Legionnaires Disease: Controlling Risks Associated with Spa's, Baths & Hot Tubs

Introduction

You are probably already aware that people can catch Legionnaires' disease from exposure to contaminated water droplets. Air conditioning systems (including cooling towers), and hot and cold water systems in buildings are common sources. But did you know that people using your spa bath(s) could also be at risk from catching Legionnaires' disease, as well as other infections (eg folliculitis - a skin infection caused by the bacterium Pseudomonas aeruginosa)?

This Information Sheet only covers legionella; giving you some guidance on how to meet your responsibilities under health and safety law, and in turn prevent people from being exposed to legionella. For more details on your responsibilities, and how you can meet them, you will need to consult the HSE's Approved Code of Practice (ACoP) and guidance Legionnaires' Disease: The control of legionella bacteria in water systems. HSE hopes a more detailed guidance, covering all issues of safely using spa baths, will be published in the near future.

Who is this Information Sheet aimed at?

If you supply spa baths or manage premises where one or more are used, eg:

• health clubs and leisure centres,
  


• hotels,
  


• swimming pools,
  


• a communal spa bath for residents in a block of flats etc,

you have responsibilities under several pieces of health and safety law

• the Health and Safety at Work etc Act (HSWA) 1974,
  


• the Control of Substances Hazardous to Health (COSHH) Regulations 2002, and
  


• the Management of Health and Safety at Work Regulations (MHSWR) 1999,

to manage any risks associated with using the equipment.

What is a spa bath?

A spa bath is a 'self-contained body of warm water designed for sitting rather than swimming in, which has a mechanism to ensure the water flows around the user'. It is designed for a small number of people to use at one time. The water temperature is kept between 30 to 40oC, and is not usually drained between users, so has to be continually filtered and cleaned. A hydrojet circulation or air induction bubble system is used to stir up the water.

You may also call your spa bath a spa pool, hot spa, hot tub, portable spa, or whirlpool spa (a term commonly used in American publications). 'Jacuzzi' is the trade name for one type of spa bath.

This guidance covers the following spa baths or related products:

• a domestic spa - a spa bath supplied to a private residence for private use;
  


• a public spa - a spa in a commercial, public or private building to be used by people visiting the building (whether they pay to use it or not), including a spa bath for joint use by residents of dwellings such as flats;
  


• a swim spa - a combined spa bath and swimming pool (this could be one pool or a spa bath attached to a larger swimming pool); and
  


• a whirlpool bath - similar to a spa bath, however, draining between each use will reduce the level of risk associated with it.

What is Legionnaires' disease?

This is a potentially fatal form of pneumonia caused by the legionella bacteria. There are actually several pneumonia-like diseases caused by different types of legionella bacteria, known as legionellosis. Some of these are less serious than Legionnaires' disease, eg Pontiac fever, with flulike symptoms.

Anyone can be infected by legionella bacteria but older people (over 45), smokers, heavy drinkers, those suffering from chronic breathing problems or kidney disease, and those with impaired immune systems (eg HIV positive) are more likely to develop life - threatening symptoms.

Legionella bacteria occur naturally in our environment (rivers, lakes etc) where they are not a problem for people. However, they also live in water systems associated with buildings and the workplace, eg hot or cold storage tanks, cooling towers, fire-fighting equipment, spa baths. In these situations if the bacteria get into water sprays or mists people can breathe them in. Exposing the lungs to the bacteria could then lead to Legionnaires' disease.

The bacteria can survive at low temperatures, although will not multiply. However, at 20 to 45oC they thrive and readily multiply. Above 60oC they are killed off.

Why do you need to consider the hazard of Legionnaires' disease?

There have been several outbreaks of Legionnaires' disease where the cause was traced back to a spa bath. Large numbers of people were infected and quite a number died. You may not have heard of these only because the worst cases occurred in Belgium and the Netherlands. People can be exposed while using a spa bath, but also by just being close enough to it to breath in the fine spray created.

Legionella are a particular problem in spa baths because:

• the water is at an optimum temperature for them to grow;
  


• dirt, dead skin cells etc from the people using them accumulate providing food;
  


• the piping for the air and water circulation provide a large surface area for the bacteria to grow on; and
  


• the agitated water forms aerosols and spray via which the bacteria can be breathed in.

What else needs to be considered?

Do not forget that the chemicals used to clean the water in spa baths can be hazardous.

Spray cleaning the spa bath could also expose your staff to the legionella bacteria.

You should not automatically put chemicals used to treat the water (called biocides) into the sewers; you will need consent from the Environment Agency.