ABC of Safety in the Biological Sciences



FORMALIN (40% formaldehyde solution) (HCHO)

Formic aldehyde (formol methanol), methyl aldehyde, methylene glycol, methylene oxide, tetraoxymethylene, oxomethane, oxymethylene, methanal, aldehyde formique.
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.
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.
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.
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.
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.
Store in a cool, dry, well ventilated room away from heat or naked flame. Do not store close to strong oxidising agents.
Rubber gloves, self contained breathing apparatus and laboratory coat.
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.
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.
Formalin is harmful to aquatic life.


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