Every enclosed workplace must be ventilated by a sufficient quantity of fresh or purified air. The requirements cover the workplace in general with the aim of ensuring that: - stale air, and air which may be humid or hot, is replaced at a reasonable rate (as a guide, the supply rate for fresh or purified air should not fall below 5 - 8 litres per second per occupant); - the air that is introduced should, as far as possible, be free of any impurity which is likely to be offensive or cause ill health.
Plant used in ventilation (including air conditioning systems) must, where necessary for health or safety reasons, include an effective device to give visible or audible warning of plant failure. Moreover, ventilation plant should be properly maintained and be kept free from anything which may contaminate the air.
In many premises, windows and other openings will provide sufficient ventilation in some or all parts of the workplace. Where such openings provide inadequate ventilation, mechanical ventilation systems should be provided. In all cases, workers should not be exposed to uncomfortable draughts. Thus, the direction and speed of air flow may need to be controlled, or workstations may need to be re-sited or screened.
Exposure To Poor Ventilation
In certain cases, for example in workplaces where humid air is necessary for the business (such as in mushroom growing) the requirements cannot be fully met and so workers should be allowed adequate breaks in a well-ventilated place.
The only exceptions to these requirements are confined spaces where breathing apparatus may be necessary. Moreover, the requirements do not cover local exhaust ventilation for controlling exposure to potentially hazardous substances.