Sheep ectoparasiticides Chemical Review

In 1999, the APVMA began a review of selected sheep ectoparasiticides because of concerns about the potential environmental, occupational health and safety and trade risks from residues on treated wool.

In February 2000 the NRA Expert Panel on Organophosphate Sheep Dips (OP) 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 (July 1999). It concluded that work practices and exposure risks differed between Australia and the UK. However, the panel could not completely rule out a link between OP exposure and long-term effects on humans and the environment. The NRA expert panel recommended reducing worker exposure to OPs and that the APVMA review the uses of OPs on sheep.

There are a number of active constituents used as ectoparasiticides. Those considered by the APVMA during the review were alpha-cypermethrin, chlorfenvinphos, cypermethrin, cyromazine, deltamethrin, diazinon, dicyclanil, diflubenzuron, ivermectin, propetamphos, spinosad, temephos and triflumuron.

The review has focused on selected sheep ectoparasiticides for post-harvest wool and does not cover individual animal treatment products; nor does it include active constituents that are only approved for use on short wool (less than six weeks of wool growth).

The review does not consider occupational exposure during the application of ectoparasiticides.

In April 2006 the APVMA released the Sheep ectoparasiticides preliminary review findings report for public comment. The period for public comments and for the submission of additional information closed on 31 October 2006.

The APVMA concluded that the risks associated with chemical residues in treated wool could generally be reduced by making changes to product labels.

In the preliminary report the APVMA proposed varying product labels to include:

• a sheep rehandling interval
• a wool harvest interval
• and a trade advisory statement.

In June 2014 the APVMA released the final review findings report. The APVMA concluded that the risks associated with chemical residues on treated wool could be managed by making changes to product labels. The APVMA requires a wool harvest interval (WHI) and a sheep rehandling interval to be specified, and a generic trade statement to be included on the label.

The final review report incorporated the issues raised during the public consultation on the PRF Report. During the period between the publication of the PRF report and the final report, additional data had become available and the trade situation clarified.

The EU Commission Decision of 9 July 2009 establishes the ecological criteria for the award of the Community Ecolabel for textile products. It specifically addresses greasy wool and other keratin fibers (including wool from sheep, camel, alpaca and goat). Environmental Quality Standards (EQSs) have not been published in the EU for all active constituents in products affected by this review. There is now a commercial pesticide screening available to wool producers and exporters—services include EU Ecolabel verification which would meet the current EU requirements.

The APVMA concluded that the risks associated with chemical residues in treated wool could be reduced by making changes to product labels and maintaining use of the products by wool growers.

In the final review report the APVMA concluded that it was necessary to vary product labels to include:

• a sheep rehandling interval (SRI) statement indicating the interval from application to when the sheep can be safely handled without the need for protective equipment
• a safety statement advising the use of Personal Protective Equipment (PPE) if sheep are handled during the SR
• a wool harvest interval (WHI) statement which indicates the minimum interval from when the sheep are treated to when the sheep can be shorn
• a trade advisory statement
  • Wool treated with this product may contain detectable residues; adequate treatment records should be kept and made available, if requested by wool buyers.
  • Use of this product may result in wool residues that may not comply with European Union environmental quality standards.

A number of active constituents included in the sheep ectoparasiticides review (chlorfenvinphos, temephos, propetamphos and diazinon) have been or still are under review by the APVMA in their own right. This is to enable the APVMA to separately assess these active constituents, their uses and any concerns which may or may not include their use as sheep ectoparasiticides. While the active constituent reviews are being conducted separately, the outcomes of the ectoparasiticides review will be considered by the APVMA as part of those reviews.