EliminationSubstitution Isolation Segregation Engineering Controls - Ventilation

88 Elimination Substitution Isolation Segragation Engineering Controls Including LEV Administrative Controls Personal Protective Equipment In c re a s in g p re fe re n c e Source: Adrian Hirst

9.1.1 EliminationSubstitution

The most effective form of prevention control is simply to either eliminate the use of the hazardous agent, or the actual process in which it is used. This is clearly not often practicable, but quite commonly hazardous agents or processes can be substituted with relatively innocuous ones, e.g.  Benzene replaced with toluene.  Carbon tetrachloride replaced with methyl chloroform.  Talc replaced with chalk.  Sand blasting replaced by steel shot blasting.  Dry handling techniques replaced by wet handling techniques. i.e. suppression of dust emission e.g. removal of asbestos lagging.

9.1.2 Isolation

Wherever possible processes or operations, which involve some risks to health, should be completely enclosed, with the operators outside the enclosure.

9.1.3 Segregation

Hazardous processes or operations etc. can be segregated from lower risk ones by placing them, for example, at the far end of a workshop, in a separate 89 room, or in a separate building, thereby minimising the number of workers at risk.

9.1.4 Engineering Controls - Ventilation

Processes capable of producing exposures to hazardous substances only, are commonly controlled by the provision of mechanical air handling methods, of either one of the two types below or a combination of both. Local Exhaust Ventilation LEV Local Exhaust Ventilation LEV - application of mechanical air handling techniques whereby potential airborne contaminants are captured near to the source of emission, extracted, and discharged to either a safe location or subjected to some form of „air cleaning‟ technique. It is particularly valuable for situations that involve a point source release of toxic contaminants. General Dilution Ventilation Dilution Ventilation - this is widely used throughout industry for the ventilation of control rooms, photographic laboratories, office spaces, mess-rooms and printing rooms. It is not normally suitable for the control of dust, mist of fume or for substances of moderate to high toxicity, or in situations where the rate of generation of contamination is non-uniform or high. Heating, Ventilation and Air Conditioning HVAC can also be used in a variety of ways to control hazards associated with the thermal environment.

9.1.5 Administrative Controls