Ventilation Flashcards
Is adequate ventilation provided by natural or mechanical means to prevent concentrations of vapour accumulating to within the relevant explosive limits of the most hazardous solvent likely to be present?
Adequate ventilation should be provided by natural or mechanical means to prevent the concentration of vapour accumulating to within the relevant explosive limits of the most hazardous solvent likely to be present. The degree of ventilation required will depend on the flashpoint of the liquid, the quantities in use, the location of the work and the type of process and will normally be determined by reference to the COSHH assessment (see ref 15).
Are flammable liquid stores located at or above ground level unless sufficient mechanical ventilation is provided?
Flammable liquid stores should be at or above ground level unless sufficient
mechanical ventilation is provided.
Are adequate ventilation openings provided at low and high level, direct from the storage area to the outside to prevent accumulations of flammable vapour?
Ventilation openings should be provided at low and high level, direct from the storage area to the outside, to prevent the accumulation of flammable vapour. Care should be taken to prevent drums and other items from obstructing the openings. Natural ventilation may be achieved by the use of air-bricks.
If mechanical ventilation is used, does it provide at least six air changes per hour with extract at low level and inlets at high level, positioned so as to provide cross-flow?
Mechanical ventilation may be used, providing at least six air changes per hour.
Extract must be at low level and the inlet at high level, positioned so as to provide cross-flow. Duct openings should not allow fire spread. Fan motors should not be positioned within ductwork, and should be suitable for the hazard zone. All mechanical ventilation installations shall comply with BS 5925 (ref 28).
Where mechanical ventilation is installed, is the location of the exhaust outlet subject to a risk assessment in compliance with DSEAR?
Where mechanical ventilation is installed the location of the exhaust outlet should be subject to a risk assessment in compliance with DSEAR. In most cases it should be adequate if the ventilation ductwork is terminated at least 3m above ground level and the same distance from building openings (including the eaves of buildings), boundaries, natural hazards such as drains and sources of ignition
Is ducting of non-combustible construction, taking as short a route as possible, with as few directional changes as possible and arranged so that vapours cannot condense and collect at low points in the ductwork?
Ducting should:
- be of non-combustible construction;
- take as short a route as possible;
- have as few directional changes as possible;
- be arranged so that vapours cannot condense and collect at low points in the
ductwork; and - be routed to a safe place in the open air
Is ductwork for extracting flammable vapours free of dampers?
No fire dampers should be fitted in extract ducts for flammable vapours.
Where flammable or highly flammable liquids are stored and mechanical ventilation cannot be provided, is explosion relief provided according to the findings of a risk assessment?
Where flammable or highly flammable liquids are stored and mechanical ventilation cannot be provided, explosion relief should be provided according to the findings of a risk assessment. In such a case, a lightweight roof or relief panels in the walls would serve to vent an explosion, provided that they release the pressure to a safe place so as not to cause injury or damage to property.
Is expert advice sought if necessary where the discharge of a dangerous substance into the atmosphere may have an environmental impact?
The discharge of a dangerous substance into the atmosphere may have an
environmental impact and thus expert advice should be sought where necessary
Are safe procedures followed for the cleaning of tanks and vessels, particularly where a change of use or type of content is proposed?
Safe procedures must be followed for the cleaning of tanks and vessels, particularly where a change of use or type of content is proposed (see HSE Guidance Note CS15, ref 29).
