Maximum Residue Levels (MRLs) for residues of pesticides
Pesticides (plant protection products) are used to protect crops from damage due to for example insects, fungi, bacteria, or weeds. It is estimated that about 1100 chemicals have been developed or isolated to be used as pesticides. Not all are still used however, as some are banned or obsolete.
The use of pesticides may result in residues on crop commodities. To protect the health of the consumer MRLs are set. Generally, not only safety concerns play a role however. When the use of a pesticide according to ‘Good Agricultural Practice’ leads to lower residue levels, these levels are used to set MRLs.
According to the Agreement on the Application of Sanitary and Phytosanitary Measures (SPM) and Agreement on Technical Barriers to Trade food safety standards for pesticide residues established by the Codex Alimentarius Commission are the reference points in international trade. Thus far, Codex established MRLs for about 225 pesticides (and for numerous pesticide/commodity combinations). Once accepted, member states of Codex are expected to implement these MRLs in national (or community) law. Deviations from Codex MRLs are possible but have to be substantiated with scientific proof of risk.
A lot of countries refer to Codex for the MRLs of pesticides (see http://www.fas.usda.gov/htp/mrl.asp ). The number of chemicals with Codex MRLs is however limited, the European Community (EC) for instance established pesticide MRLs for about 500 specific pesticides, and a default MRL of 0.01 mg/kg was established for all pesticides not mentioned by name in the EC Regulations. Achieving global harmonization of MRLs via Codex is an ongoing process.