BP site fined £30,000 over toxic gases leak

The release of synthesis gas or “syngas” at the BP Chemicals site in Saltend was caused by a faulty valve and led to the release of 572 tonnes of the gas between November 10 and December 11, 2009.

The released gas consisted of 324 tonnes of carbon monoxide, 175 tonnes of carbon dioxide, eight tonnes of methane and 65 tonnes of hydrogen. Carbon monoxide is toxic and together with methane and hydrogen has the potential to be highly flammable.

Hull Magistrates’ Court heard there were no alarms to detect the release, which happened when the valve failed, causing vibration leading to the fracture of a metal tube in one of the site’s heat exchangers.

This caused syngas to enter a cooling water line and be released into the atmosphere from a cooling tower.

The leak was only detected when a technician’s personal carbon monoxide alarm went off while he was carrying out tests.

The court heard there had been two previous unauthorised releases of the gas in 2004 and 2005.

The company pleaded guilty to breaches of its environmental permit and in mitigation said it was a single incident with no breach of air quality standard for carbon monoxide.

The firm said no harm was caused to employees or the public, and that the environmental impact was minimal.

Speaking after the case, Darren Leng, regulatory officer at the Environment Agency said: “Whilst on this occasion there was no impact on the environment or human health, we take breaches of environmental permits very seriously.”