Engineering firm Renishaw has been fined more than £13,000 after an explosion at is site which caused burns to an employee.
Aluminium powder reacted with water in an industrial vacuum cleaner to create hydrogen gas which exploded and burned a worker, a court has heard.
A 27 year-old employee suffered burns to the top of his body and was in hospital for two weeks. He was off work for three months before returning to work for the company.
Renishaw PLC, a research and development company, was today prosecuted by the Health and Safety Executive (HSE) following the incident at Whitebridge Way, Whitebridge Park, Stone, on 6 February 2012.
Stafford Magistrates' Court heard the specialist vac had been used to clean up aluminium powder before being left to stand over a weekend.
The powder reacted with water used in the machine to create hydrogen gas which exploded when the unassuming worker switched it on.
An HSE investigation found that had Renishaw undertaken a proper risk assessment it would have identified that a reaction could be caused by mixing metal powder with the water inside the cleaner.
Renishaw PLC, of New Mills, Wotton under Edge, Gloucestershire, was fined £7,000 and ordered to pay £6,397 in costs after pleading guilty to breaching Regulation 5 (1) of the Dangerous Substances and Explosive Atmospheres Regulations 2002.
Speaking after the hearing, HSE inspector Wayne Owen said: "This type of vacuum was not suitable for use with aluminium powder. Had the company paid attention to the instructions for working with this metal powder, or indeed the machine itself, then the incident could have been prevented.
"It must have been a very frightening experience for the worker, who suffered painful injuries.
"Aluminium powder mixed with water can create highly explosive gas and a suitable and sufficient risk assessment would have shown that they should not have been mixed."
