Legionella – Controlling the risks

Two recent criminal prosecutions against NHS trusts highlight the importance of ensuring that proper control measures are put in place to protect people from being exposed to the legionella bacteria, says Matthew Taylor.

16 July 2015 | By Matthew Taylor

The case – on 11 June 2015, Brighton and Sussex University Hospital NHS Trust was fined £50,000 and ordered to pay £38,705.60 in costs for failing to control legionella at its hospital. Cancer patient Joan Rayment, 78, had contracted an infection while being treated in hospital. An inquest found that the legionella had been appropriately treated, however, it was found that the infection could have hastened her death.

The court was told that although the trust was monitoring legionella and water temperatures across its various sites, a total of 114 positive legionella tests and a further 651 records of water temperatures outside the required parameters were not adequately acted on.  An investigation by the Health and Safety Executive (HSE) also revealed that chlorine dioxide units that were fitted at five sites to control legionella routinely failed to emit the required dosage to work effectively. Inspectors also found that water often failed to reach the 60°C temperature needed to kill the bacteria. In addition, the investigation established that staff at the hospital had not been provided with adequate training and instruction to be able to make informed decisions and take appropriate action.

In the second prosecution, on 4 September 2014, Basildon and Thurrock University Hospitals NHS Foundation Trust was fined £100,000 with costs of £162,000 after pleading guilty to Section 3(1) of the Health and Safety at Work Act 1974. In this case at least seven patients became infected with legionella from the hospital’s water system between 28 February 2004 and 31 December 2010. The HSE investigation identified a number of failures. In particular, it was found that the trust had failed to monitor the hot and cold water systems adequately or ensure that key parts of the system – such as the showerheads and hoses – were kept clean.

Raymond Cackett, 54, died in March 2010 as a direct result of developing Legionnaires’ disease. The trust’s failings also contributed to the death of 74-year-old patient James Compton in June 2007.

Take proper control

These two cases are a stark reminder of the importance of ensuring that organisations have proper control measures in place to monitor and control legionella risks. An employer (or someone in control of premises) has a legal duty to understand and manage legionella risks under the Health and Safety at Work Act 1974 (HSWA) and more specifically, the Control of Substances Hazardous to Health Regulations 2002 (COSHH). A breach of duty can result in a criminal prosecution and the penalty for an organisation convicted of an offence is an unlimited fine.

Risk assessments

Any water system, with the right environmental conditions, could be a source for legionella bacteria growth. There is a reasonably foreseeable legionella risk if your water system:

  • Has a water temperature between 20°C to 45°C;
  • Creates and/or spreads breathable droplets (e.g. cooling tower, or water outlets);
  • Stores and/or recirculates water (spa pools); and
  • Is likely to contain a source of nutrients for the organism to grow – such as rust, sludge, scale, organic matter and biofilms.
  • The most common sources of legionella are in man-made water systems including:
  • Cooling towers and evaporative condensers;
  • Hot and cold water systems; and
  • spa pools.

There are also a number of other systems that may pose a risk of exposure to legionella, such as humidifiers, air washers, emergency and showers. So it is important to undertake a risk assessment of your water system and any appropriate control measures put in place. You must first consider whether you can prevent the risk of legionella by looking at the type of water system you need. For example, identify whether it is possible to replace a wet cooling tower with a dry air-cooled system. The key point is to design, maintain and operate your water services under conditions that stop or adequately control the growth and multiplication of legionella. If you identify a risk that you are unable to prevent, you must introduce a course of action (such as a written control scheme to help you to manage the risk from legionella by implementing effective control measures and keep accurate and up-to-date records of those control measures.

The introduction of the new sentencing guidelines towards the end of 2015, applicable to all health and safety offences, will mean that organisations convicted of failing to control legionella risks substantial fines. For large and very large organisations those fines could be in the millions of pounds. It has never been more important to ensure that a legionella risk assessment is undertaken, appropriate control measures are put in place, and employees receive adequate instruction and training so that those measures can be correctly implemented.