APVMA reconsidering pesticide thiophanate-methyl

The Australian Pesticides and Veterinary Medicines Authority (APVMA) is reconsidering the approvals, registrations and product labels associated with the active constituent thiophanate-methyl. This is based on concerns about potential risks to occupational health and safety and public health.

The APVMA invites comment on the preliminary findings and proposed actions in the Thiophanate-methyl Preliminary Review Findings Report (PDF, 712kb) from 3 August 2010 to 31 August 2010.

This report is the first of two stages in the review process. Comments on this report will be assessed by the APVMA (and partner agencies where required) prior to finalisation of the review and publication of the Final Review Report and Regulatory Decision.

Thiophanate-methyl is a systemic fungicide used in Australia to control soil borne diseases in ornamental plants.

Thiophanate breaks down in plants and the environment to form carbendazim and the use of thiophanate-methyl can lead to residues of carbendazim in treated commodities.  For this reason the APVMA began a review of thiophanate-methyl in 2007.

The key preliminary findings of the review of thiophanate-methyl were as follows:

• unlike benomyl and carbendazim, thiophanate-methyl did not induce similar birth defects in animal studies following force-feeding of large doses.  While thiophanate-methyl breaks down in the environment to form carbendazim, in mammals thiophanate-methyl appears to undergo only very limited metabolic conversion to carbendazim;

• the use of products containing thiophanate-methyl in accordance with amended label instructions would not be likely to have a harmful effect on human health;

• the existing safety directions, poison scheduling and personal protective equipment (PPE) for thiophanate-methyl products remain appropriate, apart from a minor label change.  In addition, the re-entry interval and first aid instructions require minor changes to the product label;

• the restraint “NOT FOR HOME GARDEN USE” should be added to all product labels to clarify that thiophanate-methyl products are for professional use only.

Full report