AN investigation is under way after a chemical leak at a paint factory early yesterday.

Hundreds of people were affected by the incident at the 3M factory, on Standard Way Industrial Estate, in Northallerton, North Yorkshire.

It is understood the leak involved 600 litres of waterbased resin, which triggered an automatic fire alarm, resulting in a 400m exclusion zone being put in place.

A security guard was the only person inside the factory at the time. No one was injured.

Emergency services were called to the factory, which employs 120 people, at about 6am.

The exclusion zone included the closure of the A167, a main route into and out of town, causing lengthy delays.

Although the road was reopened by 10.30am, the factory was not declared safe until mid-afternoon.

Emergency services said there was no danger to the public, although nearby residents were advised to stay indoors and keep windows closed.

Neighbouring businesses were also affected, with staff unable to get into their premises.

Inspector John Wilkinson, of North Yorkshire Police, said: “The chemical released was a mild irritant and there was no risk of harm.

“Thanks to the co-operation, understanding and patience of local people and businesses, we were able to bring the incident to a safe and swift conclusion.”

The Health and Safety Executive has been informed and is expected to investigate, while 3M will carry out its own investigation.

A spokesman for the company, which last month announced proposals to cut 15 jobs at its Northallerton site, said: “The reaction was contained within the plant. There have been no injuries and we hope to reopen soon.

“A full internal investigation will be taking place to ensure such an incident does not happen again. 3M would like to apologise for the inconvenience this has caused to our neighbours and motorists in the area.”

Car dealership Sherwoods was one of the businesses affected.

Managing director Alasdair MacConachie said: “It could have been an awful lot worse. I was originally led to believe there was a fire, which could have been catastrophic.”

Vic Ison, manager of CB Furnishings, another affected business, said the incident was the first of its kind in his 25 years on the industrial estate.