Valero Energy had to pay out £5 million after an oil explosion killed four workers and seriously injured another at an oil refinery in Pembrokeshire, Wales.
In 2011 five workers were emptying a tank using a vacuum tanker when the explosion and subsequent fire occurred. The blast resulted in a fire ball, which severed the tank roof and projected it 55 metres where it hit a Butane storage sphere. The roof narrowly missed a pipe track where a range of flammable materials were transported.
A HSE investigation identified the explosion was most likely caused by an ignition of the highly flammable atmosphere in the tank. The incident occurred during what should have been a routine emptying of the tank in readiness for further cleaning and maintenance. The HSE also found there had been long standing failures in the refinery safety management systems. As a result risk in the flammable tanks were not understood and therefore not controlled.
Valero Energy pleaded guilty at trail and was fined £5 million and ordered to pay £1 million in costs.
