Utility machine with a gas driven combustion engine

The machine has an electrical system and an internal combustion engine (1) supplied by a gas system (2). A manually and/or automatically operated emergency on-off switch (6) interacts with the electrical system and/or a fire-inhibiting medium reservoir. The electrical system can be switched to a no-current state by the on-off switch and the reservoir can be switched to open by the on-off switch to deliver fire-inhibiting medium to near the gas system.