Dorchester Crown Court has fined a Dorset farmer and his two companies after exposure to toxic gases led to the death of a 29 year old employee in June 2009.
The farm owner was fined £15,000 after pleading guilty to two breaches of the Health and Safety at Work etc. Act 1974. He also pleaded guilty to two further breaches of the above act as director of one of his companies and was subsequently fined £45,000. A fine of £10,000 after pleading guilty to breaching section 42 of the Health and Safety at Work 1974 etc, was given to the farmer and his second company. The costs of £75,000 were ordered to be shared.
A Health and Safety Executive (HSE) investigation into the incident revealed that two farm workers were exposed to hydrogen sulphide gas while performing maintenance work to an anaerobic digestion (AD) plant at the farm.
The workers were exposed to the toxic gas when removing the top of a digester tank to check the stirring mechanism.
Both employees lost consciousness. When one regained consciousness he noticed that his colleague lay unresponsive. An ambulance was called but the farm worker was declared dead. The paramedic staff and two other farm workers were reported as being effected by the fumes.
The HSE investigation highlighted a number of unsafe practices. Firstly, no risk assessment had been performed to determine the risks of the operating plant or the opening of the tank. The tank was not designed to have the roof removed routinely and should not have been necessary had the plant been operating correctly.
The employees were not trained in the removal of the AD and the understanding of possible explosion and exposure was poor. Working at height was not performed with adequate knowledge or safety equipment,
Furthermore, the HSE told the court that a similar incident had occurred in 2008 which was not reported to the HSE. The masks that were provided were not well fitting and were removed shortly after the lid was removed. Lack of training led the staff to believe they were out of danger once the roof of the AD was lifted.
After the case was heard, HSE Inspector Annette Walker said:
“While farm energy generation from anaerobic digestion is an emerging application in the UK, anaerobic digestion has been used here for several decades for treatment of sludge by water companies.”
“The risks associated with access to confined spaces and the associated potential for exposure to hydrogen sulphide in anaerobic digestion facilities are well-known.”
“What has happened at that farm demonstrates the importance of having safe systems of work in place, particularly for maintenance and repair work where the risk of exposure is likely to be highest. The need for specialist skills and training also has to be recognised.”
Further information on the process of anaerobic digestion can be found on the HSE website at http://www.hse.gov.uk/waste/disposal.htm#anaerobic