ABC of Safety in the Biological Sciences

 


 

CHLOROFORM (CHCl3)

SYNONYMS
Trichloromethane, methane trichloride, methanyl trichloride, methyl trichloride, trichloroform, formyl trichloride.
CHARACTERISTICS
Clear, colourless volatile liquid with a pleasant, sweet odour. Immiscible in water but miscible with ethanol and most organic solvents. The vapour is heavier than air and will collect in hollows and confined spaces. Generally will not support combustion.
INCOMPATIBILITY
Chloroform is incompatible with:
Acetone when mixed together in a residue bottle with a base ­ explosion will occur.
Strong bases and alcohols ­ explosion hazard. e.g. Methanol and sodium hydroxide with chloroform will explode on impact.
Sodium, potassium, lithium, aluminium powder and magnesium powder ­ produces explosions ranging from violent to mild.
Potassium­sodium alloy ­ violent explosion.
Dinitrogen tetroxide ­ explosion on impact.
Fluorine ­ violent or explosive reaction.
Chloroform will attack some plastics and rubber.
In contact with water will corrode iron and certain metals.
Heating produces toxic oxides of carbon, hydrochloric acid and phosgene.
HEALTH HAZARD DATA
Chloroform is an animal carcinogen and suspected of being a human carcinogen. It is an embryotoxin and should never be handled by pregnant staff members. It is considered to be highly toxic by all exposure routes and can be readily absorbed through the skin in doses large enough to produce toxicity. It is an anaesthetic and a skin, eye and respiratory tract irritant. It affects the central nervous system. Liver and kidney damage may occur and death can result from cardiac arrest. Ingestion of alcoholic drinks will enhance the toxicity of chloroform. Persons with a pre­existing liver, kidney, skin or heart disease may be at an increased risk. Acute exposure to the skin may cause mild irritation to severe erythema and purulent blebs. Skin penetration may occur. Eye contact with liquid results in a severe burning pain, tearing and reddening of the conjunctiva. Frequently the corneal epithelium is injured and may be partially lost. The mean lethal dose when ingested is one fluid ounce. 1,000 ppm in the atmosphere is toxic and may cause dizziness, intracranial pressure and nausea. Continued exposure at this level will produce persistent fatigue and headache. 4,000 ppm will produce symptoms of vomiting, fainting and serious disorientation. 10,000 ppm will produce rapid loss of consciousness.
HANDLING and GENERAL PRECAUTIONS
Potential human carcinogen.
Highly toxic by all exposure routes.
Embryotoxin, do not allow pregnant staff to handle chloroform.
Avoid skin contact.
Avoid breathing the vapour.
Keep away from heat or naked flames. Heating produces phosgene and hydrochloric acid.
Store away from strong alkalis.
Store out of sunlight.
Keep away from incompatible substances (see text).
Ensure that chloroform is not used close to heat or a naked flame because of the possibility of producing toxic decomposition products. Use an approved fume hood that will control the level of exposure to below recommended limits. Above 500 ppm a respirator is required. Wear protective clothing. A long sleeved laboratory coat or gown, rubber gloves, safety goggles and a face mask as a minimum requirement. Rubber gloves should be manufactured from vitron or TFE. If exposure levels are going to be high then wear an approved respirator or self­contained breathing apparatus.
TREATMENTS
Skin ­ remove contaminated clothing and shoes then 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 contaminated clothing before re­use.
Eyes ­ immediately wash the affected eye with large amounts of water until all evidence of the chemical has been removed (approximately 15 minutes). Seek immediate medical advice.
Inhalation ­ remove the patient to fresh air immediately and avoid exposure to yourself. Remove contaminated clothing and loosen remaining clothing. Allow the patient to assume a comfortable position, then keep warm. Allow to rest until fully recovered. If breathing has stopped immediately apply artificial respiration. If breathing is difficult give oxygen. Seek immediate medical advice.
Ingestion ­ if the patient is conscious induce vomiting by touching a finger to the back of the throat or by administering syrup of ipecac. Avoid giving milk, oils or alcohol.
STORAGE
Store in a cool, dry, well ventilated area away from strong alkalis and incompatible substances.
DISPOSAL
WEAR:
Rubber gloves, laboratory coat and self contained breathing apparatus (or work in a fume hood).
SPILLS:
Absorb on paper towels and allow to evaporate in the fume hood. Burn the paper. Wash the spill site with a soap solution.
PACKAGE LOTS:
The toxic liquid compounds concerned here are insoluble in water and cannot be burned. purify the contaminated liquid by distillation and place the purified distillate back on the shelf.
OR
Disposal of according to any local regulations.
ENVIRONMENT

 


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