Hot tubs are very popular with the public, but it is easy to cause some very serious, even fatal, illness and infections if the pool and the water are not managed properly. If this happens the pool operator is liable and could be sued by the client, or even prosecuted by the Council or the Health and Safety Executive if the standards fall considerably below the guidance available to pool operators.
Hot tubs and spa pools usually have heated water between 30 and 40C which is filtered, chemically disinfected, circulated, agitated and not changed after every use.
Bathing loads may be high in spa pools and combined with high temperatures this can make it difficult to maintain a satisfactory level of disinfectant, a suitable PH value and reasonable microbiological quality. If not carefully managed the water can build up high levels of bacteria such as Psuedomonas aeruginosa which can cause boils, skin and ear infections, or Legionella which can cause a serious pneumonia.
If you choose to provide a spa pool, make sure you purchase from a reputable supplier and have it installed by suitable contractor. They should be able to give further technical advice on the cleaning and maintenance of the hot tub, and may be able to give you written procedures and assessments.
Before installing and using spa pools/ hot tub you must consider the risk of Legionella. The Health and Safety Executive have written a guide for duty holders, The Control of Legionella Bacteria in Water Systems. This tells you what you must do to reduce the risk of Legionella growing in your pool; starting with choosing the right system, what training on risks and procedures you must give to staff, chemicals to use, daily tests and other checks that are needed, and the cleaning routine needed each time the pool is emptied between clients.
You will have to complete a risk assessment for Legionella and other infections in spa pools and hot tubs. Although you do not have to write this down unless you employ 5 or more staff, we strongly recommend that you do. You will not be able to show your insurance company, or any enforcement agency, what you do to ensure you manage the pool unless you have appropriate records. So for your own due diligence defence in the event of legal action, you need to write down your risk assessments and procedures and maintain your training records and records of testing done on the pool water.
You also need to complete a risk assessment for the pool chemicals under the Control of Substances Hazardous to Health Regulations 2002 (COSHH). There is a legal requirement under COSHH, reiterated in the Health and Safety Executive guidance, to keep operational records for 5 years These must include water test results which should be carried out at least twice a day to show the disinfectant level and the pH value.
You should also be testing for alkalinity, total dissolved solids and calcium hardness once a month.
Microbiological testing should be done at least every month and Legionella testing every three months. You will need to contact a company or laboratory to assist you with this.
The definitive guidance on pool water quality has been produced by the Pool Water Treatment Advisory Group and is available from their website for £70.
Hot tubs should be used by a small specified number of people at any one time. The water should be changed after each rental, or weekly whichever is shorter. Hot tubs are not suitable for continuous shared communal use such as tenants of several chalets or flats.
You should implement hot tub rules for your customers including:
- No user should put their head under water
- Children and other users who cannot keep their faces out of the water should not use the hot tub.
- Under 4 year old children should not use the hot tub.
- Under 8 year old children should not use a hot tub over body temperature (37C).
- Children must be supervised
- Babies nappies should not be changed beside the hot tub.
- Users should not be immersed for more that 15 minutes
- The maximum number of bathers specified for the hot tub should not be exceeded
- Hot tub should not be used after a heavy meal or while under the influence of alcohol or sedatives
- Pregnant women, and those suffering from heart or circulation problems; fits; or who are immunocompromised must seek medical advice before use.
Documenting how you let your customers know and how you enforce these rules would form part of your risk assessment and due diligence defence.