2.1.1 Heating Perchloric Acid
DO NOT use heated Perchloric acid in a regular fume hood. If heated Perchloric acid is used in a regular fume hood (without a wash down function), shock sensitive metallic perchlorate crystals can form inside the duct work, and could result in causing an explosion during maintenance work on the ventilation system. Use of heated Perchloric acid requires a special perchloric acid fume hood with a wash down function. If you suspect your fume hood has perchlorate contamination or would like more information on perchloric acid fume hoods, then contact askEHS.
Laboratory groups who use these hoods shall document standard procedures for the frequency and length of running the washdown system. In some cases, this may be with every use. This procedure shall also include how often a complete cleaning of the hood surfaces is required in order to ensure that dust and splatter on the inside of the hood, that may contain perchlorate salts, do not build up.