- PDF Version (236K) - Print Friendly - Help

Proposals to Amend the New Zealand (Maximum Residue Limits of Agricultural Compounds) Food Standards 2007

3 Proposal to set an MRL for Doramectin

It is proposed that an MRL is set for doramectin when used as an anthelmintic for sheep. It is proposed that Schedule One of the NZ (MRL) Food Standards 2007 be amended by deleting the following MRL:

As a replacement for the deleted MRL, it is proposed that Schedule One of the NZ (MRL) Food Standards 2007 be amended to include the following entry:

The final entry for doramectin in Schedule One of the NZ (MRL) Food Standards 2007 will therefore read:

Amendment Rationale

The proposed MRL represents a change in the use patterns of doramectin. The MRL will allow the use of doramectin as a subcutaneous injection to occur in sheep for the treatment of parasites. The increase in the MRL for sheep meat will harmonise New Zealand with MRLs currently in place in Australia and the European Union.

Chemical Information

Good Agricultural Practice

The proposed use of doramectin as an anthelmintic for sheep by way of subcutaneous injection is good agricultural practice (GAP) and aligns with uses in cattle and swine. The application rate is proposed at 0.02mgai/kg bw with a withholding period of 49 days.

Residues Information

Residue data for sheep meat supports an MRL of 0.02mg/kg at 49 days after the last treatment. An MRL of 0.02mg/kg is therefore proposed to support GAP.

Dietary Risk Assessment

The potential daily exposure via food (PDE_(food)) is used for dietary intake calculation where a value has been set. An appropriate acceptable daily intake (ADI) is used in the absence of a PDE_(food).

The chronic dietary exposure to doramectin is estimated by the National Estimated Dietary Intake (NEDI) calculation encompassing all registered uses of the chemical and food consumption data based upon the 1997 National Nutritional Survey for adults and the 1995 National Nutrition Survey of Australia, for children. The NEDI calculation is made in accordance with Guidelines for predicting dietary intake of pesticide residues (revised) [World Health Organisation, 1997].

The NEDI for doramectin is equivalent to 14% of the ADI. It is therefore concluded that the chronic dietary exposure is small and the risk is acceptable.

Toxicological / Public Health Assessment

It has been determined that the use of doramectin as an anthelmintic for use in sheep, according to the GAP specified above, is very unlikely to pose any health risks from consumption of the harvested commodity.

International MRLs

To meet New Zealand’s obligations under the Agreement on the Application of Sanitary and Phytosanitary Measures the proposed MRL will be notified to the World Trade Organization. Any country may choose to comment if they believe the proposed MRL represents a barrier to their trade.