Not sure about OSHA. But the mill's rules were, warning at 75. Allowed to work the entire shift, but investigate and be aware.OSHA doesn't care as much. They have a limit of 5,000 ppm for a 10 hour day.
At 200, secure equipment to a safe condition, and evacuate to primary evac point. Look at monitor. Evac to secondary point if necessary.
Crap.
Just realized.
I'm talking CO,
They're talking CO2