The Health and Safety at Work Act 1974 (HSWA) extend to risks from legionella bacteria which may arise from work activities. This Act lays down that employers or persons concerned with the premises owe the 'common duty of care' both to employees and others who may use or visit the premises. The condition of premises shall be treated as a risk attributable to the manner of conducting the undertaking.

The Health and Safety at Work Regulations 1999 (MHSWR) provide a broad framework for controlling health and safety at work. As well as requiring risk assessments, they also require employers to have access to competent help in applying the provisions of health and safety law; to establish procedures to be followed by any worker if situations presenting serious and imminent danger were to arise; and for co-operation and co-ordination where two or more employers or self-employed persons share a workplace.

COSHH (Control of Substances Hazardous to Health) Regulations provide a framework of actions designed to control the risk from a range of hazardous substances including biological agents. The COSHH requires the employer to make a formal assessment of health risks from hazardous substances, which include human pathogens. Regulation 7(1) requires the employer to prevent exposure of his employees to substances hazardous to health, or where this is not reasonably practical, to ensure they are adequately controlled. In brief, the essential elements of COSHH are: risk assessment; prevention of exposure or substitution with less hazardous substances if this is possible, or substitution of a process or method with a less hazardous one; control of exposure where prevention or substitution is not reasonably practical; maintenance, examination and testing of control measures, e.g. automatic dosing equipment for delivery of biocides and other treatment chemicals; provision of information, instruction and training for employees; and health surveillance of employees.

The Approved Code of Practice (ACOP) for 'The control of legionella bacteria in water systems' (L8) was launched on January 8th 2001 and replaced two separate documents: the 1995 Approved Code of Practice and the associated HS(G)70. This ACOP applies to the control of legionella bacteria in any undertaking involving a work activity and to premises controlled in connection with a trade, business or other undertaking where water is used or stored and where there is means of creating and transmitting water droplets which may be inhaled, thereby causing a reasonably foreseeable risk of exposure to legionella bacteria. Enforceable under the COSHH Regulations and HSWA 1974. To comply with their legal duties, employers and those with responsibilities for the control of premises must: Identify and assess sources of risk by implementing a legionellosis risk assessment. Prepare a scheme for preventing or controlling the risk. Implement, manage and monitor precautions. Keep records of the precautions taken. Appoint a person to be managerially responsible. This Code has a special legal status. If you follow the advice you will be doing enough to comply with the law in respect of those specific matters on which the Code gives advice. You may use alternative methods to those set out in the Code in order to comply with the law. However, this Code has a special legal status. If you are prosecuted for breach of health and safety law, and it is proved that you did not follow the relevant provisions of the Code, you will need to show that you have complied with the law in some other way or a Court will find you at fault. Health and safety inspectors seek to secure compliance with the law and may refer to this guidance as illustrating good practice.

Workplace (Health, Safety and Welfare) Regulations 1992, the Health & Safety Commissions Approved Code of Practice and Guidance L24. Enforceable under the COSHH Regulations 1994 and The Health and Safety at Work Act 1974. "This code has been approved by the Health & Safety Commission and gives advice on how to comply with the law. This code also has a special legal status.

The Control of Legionellae in Health Care Premises. This Code of Practice gives day to day guidance on the management of hot and cold water systems and other systems where there is a risk of proliferation of legionella bacteria. It also deals with engineering and design aspects of these systems.

The Water Supply (Water Fittings) Regulations 1999 (Model Water Byelaws). These regulations replaced the Model Water Byelaws and came into effect on July 1st 1999. They are enforceable under sections 74, 84 and 213(2) of the Water Industry Act 1991 for preventing waste, undue consumption, misuse or contamination of water. It is the responsibility of anyone installing or improving a plumbing system to ensure that they comply with the Regulations.

The Occupiers Liability Act 1984. This Act imposes a duty of care on the occupier of the premises to prevent risk to others of injury, which includes any disease or impairment of physical or mental condition. BS 6700: 1997. Specification for the design, installation, testing and maintenance of services supplying water for domestic use within buildings and their curtilages. In addition to these, there are several other guidance documents for the control of legionella bacteria and other organisms in water and air systems. Some are specific to health care premises, spa pools and cooling towers etc. For further information please refer to page 60 of the ACOP for 'the control of legionella bacteria in water systems (L8)'.

BS 6700 British Standard Specification for the design, installation, testing and maintenance of services supplying water for domestic use within buildings and their curtilages.

CIBSE (Chartered Institute of Building Services Engineers) guidance documentation on the control of legionella bacteria in water systems.

NB - This is by no means an exhaustive list of legislation and guidance but is intended purely as a guide to the most relevant documentation.