Legionella & Pseudomonas risk assessments and control

Assess and control the risks from water borne infections in your facilities

Failures in the design, operation, maintenance or monitoring of man-made water systems can allow bacteria to thrive. The law requires the duty holder in any healthcare establishment to assess the health risks posed to its water supply. They must appoint competent persons to conduct this assessment to take responsibility for an appropriate risk control scheme and to keep detailed records. The risk assessment should include a clear allocation of management responsibilities, evidence of the competence and training of key personnel, a description of the water system (including a schematic diagram) and procedures for the operation, monitoring, inspection and maintenance of the system. The assessment must be updated regularly, especially if the design or use of the system changes.

  • Keep on top of changes in regulations and your responsibilities
  • Identify and understand the water-born infection risk in your organisation
  • Implement systems to manage the risks and provide protection

What are Legionella and Pseudomonas?

Legionella bacteria can cause Legionnaires’ disease, a difficult-to-treat form of pneumonia if inhaled in water droplets. Pseudomonas aeruginosa, another category of a pathogen, can infect almost any part of the body from the skin to the central nervous system. The threat from these organisms is very real. Between 3,700 and 4,000 P. aeruginosa infections are reported to the Health Protection Agency every year, and the fatality rate for hospital-acquired Legionnaires’ disease is close to 50% The UK has strong regulatory frameworks governing the design and operation of water supply systems. The HSE document Legionnaires’ disease: The control of legionella in water systems is the approved code of practice in the UK. While Legionella bacteria enter the water system of a building from the external supply, Pseudomonas aeruginosa is far more opportunistic. It can survive away from a water source for several hours and can enter water systems via outlets within the building, such as taps and shower heads, and colonise the pipework close to these fittings.

On-going risk management should include regular sampling of water at all outlets within a facility. Where Pseudomonas aeruginosa contamination is detected, remediation actions include the removal of items like flow straighteners, or flexible connectors that can provide a habitat for bacterial growth, together with measures to reduce the splashing that can lead to contamination of outlets in use. In some circumstances, it may be necessary to carry out a disinfection of the water supply system. Modern high-performance biocides, such as our Ultralox 40 active chlorine solution, have been shown to give very effective results against both Legionella and Pseudomonas aeruginosa, combined with a low hazard classification and good environmental profile.


  • Understand your responsibilities under Approved Code of Practice L8
  • Identify responsible persons in your organisation
  • Get advice on guidelines for your water systems

Legionella and Pseudomonas risk assessments

  • Understand why a risk assessment is necessary
  • Discover what a risk assessment involves
  • Get a qualifed risk assessment for your facilities

Accreditations and learning materials

  • Learn about our expertise in Legionella & Pseudomonas control
  • Access free training and learning materials
  • Keep on top of regulations and best practice guidelines

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