DORSET Fire and Rescue Service has issued a countywide warning after a microwaveable wheat bag exploded, causing a fire.

Microwaving wheat bags and then placing them on muscular injuries is becoming increasingly popular, but many people are putting in bags that are too big for the microwave, which results in the turntable not working properly and sparking a fire, officials have said.

Investigation of fires started by microwaveable wheat bags has shown the wheat produces an exothermic reaction and thermal temperatures above 225c.

These temperatures can be reached quickly in a microwave oven working normally, but the time is significantly reduced if the turntable is not working properly or is obstructed as this may create ‘hot spots’ within the bag.

Firefighters were called to a house in Bournemouth yesterday afternoon after a wheat bag exploded in a microwave.

Fire investigation officer Stuart Jeneson said: “Always follow the manufacturer’s instructions carefully and to ensure a wheat bag is not heated in a microwave for too long, or at too high a temperature.”