Declining harmonization in maximum residue levels for pesticides

Maximum residual limits (MRLs) for pesticides are based on science. This is true both for MRLs devised by national governments and multilaterally through the Codex. Science-based Codex MRLs are internationally harmonized to facilitate trade. Since the 1990s, an increasing number of countries have devised national MRLs and eschewed those of the Codex. These differing national standards are becoming important barriers to trade. The purpose of this paper is to explore the ramifications of these diverging MRLs for food security, investigate the reasons for the rise of national standards, and explore the role of science in regulatory processes.

The approach is an examination of the scientific basis for MRLs in the context of food safety outcomes.

It finds that there is no improvement in food safety from the move to national MRLs, only a loss of the benefits of trade. As all countries, along with the Codex, claim that their MRLs are based on science, suggesting that there is a need for an examination of the role of science in the making of public policy.

This study identifies a potential risk to food security for food policy makers. Given future food security challenges and that pesticides are used almost universally in conventional agriculture, trade barriers based on divergent interpretations of science need to be addressed by food policy makers.