Draft report

In July 1998 the APVMA released the Parathion-methyl Draft Review Report* for public comment. The period for public comments and the submission of additional information closed on 31 December 1999.

The draft report highlighted significant concerns relating to the existing use patterns for parathion-methyl which had the potential to pose a high level of occupational exposure risk and have adverse environmental impacts. The APVMA noted there were significant gaps in the existing data on existing use patterns, toxicology, occupational health and safety, residues and the potential risks to the environment. These data gaps meant that more information had to be assessed before the use of parathion-methyl in Australia could be confirmed.

Interim Review Report

In March 1999 the APVMA released the Parathion-methyl Interim Review Report. The APVMA concluded that there were concerns over some existing use patterns for parathion-methyl and that more information was required.

The APVMA found that the direct overspray or spray drift from the aerial application of parathion-methyl had the potential to adversely affect bees and other native terrestrial insects, as well as sensitive aquatic fauna.

The APVMA also found that the risk to agricultural workers during ground spraying of parathion-methyl was unacceptable.

Due to the concerns raised in the interim report, the APVMA decided that the existing conditions of registration for products containing parathion-methyl were no longer appropriate. The APVMA decided to make changes to the conditions of registration of parathion-methyl products so that the use of these products in Australia could continue.

The APVMA implemented an ‘interim-use regime’ to reduce or eliminate the potential risk to workers and to the environment while the additional data relating to human health, occupational health and safety, residues, environment and aquatic toxicity were being generated. As of 31 December 1999, parathion-methyl products could only be supplied under the new label containing the interim changes.

The APVMA recommended the following interim-use regime:

• strengthening training and supply requirements: the APVMA recommended that a person using, keeping or disposing of parathion-methyl products should have successfully completed an appropriate course of training
• varying product labels to include stronger safety directions and occupational exposure warnings with respect to worker re-entry periods in treated crops
• varying product labels to include stronger warnings to protect the environment, such as use restraints and new instructions for disposal
• strengthening buffer zones and use patterns to minimise spray drift. Aerial application must use suitable spray drift minimisation strategies, such as large droplet placement technology, to limit environmental exposure
• strengthening withholding periods to 14 days for harvest and 14 days for grazing
• setting full MRLs for potato and sweet corn and temporary MRLs for vegetables, grapes, pome and stone fruits, meat, milk, cottonseed, cottonseed oil and animal feeds. These MRLs remain in force during the interim-use regime.

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 by email to chemrev@apvma.gov.au

* Contact the APVMA for copies of this document.