Clutter in the hood disrupts the air flow, reducing its capture efficiency. Avoid sudden movements while working in the hood. Walking briskly past the hood can disrupt air currents and pull vapors out of the hood. Keep your head outside of the fume hood, but set equipment and perform task as far back in the hood as possible. Perchloric acid can leave explosive residues in a fume hood, duct system, or on a hood fan.
Perchloric acid can also form explosive mixtures with organic compounds.
For this reason, the use of perchloric acid in fume hoods must be carefully evaluated prior to use. This should be drawn in when the hood is operating normally, and will hang straight down when the hood is operating marginally, or not at all. Always check your chemical fume hood flow indicator. If air flow has ceased, quickly close the sash and immediately call Facilities Services Service Request Center 752-1655 to arrange for repairs. When highly toxic substances must be contained, or reactive substances must be handled in an inert or dry atmosphere, it may be necessary to use a completely enclosed glove box unit.