FIRE crews faced a race against time to save £10m of frozen food during a lethal chemical leak yesterday.

Around 200 people were evacuated and roads closed off as harmful anhydrous ammonia was spewing from a coolant tank at a Merseyside Iceland distribution centre.

Cheshire fire fighters at the scene were told they had just hours to isolate the leak and get the cooling system back to full strength before food started to perish.

Crews were called to Hardwick Grange in Woolston, near Warrington, at around 1.40pm.

An engineer was working on a two-tonne tank filled with pressurised ammonia when he noticed a valve had come loose.

He fled from the building and raised the alarm.

Fire fighters wearing air-tight body suits and breathing gear went into the building to isolate the leak and test how much of the corrosive chemical had escaped.

Ammonia absorbs water and causes painful burns on the skin. Station Manager Barry Rose, who was the commander at the scene, said a safe level for ammonia in the air is 35 parts per million (PPM). When crews first sampled the air around the tank it was found to contain 6,000 PPM.

Mr Rose said: “It would have been fatal to be inside at the levels it was at.

“We were on a pretty tight timescale to isolate the leak and remove any excess fumes from the building before we lost any of the food.”

He added that he was told there was around £10m of food stored in the building.

None of it was lost and there were no injuries from ammonia.

Fire fighters used positive pressure fans and a water curtain to fumigate the centre.

An 80m to 100m cordon was thrown up around the site and some local roads were closed off.

They included the B5120 Woolston Grange Avenue between its junctions with the A574 Birchwood Way, and the A57 Manchester Road.