Court case[1942] AC 509

The respondent Board employed a driver of a petrol tanker. He was sent to deliver petrol to a garage and, while the petrol was being transferred from the tanker into an underground storage tank at the garage, he lit a cigarette and threw away the lighted match, which fell on the floor and set fire to petrol vapour. A fire and explosion followed, damaging the tanker, the garage and neighbouring property. The Board's insurers, the appellants, had issued a policy that covered the Board's liability for its servants' acts; they contended that lighting a cigarette was an act done by the driver for his own comfort and outside the course of his employment, so that the Board was not liable and the policy did not respond.

The House of Lords (Viscount Simon LC delivering the leading speech) held the Board liable, and the insurers bound to indemnify it. The driver's act of lighting a cigarette and throwing away the match, though done for his own comfort, could not be separated from the work he was doing at that moment - superintending the transfer of petrol. It was a negligent way of discharging his duty of delivering petrol safely. An act which is negligent when done at the time and place of the employer's work, in the course of that work, is done in the course of employment, even though the act would have been harmless at another time and place.