An oil storage company in Ellesmere Port has been fined after contractors cut into a sealed pipe causing an explosion inside a tank.

Liverpool Crown Court heard that on January 19, 2015, contractors of ESL Fuels Ltd cut into a sealed pipe using a grinder.

The pipe, which was attached to a tank, was being used as part of a waste oil recovery process at the firm’s North Blend Tank Farm.

Flammable gases within the pipe ignited resulting in an explosion within the tank and the tank lid and vent pipe being partially detached and projected over a raised walkway.

An investigation by the Health and Safety Executive (HSE) found that the company was having difficulty with the waste oil recovery process which was foaming out of the vessel and filling its bund.

Ellesmere Port firm ESL Fuels was fined £100,000 with £17,000 costs following an HSE investigation into an explosion

The company’s tests were inadequate and failed to identify the cause of the problem which was generating flammable carbon monoxide gas.

A decision was taken to connect the vessel by pipework to an emergency relief dump tank to prevent a potential catastrophic overpressure in the tank but the safety implications of this modification and its design were not risk assessed.

HSE also found systemic failings with the company’s management of contractors and an inadequate permit to work system with the contractors being unaware that the tank and pipework were in use and may contain flammable gas when carrying out hot work that was a source of ignition.

ESL Fuels Ltd, based at the Stanlow Oil Terminal, pleaded guilty to breaching two sections of the Health and Safety at Work Act 1974 and were fined £100,000 and ordered to pay costs of £17,000.

Speaking after the hearing HSE inspector Matthew Lea said: “Even though nobody was injured this incident could have been prevented if the problems with the process and the subsequent design modification had been properly investigated, risk assessed and dealt with and if the work of the contractors had been adequately controlled.

“The contractors were unaware that they were working on a live process in the north blend tank farm nor how it could impact on their safety.

“HSE has brought this prosecution because failures took place that could have resulted in death or serious injury and we believe every person should be healthy and safe at work.”

Richard Donovan, general manager at ESL, commented: “We take health and safety very seriously.

“We conducted a thorough investigation following the incident in 2015 and additional measures were swiftly put in place to ensure it could not happen again.

“No one was hurt on site and there were no effects on the general public. We accept the court’s ruling and take full responsibility for such matters.”

The HSE is Britain’s national regulator for workplace health and safety.