The most immediate dangers of a clandestine drug lab in a building is the risk of fire or explosion. Because of the nature of the chemicals used to produce drugs such as methamphetamines in clandestine laboratories, escaping fumes can cause serious danger to people, even if they are not in the room or building where the lab is. The chemicals can cause central nervous system damage and other health risks. Even after a clandestine drug lab has ceased operations, there are still serious risks. Residue from fumes and spills settle on surfaces and are extremely dangerous.