The first United Nations Office on Drugs and Crime (UNODC) Guidelines for the Safe Disposal of Chemicals used in the illicit manufacture of Drugs (STNAR/36) was published in 2006. At the 33rd meeting of the Heads of Law Enforcement Agencies (HONLEA) Asia and Pacific, in Bali, Indonesia in 2010, Member States noted the significant increase in precursor chemicals discovered regionally and expressed concern about the difficulties encountered in storing and disposing of precursor chemicals in a safe and environmentally friendly manner. The present Guidelines reflect the discussions of the experts at the Expert Group Meeting on Safe and Environmentally-Responsible Disposal of Chemicals Used in the Illicit Manufacture of Drugs held in Bangkok, Thailand, from 20 to 22 September 2010, and the elaboration of practical methods for the safe handling and disposal of seized chemicals in situations where a waste management infrastructure may not be available.