HSG274 Part new HSE legionella guidance now issued

11th April 2014

HSE have issued this new guidance this month and we are now supporting its implementation with our customers. If you would like more information or help to see if you are compliant please call

  1. HSG274 Part 2, the guidance covering hot and cold water systems has now increased significantly from 15 to 58 pages... a big increase by any standards.

  2. All risk assessments should now consider both the relative risks associated with legionella bacteria and scalding from hot water.

  3. There is now significantly more information covering water system engineering design, including:

    • Calorifiers attached to solar heating systems.
    • Expansion vessels.
    • Point of use water heaters and combination water heaters.
    • Clarification on what is a “sentinel” outlet on large multi-loop systems.
    • There is also a simple definition of a low risk system.
  4. New Section: “Residential accommodation: Landlords and shared premises”. This new section gives guidance on how to risk assess and control both domestic and commercial tenanted properties. It is essential that property owners, landlords and tenants understand this new section.

  5. New Section: “Special considerations for healthcare and care homes”. The guidance gives new information on those special considerations where there are susceptible individuals, including revised guidance on acceptable levels of legionella bacteria in water systems.

  6. Commissioning of new buildings has in the past resulted in significant legionella growth. There is now a significant section devoted to this topic which includes guidance when “mothballing” water systems for times of non-use. This is an important area for builders, developers and other owners of property and one that needs careful consideration.

  7. Potential problems are highlighted for hot water systems with secondary and tertiary loops; systems that are prevalent in hospitals and healthcare facilities. The guidance also introduces new recommended requirements for routine monitoring.

  8. New routine monitoring recommendations are now included, including point of use heaters, combination heaters, TMV’s and others.

  9. Significantly increased section on the use and control of chemical water treatments and biocide systems.

  10. Appendices included in the new guidance define much broader requirements for the risk assessment and written control scheme including the need for incident planning.