XIII. |
Working With Perchloric Acid
Perchloric Acid
Concentrated perchloric acid (>72%) is a powerful oxidizer
and can produce potentially explosive compounds when reacted
with many different materials including transition metals,
reducing agents, organic compounds, etc.
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A. |
Concentrated perchloric acid must not be handled
in a regular laboratory hood. The use of "fume eradicators"
or similar vapor-capturing devices are recommended when heating
concentrated perchloric acid. |
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B. |
Storage
Perchloric acid must be stored separately from all materials
except nitric acid. Perchloric acid must not be stored near
heat sources. As with all acids, secondary containment must
be compatible with the material stored. Secondary containment
made of glass, ceramic, or porcelain is recommended.
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C. |
Spills
If perchloric acid is spilled, immediately dilute the area
with water. Special precautions should be taken if the spill
comes in contact with organic material (paper, wood, etc.)
as these materials are readily oxidized. Ignition is likely
if contaminated materials are subjected to heat or spark.
If the spill contaminates organic materials, the material
should be tested for perchlorates prior to disposal. If the
test reflects that perchlorates are present, continue to rinse
the material with water until testing results in a negative
reading.
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D. |
Testing for Perchlorates
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- Collect a 10-20 ml sample of wash water flushed
from a surface or material contaminated with perchloric acid. |
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- Add 2-5 drops of a 0.1% solution of methylene blue
in water. |
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- A violet precipitate indicates that perchlorates
are present. |
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- The material or surfaces must be flushed until the
water tests are negative. The waste water may be disposed of
via the sanitary sewer system if the pH is greater than 2. |
