Air quality must be assessed/or substantial quantities of hazardous substances including human diseases and dust. Employers must ensure that employees are not exposed to such risks and that such hazards are adequately controlled.

- COSHH (Control of Substances Hazardous to Health) Regulations Statutory Instrument No 3246, 1994.

Mechanical Ventilation Systems (including air conditioning systems) should be regularly and properly cleaned, tested and maintained to ensure that they are kept clean and free from anything which may contaminate the air.

- Health and Safety Commision's Approve Code of Practice as incorporated by the Workplace (Health, Safety and Welfare) Regulations 1992

Anyone in control of premises (employers, landlords, tennants etc) must display a common duty of care to both employees and anyone else using their premises.

- The Health and Safety at Work Act 1974.

Such duty extends to preventing risk of injury to others, including any disease and impairment of physical or mental condition.

- The Occupiers Liability Act 1984

All furniture, furnishings and fitting in premises shall be kept in a clean state.

- Section 4, The Offices, Shops and Railway Premises Act 1963.