ELEVEN people were treated after a leak of carbon monoxide at a Thurrock industrial site.

Firefighters were called to the industrial unit on Motherwell Way, Grays, late on Monday (6 September) afternoon after a number of people there began to feel unwell.

After evacuating the building, crews used gas monitoring equipment to measure carbon monoxide levels and found there were severe levels in the air.

Firefighters immediately started to search the building for the cause while requesting support from other emergency services.

Incident Commander Russ Freeman said: "In total, eleven people have been treated after being overcome by carbon monoxide. Their condition is not being treated as life-changing or life-threatening.

"We've been searching the building to find out where the carbon monoxide is coming from, and so far have been unable to identify the cause.

"We'll continue to search while we monitor the gas levels in the air, and thankfully we can already see levels are reducing.

"I'd like to reassure local residents that the carbon monoxide levels are contained to the building, and even when we ventilate the unit, there is no risk or safety concern to the wider area or public."

The cause of the carbon monoxide leak was found to be in a wire inside pipe insulation that had burned due to an electrical fault. The temperature in the pipe insulation was low so the wire did not cause a fire but was slowly decomposing creating carbon monoxide.

Firefighters remained at the scene until 8:45pm and left the scene in the care of the building occupier.