Perchloric Acid Use
Perchloric acid is clear
liquid that has no odor. Solutions below 73% at room temperature
are strong non-oxidizing acids. Perchloric acid becomes a strong
oxidizer when heated or at higher concentrations, at or above 73%.
Organic, metallic and non-organic salts formed from oxidation are
shock sensitive and pose a great fire and explosion hazard. There
are many documented accidents resulting from perchloric acid.
||Perchloric acid is destructive
to human tissue as well as very reactive. The lab should be properly
equipped and certain guidelines followed to ensure safety.
- The lab area must
be equipped with an approved emergency eyewash/shower station.
- Chemical splash and
impact rated goggles or a face shield with safety glasses, gloves
(vinyl are listed as excellent in the Lab Safety Manual) and a
- Anhydrous or concentrated
solutions of greater than 73% should not be purchased without
notifying OH&S at 7-2924.
- Standard operating
procedures (SOP) should be developed and a written copy placed
or referenced in the Lab Safety Manual. The SOP should include
engineering controls, work practice controls, necessary personal
protective equipment and emergency procedures.
- All lab personnel
shall be trained on SOPs prior to working with perchloric acid.
- Low temperature and
low concentration perchloric acid protocols should always be done
in a fume hood with no other chemicals present.
- DO NOT
perform perchloric acid digestions in a laboratory fume hood.
Any heating of perchloric acid or 73% or greater concentrations
require a special dedicated laboratory fume hood equipped with
a wash down system. Contact OH&S for more information.
and Waste disposal
||Perchloric acid stored
within the lab should be kept to a minimum.
- The maximum limit
within the lab should be kept below 450 grams (1 pound). It should
be inspected monthly and if discolored should be disposed of immediately.
- The storage of anhydrous
perchloric acid is discouraged. Storage for a short time, even
less than 10 days poses a severe risk.
- Perchloric acid should
be stored separately from many other compounds including acetic
acid, acetic anhydride, alcohols, aniline, bismuth and bismuth
alloys, combustible materials, dehydrating agents, ethyl benzene,
hydriotic acid, hydrochloric acid, grease, iodides, ketones, other
organic materials, oxidizers and pyridine.
- Perchloric acid should
be stored in its original container with its label intact and
be placed in a ceramic or plastic container large enough to contain
the entire contents. It should never be stored in a wooden cabinet
or shelves lined with paper.
- Waste should be collected
in the original container if possible and not mixed. All guidelines
within the Hazardous Waste Manual should be followed.
||Be prepared for accidents
before they occur. Ensure all emergency equipment is ready for
use, e.g. eyewashes are working and not blocked and spill kits are
- If acid comes in
contact with skin, remove clothing and wash exposed area for 15
minutes. If in eyes, they should be rinsed for at least 15 minutes
in the nearest emergency eyewash station raising upper and lower
lids periodically. While doing this, someone else should get medical
assistance by calling 7-1616 or 911.
- Any spill can be
hazardous if allowed to dry.
- Do not mop up or
soak up with a dry combustible, i.e. paper towels.
- Neutralize with sodium
bicarbonate solution and soak up with wet rags or spill pillows.
These should be kept wet and sealed in a plastic bag and Hazardous
Material Management contacted immediately.
- When cleaning up
spills chemical splash goggles or a face shield and chemical resistant
gloves must be worn. If it is a larger spill, coveralls and protective
shoe covers might be needed.
||The following links
will provide more information on this topic.