Muscle relaxants

Occupational exposure to inhalational anaesthetics has often been associated with health hazards and reproductive toxicity, but the available evidence is weak and comes mostly from epidemiological studies that have been criticized. Studies based on registered data generally showed no association between occupational exposure to inhalational anaesthetics and reproductive effects. Animal studies also showed a lack of carcinogenicity, organ toxicity and reproductive effects with trace concentrations, as observed in operating rooms. The exception may be nitrous oxide, which in some, but not all, studies showed teratogenicity in rats chronically exposed to concentrations of 1000 p.p.m. and higher, such as may occur in unscavenged operating rooms lacking a mechanical ventilation system. Occupational exposure has also been associated with impairment of psychological functions, but these effects do not occur with trace concentrations. All in all, the scientific evidence for hazards is weak. Nonetheless, it is good practice to limit levels of exposure.