WAC 296-307-42523. Portable engines used indoors

(1) Portable engines may be used in buildings only for emergency use, and according to WAC 296-307-42521 . (2) Exhaust gases must be discharged outside the building or to an area where they will not constitute a hazard. (3) Provision must be made to supply sufficient air for combustion and cooling. (4) An approved automatic shut-off valve must be provided in the fuel system ahead of the engine, designed to prevent flow of fuel to the engine when the ignition is off or if the engine should stop.