ABC of Safety in the Biological Sciences
FORMALIN (40% formaldehyde solution) (HCHO)
SYNONYMS
Formic aldehyde (formol methanol), methyl aldehyde, methylene
glycol, methylene oxide, tetraoxymethylene, oxomethane,
oxymethylene, methanal, aldehyde formique.
CHARACTERISTICS
Colourless liquid with a pungent, irritating odour. The vapour
threshold is one part per million. There is a moderate fire
hazard when formalin is exposed to heat or a naked flame.
INCOMPATIBILITY
Formaldehyde is incompatible with:
Nitrogen dioxide explosive reaction at 180°C.
Hydrogen peroxide violent reaction.
Hydrochloric acid forms highly toxic chloromethyl ether.
Strong oxidising agents violent reaction.
Nitromethane forms explosive compound.
Peroxyformic acid forms explosive compound.
Magnesium carbonate explosive reaction.
Heating a sealed container may explode.
Heating produces toxic oxides of carbon.
HEALTH HAZARD DATA
Formalin is a proven animal carcinogen, produces squamous cell
carcinomas in the nasal cavities, and is believed to be the same
in humans. It is a strong eye, mucous membrane and skin
irritant. It is also a skin and respiratory sensitiser. Death
has been reported in workers exposed to high levels of formalin
vapour. Acute exposure to the eyes by the vapour causes profuse
lacrimation and can cause eye damage. Liquid splashes to the eye
can cause burns, severe injury and corneal damage. Skin contact
may cause irritation and sensitisation dermatitis may occur in
previously exposed workers. This can take a very serious course.
Inhalation of concentrations as low as 1 ppm may cause mucous
membrane and respiratory tract irritation with tearing and a
mild tingling sensation in the nose and throat. High
concentrations may cause cough, headache, nausea, weakness,
palpitation, dyspnoea, burning of the nose and throat,
bronchitis, pulmonary oedema, pneumonitis and death. Ingestion
may cause burning in the mouth and oesophagus, nausea, vomiting,
severe abdominal pain, diarrhoea, vertigo, anuria,
unconsciousness, jaundice, albuminuria, haematuria, acidosis,
and convulsions. Liver and kidney damage may occur. Death occurs
from circulatory failure. A mean fatal dose is approximately 2
ounces of a 40% solution.
HANDLING and GENERAL PRECAUTIONS
Potential carcinogen.
Highly toxic.
Use a fume hood.
Avoid skin contact.
Avoid inhalation of the vapour.
Keep away from heat or naked flames.
Vapour air mixtures are explosive above 54°C.
Use an approved fume hood that will keep levels of exposure
below the recommended limit, i.e. one part per million. For
exposure above this level a respirator is recommended. Above 30
ppm a selfcontained breathing apparatus is recommended. Wear
protective clothing. A long sleeved laboratory coat or gown,
rubber gloves and full face protection as a minimum standard.
TREATMENTS
Skin remove contaminated clothing and shoes immediately. Wash
the affected area with soap or mild detergent and large amounts
of water until all evidence of the chemical has been removed
(approximately 15 minutes). Seek medical advice. Wash clothes
thoroughly before reuse.
Eyes wash the affected eye immediately with large amounts of
water until all evidence of the chemical has been removed
(approximately 15 minutes). Seek immediate medical advice.
Inhalation immediately remove the patient to fresh air, avoid
inhalation of the vapours yourself. If breathing has ceased
apply artificial respiration. Keep warm and allow to rest. Seek
immediate medical attention.
Ingestion if the victim is conscious and not convulsive,
immediately give two to four glasses of water and induce
vomiting by touching a finger to the back of the throat. Place
in a sitting position and bring the head forward to be lower
than the hips. Keep the patient warm and allow to rest. Seek
immediate medical attention.
STORAGE
Store in a cool, dry, well ventilated room away from heat or
naked flame. Do not store close to strong oxidising agents.
DISPOSAL
WEAR:
Rubber gloves, self contained breathing apparatus and laboratory
coat.
SPILLS:
Eliminate all sources of ignition and flammables.
Small: absorb on a paper towel. Evaporate in fume hood and burn
the paper.
Large: cover with sodium bisulphite. Add a small amount of water
and mix. Scoop into a large beaker. Discharge to sewer with a
large excess of water. Wash the spill site with a soapy
solution.
PACKAGE LOTS: Either
1 Absorb on vermiculite. Burn in an open pit or open
incinerator.
2 Dissolve in a flammable solvent (such as acetone or benzene).
Spray into the fire box of an incinerator equipped with an
afterburner.
ENVIRONMENT
Formalin is harmful to aquatic life.
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