The purity of methamphetamines and the violence associated with the drugs have increased over the past several years. Precursor chemical suppliers and their products play a pivotal role in methamphetamine production. Two supply sources for precursor chemicals are the domestic chemical industry from which ephedrine, pseudoephedrine, and other essential chemicals and solvents are diverted and the international chemical market which feeds methamphetamine production in the United States through Mexico and Canada. Beginning in 1990, however, new U.S. laws have reduced the availability of domestic chemicals needed for methamphetamine production. At the same time, the involvement of Mexican drug trafficking groups in methamphetamine production has increased, and methamphetamines are being distributed by numerous domestic organizations working with Mexican drug traffickers. Environmental considerations related to chemical fires and hazardous waste disposal at methamphetamine production laboratories are considered, and DEA efforts to educate chemical companies about the seriousness of the methamphetamine problem are noted. 2 photographs