Summary: All chemicals should be handled in a laboratory hood whenever possible. Chemicals that have high acute toxicity, are carcinogens, or are reproductive toxins must be handled in a laboratory fume hood (except where there is only a very low risk of exposure (e.g., use of minimal quantities in a closed system)). As a general rule, use a hood or other local ventilation device when working with any appreciably volatile substance or material easily dispersible in air (i.e., dust) having a permissible exposure limit of less than 50 ppm (or 0.25 mg/m3 for particulate matter).
|What to do?||How to do this?|
|Follow proper safety fume practices||
|For operations involving heating or volatilizing perchloric acid||Use perchloric acid fume hoods. These hoods contain water spray systems to wash down the interior of the hood, ducting, fan, and stack to prevent accumulation of explosive perchlorate crystalline material.|