- PDF Version (2.4M) - Print Friendly - Help

AgVetLink: Number 62, June 2007

MRL update

The public consultation period on amendment 1 to the MRL standard closed on 12 June 2007. The amendment will now undergo final administration and sign-off before it is Gazetted in mid to late July. Amendment 1 proposed to set the following MRLs:

* Indicates that the MRL has been proposed at or about the limit of analytical quantification.

Second amendment

Public consultation on the second amendment of the year will soon begin. This amendment will propose to set MRLs for nine agricultural compounds and an MRL exemption for one veterinary medicine. Amendment 2 will also propose to include a generic exemption for microbial pesticides into Schedule 2 of the MRL standard as follows.

Background

The purpose of the New Zealand (Maximum Residue Limits of Agricultural Compounds) Food Standard (MRL standard) is to define the maximum levels of agricultural compounds in food commodities to provide regulation for good agricultural practice (GAP). The MRL standard defines a maximum concentration for a single or combination of chemical residues that is expected to occur from the use of an agricultural compound product. However, this relies solely on the ability to detect and distinguish a significant chemical residue, so it cannot be applied universally to all agricultural compounds. To allow for this the standard also contains Schedules 2 and 3 which detail cases where it has been determined that certain compounds or organisms do not fit the MRL criteria and thus have been exempted from the requirement of having an MRL defined.

Proposal

The requested amendment to the MRL standard includes a generic exemption for microbial pesticides into Schedule 2 (exemptions for plant compounds) on the basis that microbial pesticides do not fit the standard's criteria of an MRL. The primary rationale for this determination is that, as organisms, the majority of microbial pesticides do not leave a typical chemical residue; therefore, to regulate their use through setting a defined residue limit is not feasible. As many of the currently used microbial pesticides are also indigenous to the environment, the determination of a residue figure becomes complicated by variation in background levels. There are exceptions to this determination in that certain microbial pesticides act through the production of microbial toxins to produce the desired pesticidal effect. The proposal would omit these organisms from the generic exemption. For example, this situation will be the case for Bacillus thuringiensis, which acts as an insecticide through the formation of delta-endotoxins that may leave a detectable chemical residue in certain cases. Bacillus thuringiensis will remain as a separate MRL exemption in Schedule 2.

While this proposed MRL exemption will allow applicable microbial pesticides to be exempted from the requirement of complying with the MRL standard, it will not affect the requirements these organisms and products containing these organisms have under other legislation.They still have a requirement to be assessed and registered as agricultural compounds under the ACVM Act. In undertaking such registration, applicants are still required to identify that the use of their product represents GAP and that there is no risk to public health from the consumption of treated food commodities. (This latter risk assessment is reinforced by the provision of a condition to prevent organisms pathogenic or toxic to humans to be included within the MRL exemption.) In addition, prior to its registration under the ACVM Act, if it is considered a hazardous substance or a new organism, it must have an approval under the HSNO Act.

Finally, there may be situations other than those specified in the exemption conditions where NZFSA does not feel an organism is suitable to be encompassed by the generic exemption. This is managed through the clause: "Except where otherwise stated in the NZ (MRL) Food Standards 2007". This gives NZFSA the ability to determine a specific MRL or separate exemption where necessary in the best interests of managing the use or residues of the organism.