Carbon monoxide from gas engines

Carbon monoxide, or CO, is a gas with no color and no smell. Every gas or propane engine makes it. Outside in open air, it blows away. In a closed or partly closed space, it builds up. On landscape and hardscape jobs, that means running a plate compactor in a garage, a cut-off saw in a basement window well, a pressure washer under a covered patio, or a generator next to an open door. The rule sets limits on how much of gases like CO a worker can breathe and says the company must use controls first, like better air flow or a different tool, before relying on anything else.

The best fix is to keep gas engines out of enclosed spaces. Use an electric or battery tool indoors when there is one. Put generators, pumps, and pressure washer engines outside, far from doors, windows, and air intakes, with the exhaust pointed away. Opening a door or running a fan does not make it safe to run a gas engine inside. CO can still build up. If the job truly needs a gas engine in a tight space, the company has to plan it: test the air with a CO meter, set up ventilation that moves real air through the space, and decide who watches the meter. A CO meter that beeps means get out now, not finish the cut.

Know the signs. Headache, dizziness, feeling sick to your stomach, feeling weak, and being confused are early signs of CO. They feel like the flu or the heat, so people ignore them. If you or a coworker feel this way while an engine is running nearby, shut the engine off if you can do it quickly, and get everyone into fresh air. Do not go back in to get tools. If someone is confused, passes out, or does not get better fast in fresh air, call 911. Do not run engines inside a box truck or trailer to warm up or charge things. Do not sit in a running truck with the windows up next to a running generator.