A BUILDER working at the site for the new Blackburn hospital was injured after a canister exploded and hit him in the chest.

And today firefighters warned of the dangers of leaving aerosols too close to heaters, which can make them burst.

The 38-year-old, based at the site for the new Queens Park Hospital, was hit by a can of expanding foam, which had been left in front of a portable radiator.

The Balfour Beatty employee was taken to the accident and emergency department, further along Haslingden Road, to be treated for bruising.

Watch manager Keith Cunliffe, of Blackburn fire service, said the incident should be highlighted as a lesson to others. He said: "Aerosols should never be left close to heaters. It was probably an accident. Maybe the heater had been moved. But it is very dangerous.

"Luckily in this case the canister did not set alight. Therefore, there were no burns. But people should be very aware of the risks of leaving these items close to heaters even for a few minutes."

The engineering and construction company has launched an investigation into the incident. But the firm confirmed that the employee was back at work.