Abstract: A safety shut-off device is disclosed. The device is adapted for use with a gas welding apparatus, the apparatus having a torch handle and a supply of a pressurized combustion reagent. The safety shut-off device has a valving assembly that is adapted to be positioned between the torch handle and the supply of pressurized combustion reagent. The valving assembly is actuatable between a first state and a second state. In the first state, the torch handle is operatively connected to the supply of pressurized combustion reagent. In the second state, the handle is operatively disconnected from the supply of pressurized combustion reagent. The valving assembly is biased towards the second state and actuatable from the first state to the second state substantially instantaneously. The safety shut-off device also has an actuating mechanism. At least a portion of the actuating mechanism is adapted to be positioned on the handle for being grasped by the user of the gas welding apparatus when the user grasps the handle.