The British and Irish Spa and Hot Tub Association (BISHTA) is alerting consumers of the risks presented by a few hot tub brands who seem to be encouraging consumers to exceed the recommended maximum safe water temperature of 40°C, as stated in the European Standard for domestic spas and hot tubs (BS EN 17125).
A practice with serious risks
Bathing in water exceeding 40°C is potentially harmful
BISHTA advises consumers that bathing in water exceeding 40°C is potentially harmful and should be avoided.
While there are many benefits from warm water immersion (typically between 36°C to 38°C, but not more than 40°C), there is growing concern from BISHTA that soaking in water over 40°C during hot tub use can increase the risk of heat stroke, or impairment of the body's ability to regulate its internal temperature and even cause fatalities.
In the USA, the Consumer Product Safety Commission issued guidance as far back as the late 1970's warning of 10 recorded deaths in hot tubs which were heated more than the safe maximum temperature of 40°C (please note that three of these ten deaths were alcohol as well as temperature-related). These conditions can be fatal even to fully healthy adults.
BISHTA recommendations for health on spas
Here in the UK, public health authorities have produced guidance for hot tubs used in holiday parks (HSG 282 - the control of Legionella and other infectious agents in spa pool systems) recommend an upper temperature of 40°C.
And now an investigation by BISHTA into the UK market has revealed a small number of hot tub brands and models that are advertised to exceed the maximum recommended safe temperature of 40°C, putting consumers' health at risk.
Reputable brands will be factory configured in such a way as to make this increased temperature impossible, but BISHTA recommends that you keep on hand a good quality thermometer to double check the water temperature against that showing on the hot tub's display.
Please let us know of any manufacturers/retailers who are advertising that their hot tubs are exceeding 40°C so that we can inform the relevant agencies and also other consumers.
Reducing the risk of hazards
BISHTA promotes safe hot tub standards, and the trade association is not aware of any recorded incidents of hot tubs or exercise spas, which have been built to industry standards, and are correctly installed, serviced and maintained, being the cause of fire, electrical problems or causing other harm to users.
If a product's quality is inferior, this has the potential to create a hazard, and so BISHTA recommends that consumers buy from a reputable source. Peace of mind can come from purchasing a hot tub from a BISHTA member, who will be able to offer the reassurance of other aspects of the product safety standards.