A COMPANY with a previously unblemished safety record could face a fine of millions of pounds following an industrial accident which led to a man losing his leg.

Dennis Chadwick was an inspecting engineer as a pressure check was carried out on the Wilton 10 boiler in Teesside, in December 2013, when a "catastrophic" fault led to a metal connector being blasted out of the test rig and into his leg.

He has endured over three years of painful treatment, and more than a dozen operations as surgeons tried to elongate his bones and save his leg.

However, last month they took the decision that Mr Chadwick's leg would have to be amputated below the knee.

Sembcorp Utilities UK, which operates Wilton 10 power plant, near Redcar, and its subcontractors CIS, have admitted charges of failing to ensure Mr Chadwick's health and safety, and that of other employees, during the test on December 3, 2013.

Mr Chadwick's employers R&A Kay Inspection Services admitted a charge of failing to ensure his health and safety, in charges brought by the Health and Safety Executive.

As a large company, Sembcorp – which has never before faced a health and safety prosecution – could be fined up to £6m, while CIS and R&A Kay, as smaller companies, face five and six-figure fines.

Austin Stoton, prosecuting, outlined the ways safety guidelines had been breached and said: "There were seven people there exposed to a risk of either death or serious injury. Any one of them could have been killed."

While the risk around the boiler was adhered to, the potential risk from the test rig set up to check the boiler pressure had not been considered in enough detail.

Mr Stoton added: "That is really the most glaring elephant in the room, when it comes to risk associated with this case, that the test rig danger wasn't taken into account."

The court heard Sembcorp hired contractor CIS to carry out the pressure testing, under the instruction of engineers from Sembcorp itself, despite the fact CIS is an industrial cleaning company, and its employees admitted they had not been properly trained in pressure testing.

They were also not adequately briefed by employers, and were allowed to stand too close to the equipment, which did not have barriers around it to protect them.

Pressure built up to high levels within the test rig pump, and a disc which should have released some of that pressure was set at the wrong level, causing the blast which led to the metal connector hitting Mr Chadwick, who was standing only one to two metres away.

The disc settings were overlooked by a CIS employee, but also should have been checked by Sembcorp, Judge Hickey heard.

Mr Stoton said there were "serious systemic failures" which led to a "high likelihood of harm".

In mitigation, Mark Harris, on behalf of Sembcorp, accepted the company had failed to comply with its own internal procedures, and made a public apology to Mr Chadwick, who attended the hearing in a wheelchair. Mr Harris said Sembcorp never been prosecuted or had any serious safety issues before this incident.

Johnnie Walker, acting for CIS, echoed the apology but said although it was a serious incident, it was isolated and should be measured against the company's previously unblemished safety record, exceeding 23 years in an inherently dangerous industry.

Jonathan Mitchell, for R&A Kay Inspection added that Mr Chadwick, who works for the company, was a highly skilled and experienced operative, and that in retrospect the company's risk-assessment had not been adequate on this occasion, although he had said there was a "real dispute" over how much it was to blame.

Sentencing was adjourned until a later date, but it is understood to be some time next month.