Corus has been issued with an improvement notice

The Environment Agency carried out an investigation after dust was found in parts of Dormanstown and Redcar.

Officers concluded that it was highly likely the non-harmful substance was linked to iron ore from the site.

An improvement notice was issued which gives Corus a list of 11 actions and 6 months to carry them out.

The powder, which resembles brick dust, was reported to the Environment Agency during the week of 8 November by several residents.

'Non-hazardous'

Officers took samples and sent them away for physical and chemical analysis.

Les Thomas, an officer with the agency said: "The dust itself is a non-hazardous inert powder mainly consisting of iron oxide which forms on the surface of the lump ore.

"It has been linked by colour and chemical composition with the dust arising from a particular iron ore used as a raw material in the blast furnace.

"We have served an improvement notice on the company designed to make Corus reassess how it handles its iron ore operation in the future to prevent it happening again.

"This covers looking into whether the dust can be removed before coming into the county, handling and storage operations, and moving the iron ore on the site itself."

In a statement, Corus said: "The company has co-operated fully with the Environment Agency in their enquiry.

"We already take measures to reduce the lift off of dust but will be progressing with the Agency's recommendations."