Swimmers exposed to deadly gas at leisure centre.

Two companies have been ordered to pay £120,000 in fines and costs between them after nine people were hospitalised when they were exposed to chlorine gas at a swimming pool in Staffordshire.

The incident took place at the Nuffield Health Fitness and Wellbeing Centre in Cannock on 7 March 2009. Honeywell Control Systems Ltd was contracted to provide ongoing maintenance of the pool plant, and on the day of the incident one of its engineers was attempting to top up the day tank, which releases a disinfectant into the pool.

The engineer was meant to add a mixture of sodium bisulphate and water to the tank, which contained a chlorine alkali. But he mistakenly poured in a container of sodium bisulphate acid, which caused a reaction and released chlorine gas into the pool’s plant room.

The gas leaked into the swimming pool where 20 members of the public were exposed to the fumes. Staff at the centre quickly evacuated the building and nine people, including four children, were taken to hospital for treatment. All of them made a full recovery.

The incident was investigated by Cannock Chase Council, which found the centre had failed to put adequate measures in place to separate containers of alkali and acid. Also the risk assessment in place was inadequate and out of date.

The council issued the centre two Improvement Notice, which required a fresh risk assessment to be conducted and ordered the creation of a safe system for storing and handling chemicals.

The investigation also identified that Honeywell Control Systems had failed to ensure the engineer was competent to do the work. He had been on a training course for handling chemicals, but he was six months overdue for attending a refresher course. It had also failed to ensure a suitable risk assessment was in place for the work.

Cannock Chase Council environmental health officer  said: “The risk assessments provided by both defendants were not suitable – they were insufficient and outdated. Nuffield’s fundamental error was not considering the enhanced harmful effects of incompatible chemicals combined.

“It was extremely disappointing to find that the health club not only had inadequate and out-of-date risk assessments at the time of the chemical-mix incident but also the same risk assessments had not been reviewed some 11 months after the chlorine-gas release.

Nuffield Health Wellbeing Ltd and Honeywell Control Systems appeared at Staffordshire Magistrates’ Court on 17 October. Both companies pleaded guilty to breaching s2(1) and s3(1) of the HSWA 1974 and reg.5(1) of the MHSWR 1999. They were both fined £45,000 and each was ordered to pay £14,755 in costs.

In mitigation, Honeywell said it cooperated with the investigation and has subsequently retrained its staff and carried out a new risk assessment at the site.
Nuffield Health Wellbeing said it has spent a large amount of money to refurbish the pool plant room and similar rooms at other centres it owns. It also confirmed that it complied with the enforcement notices.

After the hearing, EHO said: “In any client and contractor relationship both parties have duties and responsibilities under health and safety law to protect each other, their workforce and anyone else. As this case has highlighted, these responsibilities were not properly managed by either defendant, which led to an event that injured children.”