Document ID: chunk:federal_register_of_legislation:F2016L00420:front:0:p30
Version: federal_register_of_legislation:F2016L00420
Segment Type: other
Provision Reference: 
Character Range: 79650–82637

the area of contamination in the event of spills and leaks. They often involve partial enclosure, use of exhaust ventilation or automation of processes. Examples of engineering controls include:
    * using intrinsically safe electrical equipment in hazardous areas
    * using robots to minimise operator exposure, for example, spraying in coating operations
    * partially enclosed and ventilated spray booths or fume cupboards
    * fully enclosed ventilation booth (see diagram 1)
    * local exhaust ventilation to capture airborne contaminants close to their point of release (see diagrams 2 and 3).
Local exhaust ventilation is designed to capture airborne contaminants close to the source of generation. This prevents them contaminating the working environment. The ventilation should be arranged to prevent contaminants from entering the breathing zone of the operator. The exhaust extraction shown in diagram 4 is a well-designed system, while that shown in diagram 5 is poorly designed as it carries contaminants directly through a person's breathing zone.

Design considerations for ventilation systems
Ventilation is a means of maintaining a safe atmosphere by the introduction or recirculation of air; by natural, forced or mechanical means. Maintaining a safe atmosphere in the storage and handling area of hazardous chemicals is an important control measure. Recirculation should be avoided unless precautions are taken to detect and avoid harmful contamination, and prevent accumulation of airborne contaminants. Recirculation should only be used where temperature control is required.
A ventilation system should operate exclusively for the particular building, room or space.
Where this is not practicable, the system may be linked to another area provided that this does
not increase the risk to exposure of hazardous chemicals, for example by recirculating hazardous or flammable vapours or spreading them into other areas where that chemical is not being used.
Ventilation systems should be suitable for the types of hazardous chemicals on the premises.
For example, if a hazardous chemical has vapours which are denser than air, these will accumulate in low lying areas. In this case, extraction of vapours should be from the lowest point and fresh air introduced from above.

Exhaust systems and ducting should be resistant to the vapours, mists or dusts being extracted. The risk of fire propagation can be reduced by installing self-closing fire dampers, for example in laboratory fume cupboards. Extraction ducting should not be linked to multiple items of plant if there is any risk of fire spreading through the ducting. Provision against flashback, for example
by installing flame arresters, may be necessary.

Exhaust gases and air should be discharged where it will not cause other hazards. For example, fume cupboard extraction systems should not exhaust close to air intakes and should be in compliance with any local building or environment protection