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Maximum Residue Limits (MRLs) for Agricultural Compounds in Food: The Purpose and Procedure for Determining MRLs

2 Background

2.1 What are MRLs?

Maximum Residue Limits (MRLs) indicate the maximum legal levels at which residues of agricultural compounds and veterinary medicines may be present in food for sale in New Zealand. The purpose of an MRL is to ensure that the methods of food production keep agricultural compound residues in food as low as reasonably achievable, thereby minimising risks to public health.

MRLs are primarily a tool for monitoring the use of agricultural compounds against good agricultural practice (GAP). GAP is not explicitly defined or regulated, but is the generally-accepted means of producing safe primary produce. GAP is about ensuring that chemical residues in food are as low as practicable, without compromising the ability of the chemical to successfully do what is intended.

In New Zealand, MRLs are set under the Food Act as food standards, namely the New Zealand (Maximum Residue Limits of Agricultural Compounds) Food Standards. These Standards amended a number of times each year to reflect changes in the use of agricultural compounds in the production of food. The current Standards are on the NZFSA website: http://www.nzfsa.govt.nz/policy-law/legislation/food-standards/index.htm

2.2 What is the Legislative Framework?

The MRL Standards are issued by the Minister for Food Safety under Section 11C of the Food Act 1981. The MRL Standards has been amended regularly since 1999, when it became the base standard for agricultural compound residues in foods as a parallel standard with regulation 257 of the Food Regulations 1984, which have since been revoked. The frequency of these amendments reflects new agricultural compounds coming on the market and changes in the registered uses of compounds already available.

NZFSA now administers the MRL Standards but the final decision on any changes to the Standards rests with the Minister for Food Safety. When amending or issuing any food standard, including the MRL Standards, the Minister must take into account the following:

• The need to protect public health

• The desirability of avoiding unnecessary restrictions on trade

• The desirability of maintaining consistency between New Zealand's food standards and those applying internationally

• New Zealand's obligations under any relevant international treaty, agreement, convention, or protocol, and, in particular, under the Australia-New Zealand Joint Food Standards Agreement

• Such other matters as the Minister considers appropriate.

Although residues of agricultural compounds in food for sale are regulated under the Food Act, the sale and use of the compounds themselves is regulated under the Agricultural Compounds and Veterinary Medicines Act 1997 (the ACVM Act). When an agricultural compound is registered under the ACVM Act, conditions are placed on the use of that product to ensure food residue limits are not exceeded.

The MRL Standards do not cover incidental contaminants that are not sold for use as agricultural compounds, such as heavy metals and natural toxicants. These are regulated in the joint Australia New Zealand Food Standards Code.

MRLs are excluded from the joint Australia New Zealand food standards-setting system, as MRLs which apply to the use of compounds to control pests, diseases and growing conditions are specific to each country.