ABC of Safety in the Biological Sciences
HYDROFLUORIC ACID (HF)
SYNONYMS
Fluoric acid.
GENERAL PRECAUTIONS
Very hazardous substance, handle with extreme care. Use a fume
hood.
Wear protective clothing at all times.
Avoid skin and eye contact.
Avoid inhalation.
CHARACTERISTICS
Clear, colourless liquid with a highly corrosive, irritating,
white vapour.
HEALTH HAZARD DATA
A liquid which gives off acrid fumes. Both the liquid and the
vapour are extremely corrosive and toxic. Exposure to high
concentrations can be fatal. Injuries from dilute acid and
vapour may not become apparent for several hours. Concentrations
of 10ppm are intolerable to breath. 25ppm can produce severe
injuries with 50ppm causing death. Acute eye exposure is
severely irritating, a splash causing severe burns with
blindness resulting if treatment is not rapid. Skin contact
causes severe burns and it is rapidly absorbed through the skin.
Pain may not be immediate with dilute solutions. Inhalation is
extremely irritating to the respiratory tract and high exposure
can be fatal. Ingestion causes severe irritation and burning
with damage to the mouth, oesophagus and stomach.
TREATMENTS Skin immediately drench with large amounts of
water, do not wait to remove clothing but remove under the
safety shower. Wash until all evidence of the chemical has been
removed (approximately 15 minutes). Massage calcium gluconate
gel into affected parts until pain subsides, then seek immediate
medical attention. Calcium gluconate is available from any
pharmaceutical outlet and should be part of your laboratory
first aid kit if hydrofluoric acid is handled in your
laboratory.
Eyes immediately wash the affected eye with large amounts of
water until all evidence of the chemical has been removed, then
apply calcium gluconate eye drops. Seek immediate medical
attention. Calcium gluconate eye drops are available from any
pharmaceutical outlet and should be part of your laboratory
first aid kit if hydrofluoric acid is handled in your
laboratory.
Inhalation remove from the area of exposure to fresh air. If
breathing has ceased apply artificial respiration. If breathing
is laboured give oxygen. Seek immediate medical attention.
Ingestion wash the mouth with water and give milk and give
milk of magnesia or milk to drink. Do not induce vomiting. Seek
immediate medical attention.
INCOMPATIBILITY
Hydrofluoric acid is incompatible with all materials containing
silica and will react vigorously with neutralising agents.
Heating produces toxic fumes of fluorine.
STORAGE
Store in a cool, dry, well ventilated area that is secure.
HANDLING
Use a fume hood that will keep levels of exposure below the
recommended threshold, ie. 3ppm. If exposure is expected to
exceed this level then a respiratory is recommended.
Concentrations above 10ppm are intolerable to breath, a
selfcontained breathing apparatus is recommended. Wear
protective clothing. A long sleeved laboratory coat or gown,
rubber gloves (PVC), a full face shield plus safety goggles and
a face mask as a minimum standard. In addition a PVC apron,
leggings and boots will provide added protection.
DISPOSAL
WEAR:
Rubber gloves, laboratory coat and self contained breathing
apparatus. have a body shield available.
SPILLS:
Cover the contaminated surface with sodium bicarbonate or soda
ash-slaked lime mixture (50/50). Mix, and add water if necessary
to form a slurry. scoop up the slurry and discharge to the sewer
with a large excess of water.. wash the spill site with a soda
ash solution.
PACKAGE LOTS:
Add slowly to a large volume of an agitated solution of soda ash
and slaked lime until the solution is neutral. Discharge to the
sewer with a large excess of water.
ENVIRONMENT:
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