Update, 3pm: Police have confirmed that Pennygillam Industrial Estate has fully reopened following a full clean-up of the Kensey Foods site.

Insp Taylor said: "There was no escalation of incident and it became clear that we could clean-up fairly quickly.

"On behalf of the emergency services I would like to thank everyone for co-operating and everything is now open as usual."

A spokesperson for Kensey Foods confirmed the spillage was in the waste processing area of the factory and not the bakery production site.

Four casualties have been decontaminated after a 500-litre chemical spillage at Pennygillam Industrial Estate, this morning.

Emergency services have been working on site at Kensey Foods factory, since the initial call at 6am. Fire crews, with 41 members, from Launceston, Callington, St Austell and Liskeard are on the scene, along with a decontamination unit from Saltash and the Environment Agency for precaution.

Speaking on site, Inspector Martin Taylor from Bodmin police station, told the 'Post' the chemicals had now been contained and there was no danger or direct risk to the public.

He said: "As far as I am aware, there is no threat to the environment at this time. Four members of staff have all been decontaminated. One self discharged themselves and the other three have been admitted to hospital with minor injuries."

Cordons for half of the industrial still remain in place, but Quarry Crescent and some surrounding businesses have been able to reopen.

Insp Taylor advised anyone working on the industrial estate to contact their employers or managers to seek advice from them.

Station Commander for Launceston fire station, Gary Chapman, said the chemical had been identified and teams were working to decontaminate the affected area.

"It is a slow process, because we don't want to make it worse," he said. "The factory isn't being evacuated, some are still in the production area, but we are happy that it is safe."

Residents in the area are being asked by Cornwall Council to put their waste and recycling out for collection as normal.

A council spokesperson said: "The current closure of parts of the industrial estate following the chemical spill may mean that the items are collected later than usual but they will be collected during the day."

The time of full reopening of the industrial estate remains uncertain, however emergency services say it could be around 3pm.