Proposed revision of registration requirements for sheep ectoparasiticide products

This notice outlines changes being considered by the NRA to the registration requirements for sheep ectoparasiticide products. If adopted, the revised requirements will apply immediately to all current and future applications for product registration (or relevant permit approvals). In addition, all existing registered products will be required to satisfy the NRA that they meet these new requirements for continued registration of the product or for continued label approval, or permit approval of the product, as the case may be.

Occupational Health & Safety

The updated OH&S criteria to be met, and data requirements, are described in the revised protocol developed by the National Occupational Health and Safety Commission (NOHSC), entitled “Guidelines for Conducting a Health Risk Assessment of Sheep Ectoparasiticides for Wool and Sheep Handlers”, published 23 June 1999, which will be incorporated into the NRA’s Requirements Manual. Copies of this guideline can be obtained from the NRA or direct from the NOHSC website at www.worksafe.gov.au.

Registrants will be required to show on the label a rehandling period which is defined as the period between treatment and when sheep can safely be handled without the need for protective clothing. In the event that sheep need to be handled before expiry of the re-handling period, then suitable protective clothing will be required.

Environment

The primary focus of the updated environmental requirements is on the discharge of liquid effluents directly, or indirectly through sewage treatment facilities, to land, ocean or riverine discharge points. However registrants should also address environmental aspects of the disposal of any pesticide-contaminated sludges retained on-site by wool processors following on-site effluent treatment. In most cases, these sludges are disposed of at some form of landfill disposal site.

For assessment purposes, the worst case scenario for ocean discharge is considered to be the ocean sewage outlet of Barwon Water’s (Geelong) sewage treatment plant at Black Rock in Victoria, Australia. Although environmental requirements at Black Rock tend to focus on acute toxicity (LC50) figures in the most sensitive species, in the case of more persistent pesticides such as the insect growth regulators, consideration should also be given to providing longer term chronic toxicity data.

The worst case scenario for riverine discharge is considered, for assessment purposes, to be that represented by the former scouring plant at Spenborough in the UK which is similar to other scouring situations in Europe. Two environmental requirements will need to be addressed:

(a) annual average Environmental Quality Standards (EQS) which are based on annual average emissions from scouring plants under average river flows and take into account the chronic exposure hazard of the pesticide to the most sensitive aquatic organisms; and
(b) a maximum allowable concentration (MAC), which is allowable for short periods of time only and which is based on acute toxicity hazard (short term exposure) under conditions of low river flow. These MAC concentrations are estimates of acute no-effect concentrations (EC0) in the most sensitive aquatic species and this is a more severe requirement than that suggested for ocean discharge in Australia, which tend to be based on LC50 data.

Registrants will be expected to propose two critical environmental residue concentrations (ie maximum acceptable residue limits) for residues in harvested raw wool – one that would allow wool processors to meet environmental requirements in Australia, and the other for Europe. The need to meet the European environmental standards directly affects the requirement that the use of ectoparasiticide products would not unduly prejudice trade or commerce between Australia and places outside Australia (see below).

Australian environmental requirements are considered to be those applicable to the ocean discharge point at Black Rock in Victoria, while European requirements are those applicable to the former scouring plant at Spenborough in the UK. Allowance for the percentage of the national flock treated with the pesticide in question and the blending practices that occur at wool processing plants should be taken into account when proposing critical environmental residue concentrations.

Registrants will also be expected to propose corresponding wool harvesting intervals (ie the period that must elapse between treatment and harvesting, either by shearing or fellmongering) for both Australian and European environmental requirements.

Procedures for assessing the environmental impact of liquid effluent to land, ocean or riverine discharge, critical environmental residue concentrations and wool harvesting intervals are described in Savage (1998). More detailed guidelines are currently being prepared.

Registrants will have the option of proposing alternative assessment procedures and assumptions, as well as more appropriate data to those used by Savage (1998).

Trade

The major threat to trade at present is the possibility of residues in scouring effluent exceeding proposed environmental requirements which are expected to be progressively adopted by European Union member states between October 1999 and October 2007. As mentioned above, European requirements are considered to be the environmental requirements that the former scouring plant at Spenborough, in the UK, would have been expected to meet.

Registrants will be required to propose an export wool harvesting interval, which is the period between treatment and when wool can be harvested for export.

Label requirements

The Australian Wool Residues Management Council has recommended that label recommendations for sheep ectoparasiticides be based on the Australian environmental requirements for the ocean outfall at Black Rock, and that it would be prepared to explore options for providing growers with advice on the residue requirements of importing countries. The NRA is also mindful of the animal welfare implications of imposing restrictions on the use of sheep ectoparasiticides in long wool.

Consequently, registrants of sheep ectoparasiticides will be required to show the following information on the product label:

(a) required meat and milk withholding periods
(b) a shearing rehandling period (as defined above); and
(c) a wool harvesting interval based on Australian environmental requirements (as defined above).

The meat and milk withholding periods will be shown in the withholding periods panel of the label, while the rehandling period will be shown in the restraints panel, together with any required protective clothing statements. These restrictions will be mandatory on product users.

The wool harvesting interval will be shown in the advisory panels of the label in a statement along the following lines:

“Wool harvesting interval
Use of this product may result in residue levels in harvested wool that are unacceptable to Australian and overseas wool processors. It is advisable that wool not be harvested for at least ‘x’ months after treatment. If sheep are treated within this wool harvesting interval, treated sheep and wool must be identified to intending buyers by vendor declaration and/or a certificate of analysis, to enable treated wool to be processed in a manner which minimises environmental harm. Longer withholding periods may be necessary for wool intended for certain overseas markets. For further information, including information on overseas trade requirements, contact 1800 phone number”.

Note that this wool harvesting interval is not mandatory on users, and its advisory nature is dependent on the Wool Industry being able to develop a mechanism for identifying treated wool and sheep, as well as providing relevant advice on residue requirements of importing countries.

If the Wool Industry is unable to develop a mechanism for identifying treated wool and sheep to intending buyers, or provide appropriate advice on residue requirements of importing countries, alternative options may need to be considered.

Further comment sought

The NRA’s consideration of the residue implications of sheep ectoparasiticides has included extensive consultation. The outcomes and recommendations developed and reported by the NRA in “The Residue Implications of Sheep Ectoparasiticides” have been available for comment since November 1998. The NRA now invites written comments from interested parties related to the above proposed amendments to the NRA’s registration requirements for sheep ectoparasiticides. Written comments should be received by the NRA within 28 days of the date of this notice and should be forwarded to

Joan Ashton
Sheep Ectoparasiticide Review Coordinator
National Registration Authority
PO Box E240
KINGSTON ACT 2604

For more information concerning the above please contact Joan Ashton on telephone (02) 6271 6375, facsimile (02) 6271 6442 or via e-mail on jashton@nra.gov.au.

Reference

Savage GFJ (1998) “The Residue Implications of Sheep Ectoparasiticides – a Report for The Woolmark Company”. NRA Report, Nov 1998. Copies of this report are available either from the NRA or on the NRA’s web site.