Appendix O

Perchloric Acid

Perchloric acid is a strong oxidizing acid that can react violently with organic materials. Perchloric acid can also explode if concentrated above 72%.

  • For any work involving heated Perchloric Acid (such as in Perchloric Acid digestions), the work must be conducted in a special Perchloric Acid fume hood with a wash down function. If heated Perchloric Acid is used in a standard fume hood, the hot Perchloric Acid vapors can react with the metal in the hood ductwork to form shock sensitive metallic perchlorates.

    As of September 2008, there are no approved Perchloric Acid hoods on campus.
  • Due to the potential danger of Perchloric Acid, if possible, try to use alternate techniques that do not involve the use of Perchloric Acid. If you must use Perchloric Acid in your experiments, only purchase the smallest size container necessary.
  • Because Perchloric Acid is so reactive, it is also important to keep it stored separate from other chemicals, particularly organic solvents, organic acids, and oxidizers.
  • Like all acids, but particularly with Perchloric Acid, secondary containment should be used for storage.
  • All containers of Perchloric Acid should be inspected regularly for container integrity and the acid should be checked for discoloration. Discolored Perchloric Acid should be discarded as hazardous waste.
  • When working with Perchloric Acid, be sure to remove all organic materials, such as solvents, from the immediate work area.
  • Oxidizable substances must never be allowed to contact Perchloric Acid. This includes wooden bench tops or hood enclosures, which may become highly flammable after absorbing Perchloric Acid liquid or vapors, Beaker tongs, rather than rubber gloves, should be used when handling fuming Perchloric Acid.