STUDENT SAFETY SHEETS
62
Chlorinated hydrocarbons
Substance
Dichloromethane
(Methylene dichloride)
Hazard
Comment
H
It is harmful if breathed in, with a possible risk of effects which
cannot be reversed, eg, liver damage. Breathing high concentrations causes headaches. It degreases the skin. There is limited
evidence of a carcinogenic effect. It is used in some paint strippers.
HARMFUL
Trichloromethane
(Chloroform)
H
HARMFUL
Tetrachloromethane
(Carbon tetrachloride)
T
TOXIC
N
DANGEROUS FOR
THE ENVIRONMENT
1,1,1-trichloroethane
(Methyl chloroform)
and Tetrachloroethene
(Tetrachloroethylene)
H
HARMFUL
N
DANGEROUS FOR
THE ENVIRONMENT
Trichloroethene
(Trichloroethylene)
T
TOXIC
It is harmful, with a danger of serious damage to health by
prolonged exposure through inhalation and if swallowed. There is
limited evidence of a carcinogenic effect. It is irritating to the skin.
It has been used as an anaesthetic.
It is toxic if swallowed, from skin contact and if breathed in, with
the danger of serious damage to health by prolonged exposure
through inhalation. There is limited evidence of a carcinogenic
effect. It damages the ozone layer and is harmful to aquatic organisms in the environment. It can no longer be legally bought and
existing stocks should not be used in work with open test tubes.
1,1,1-trichloroethane is harmful if breathed in. It damages the
ozone layer. It damages the ozone layer. It can no longer be legally
bought and existing stocks should not be used in work with open
test tubes.
There is limited evidence that tetrachloroethene is a carcinogen. It
is toxic to aquatic organisms in the environment. It is used in dry
cleaning.
It may cause cancer with possible risk of effects which cannot be
reversed. It is irritating to the eyes & skin and its vapour may
cause drowsiness and dizziness. It was used in dry cleaning but
has been replaced by tetrachloroethene.
Typical control measures to reduce risk
•
•
•
Use the smallest volume possible and wear suitable eye protection.
Use a fume cupboard for anything larger than test-tube amounts; ensure good laboratory ventilation.
When choosing a solvent, pick the safest one with suitable properties - cyclohexane, Volasils or Lotoxane are
safer than chlorinated hydrocarbons and usually work satisfactorily.
Assessing the risks
•
•
•
•
What are the details of the activity to be undertaken? What are the hazards?
What is the chance of something going wrong?
How serious would it be if something did go wrong?
How can the risk(s) be controlled for this activity?
Eg, Can it be done safely? Does the procedure need to be altered? Should goggles or safety spectacles be worn?
Emergency action
•
•
•
In the eye
Vapour breathed in
Swallowed
•
Spilt on the skin or
clothing
Spilt on the floor,
bench, etc
•
Flood the eye with gently-running tap water for at least 10 minutes. See a doctor.
Remove the casualty to fresh air. Call a doctor if more than a ‘sniff’ is breathed in.
Do no more than wash out the mouth with water. Do not induce vomiting. Sips of water
may help cool the throat and help keep the airway open. See a doctor.
Remove contaminated clothing. Wash the skin with soap and water. Take contaminated
clothing outside for the solvent to evaporate.
Open windows if large amounts are spilt. Consider the need to evacuate the laboratory
for large spills of the more-hazardous solvents. Cover with mineral absorbent (eg, cat
litter) and scoop into a bucket. Add washing-up liquid and work into an emulsion. Wash
to waste with plenty of water.
© CLEAPSS 2007