Many potentially dangerous chemical ingredients are used and additional chemicals are formed during manufacture. Meth manufacture creates the potential for explosions, chemical fires, and the release of toxic gases. The processes also result in sludge and liquid wastes with the potential to contaminate a structure and its contents, the air, and the groundwater or soil where they are deposited. Five to seven pounds of chemical waste is produced for each pound of meth manufactured. After a lab has been abandoned or shut down by law enforcement, the property is usually found to be contaminated with hazardous chemicals.
Clandestine labs use improvised equipment, without regard to safety.
An example is the frequent use of propane tanks to hold pressurized corrosive anhydrous ammonia. Ammonia corrodes the brass fittings on propane tanks creating the potential for leakage or explosion. The labs being found in Minnesota are mostly temporary, makeshift operations set up in apartments, storage facilities, motel and hotel rooms, campsites, fields, vacant buildings, and vehicles. Discarded lab equipment and chemical waste are also being found in roadside ditches. Health effects caused by exposure to meth lab chemicals depend on the process and chemicals used, the amount of chemical and length of exposure, and the health of the person being exposed.