Are you responsible for testing water systems for bacteria?
Do you need help with preventing Legionnaires’ disease?
Legionnaires’ disease was first recognised in July 1976 and since then over 50 other species of legionella have been described of which at least 20 have been associated with disease in humans. The numbers of reports of Legionnaires’ disease continues to rise. This is probably due to an increased recognition of the disease using improved diagnostic and a greater exposure to potential sources.
The disease is not known to be transmissible via person-to-person contact. As a result, the way to prevent or control outbreaks of Legionnaires’ disease is to inhibit or limit the growth of these organisms in water. To demonstrate that measures to control legionellae are effective there is an increasing need to sample potential sources for the presence of legionellae.
In the UK, outbreaks of Legionnaires’ disease have been commonly associated with:
- Evaporative cooling towers and condensers
- Hot and cold water systems in large buildings, such as hospitals and hotels
- Spa pools
- Nebulizers or other medical respiratory equipment (usually by filling or washing such items with tap water containing the bacteria)
- Household plumbing systems.
BS 7592 gives recommendations and guidance on the sampling of water and related materials. It involves testing for the presence of legionella. It applies to sampling artificial water systems and gives methods for sampling of biofilms and sediments that might be present in water systems. Some of the same sampling methods can also be applied to natural water systems.
BS 7592 is for both sampling for routine monitoring and in outbreak investigations. For outbreak investigations recommendations and guidance on the selection of sampling points are given.
BS 7592 is a key standard for all those involved in water sampling for legionellae including those taking samples on site and their employers.
The revised version of BS 7592 replaces the 2002 edition and:
- Makes a clearer distinction between routine and incident sampling
- Provides a clearer rationale for routine sampling, including newly-recognised sources, risk assessment, surveying and sample points
- Revises acceptable transport times, to account for more quantitative results and sampling / transport subcontracting
- Takes account of new standards documents for water sampling and analysis
Contents:
Foreword
Introduction
Section 1: General
Scope
Normative references
Terms and definitions
Risk assessments
Safety of sampling personnel
Survey and sampling
Apparatus and materials
Section 2: Routine sampling
Sampling procedures
Sample transport and storage
Section 3: Sampling for outbreak and other investigations
General
Safety of sampling personnel
Apparatus and materials
Sampling procedures
Other sources
Annexes
Annex A (informative) Label and sample collection form information
Bibliography
