People living in the Dutch town of Moerdijk near Rotterdam have reacted with astonishment to news that some 25 tonnes of a ‘dangerous’ gas have leaked into the atmosphere from a Shell refinery over the past 2.5 months.

Shell said on Wednesday evening that a leak had been fixed. One tap had been left open following repair work carried out in November and had only just been discovered, the oil giant is quoted as saying by broadcaster Nos.

‘How can this have happened for so long without Shell noticing it?’ local councillor Raymond Cools told the broadcaster.

Ethylene oxide is carcinogenic and is a component in many consumer products including detergents.

No danger

However, Shell said it had not recorded any dangerous concentrations of the chemical. The tap was 25 metres from the ground and the gas disappeared quickly into the atmosphere, Shell said.

Moerdijk mayor Jac Klijs told Nos he wants an inquiry into how this could happen. ‘It is extremely annoying that we have yet another incident at Shell,’ he told Nos. ‘It is more annoying that it took two months to find this out.

‘I do want to have it confirmed that the health of our residents has not been at risk. The first findings of the local health board would appear, happily, to indicate that is the case.’