THE alarm was raised at Watford Museum on Tuesday morning after an old fire extinguisher was found to be leaking a strange substance.

Garston firefighters were called to the scene and examined the leak, which was coming from a box labelled as a fire grenade.

It turned out to be fire extinguisher not used since World War Two. The substance within a glass container used to be thrown onto a fire and the substance would be released and extinguish the flames when the glass smashed.

This type of fire extinguisher has been withdrawn from public use because the carbon-based substance involved gives off fumes which are carcegenic.

Firefighters had to pack the extinguisher away in earth and pass it onto the Environmental Agency to be disposed of.