During controlled "cooks" by National Jewish Medical and Research Center, phosphine was generated during the hypophosphorous methamphetamine "cooks". Phosphine was produced at concentrations measured from Non-detectable to 13 ppm during the cooking phase. The current ACGIH TLV for phosphine is 0.3 ppm on an eight-hour time weighted basis with a STEL of 1.0 ppm(12)

The highest level observed was 13 times the STEL, suggesting that overexposure to phosphine is likely. Phosphine is a severe pulmonary irritant that may cause dyspnea, headache, paresthesia, diplopia, tremor, jaundice, and pulmonary edema. Death from exposure to phosphine used an an insecticide has occurred in exposed persons.(15) Fatalities thought to be due to phosphine exposure were also linked to a methamphetamine laboratory in Los Angeles, CA where three persons were found dead in a motel room.(16)

A laboratory investigator was also reported by Burgess (17) to have developed dizziness, dry cough, headache, and diarrhea, with a delayed onset of cough and dyspnea, after investigating a clandestine methamphetamine laboratory. The exposure was measured at 2.7 ppm phosphine and the duration of exposure was approximately 20-30 minutes. These levels are in the same range as the levels measured during our investigation. In workers, phosphine exposure has been shown to cause gastrointestinal, respiratory, and central nervous symptoms at concentrations that are less than 10 ppm.(18)

There are a number of reasons why phosphine intoxication may be more common than reported. Phosphine does have a detectable odor but it may be less readily identified with the presence of the more odorous hydrocarbons present during the"cook". In addition, the pulmonary toxicity of phosphine may occur shortly after exposure or it may be delayed for 18 hours or more. These factors may result in fewer reported symptoms, although pulmonary irritation is a common complaint after a clandestine laboratory investigation.

Children and adults that are especially susceptible to pulmonary problems, such as asthmatics, individuals with chronic obstructive pulmonary disease, emphysema, etc, may show significantly greater effects to exposure levels of phosphine that are well below the concentrations allowed in the occupational environment.

Additional Information:

NIOSH Pocket Guide to Chemical Hazards: Phosphine

Office of Enviornmental Health Hazard Assessment:Phosphine

Technical Support Document Toxicology Clandestine Drug Labs: Phosphine