Shell has been served with two further notices by the UK's Health and Safety Executive (HSE) following a leak on its Charlie platform in the North Sea in May this year. 

Shell had initially been served with a Prohibition Notice, because the HSE said the potential for fire and explosion had been caused by the uncontrolled release of flammable or explosive hydrocarbons from safety critical pipework on one of the platform's legs, C4, on 19 May. 

The latest notices say the operator didn't take appropriate measures to prevent fire and explosion, because it "failed to detect pipework deterioration and implement remedial action to ensure the integrity of hydrocarbon containing pipework on the Brent Charlie offshore installation." 

The second notice says Shell "failed to ensure that safety critical extraction fan K-9635 was maintained in an efficient state, in efficient working order and in good repair," because "the fan failed to operate when required to extract hydrocarbon gas from C4 of the Brent Charlie installation, thereby exposing individuals to the risk of fire and or explosion."

The latest notices were issued late June. Shell was given until 30 September to comply. 

A further notice, an Immediate Prohibition Notice, was issued in June to Shell due to corrosion on part of the flare on the Armada facility, previously operated by BG Group. Pipework on part of the high-pressure flare system was found to be 1.6mm thick, when it should have been 7mm.