Residues of plant protection products, ‘PPPs’, (pesticides used in crop protection) in food are a very important element of chemical contamination of food that is potentially harmful to human health. PPPs are one of the classes of so-called ‘contaminants’ in the World Trade Organisation’s SPS Agreement requiring all food safety measures applied to imports to be ‘scientifically justified’ and ‘non-discriminatory’ and hence PPP contamination has become a major issue in trade relations, particularly in the case of the European Union’s (EU) exports of food to the Russian Federation. After exploring PPP residues in the general context of food safety and in the context of international trade rules, this article investigates the legal basis of setting maximum residue limits (MRLs) in the EU and Russian Federation in comparison with the international standard MRLs set by the Codex Alimentarius Commission. Checklists on what MRL applies to a particular commodity in the EU and Russian Federation are also provided. Of particular note are the different approaches to ‘zero tolerance’ to particular PPPs. The claim of the Russian Federation to have adopted a higher standard of protection against PPP contamination of food than the EU is also examined in this context.