Public concerns about food safety issues often place Codex at the centre of global debates. Veterinary drugs, pesticides, food additives and contaminants are some of the issues discussed in Codex meetings. Codex standards are based on sound science provided by independent international risk assessment bodies or ad-hoc consultations organized by FAO and WHO. 

While being recommendations for voluntary application by members, Codex standards serve in many cases as a basis for national legislation.

http://www.fao.org/fao-who-codexalimentarius/codex-texts/guidelines/en/