At CO levels above 35 ppm, which action is required?

At CO levels above 35 ppm, which action is required?

• A. Increase ventilation and continue operation
• B. Notify local authorities
• C. Evacuate the space oneself
• D. Operators are required to evacuate space

Answer: (D)

Carbon monoxide is a toxic, colorless, odorless gas, so any elevated level is a serious safety concern. When exposure reaches 35 ppm, the immediate priority is to leave the area. Evacuating minimizes your risk because CO can cause headaches, dizziness, confusion, or loss of consciousness, and symptoms can develop or worsen quickly with continued exposure. Ventilation or continuing operation does not reliably remove CO and can even spread it to other spaces, so they are not adequate stand-ins for evacuation. After evacuating, alert building management or call emergency responders so the source can be identified and the space tested before anyone re-enters. If you’re trained and it’s safe, you may shut off the CO source, but do not stay in the area to attempt this—your safety comes first.

Carbon monoxide is a toxic, colorless, odorless gas, so any elevated level is a serious safety concern. When exposure reaches 35 ppm, the immediate priority is to leave the area. Evacuating minimizes your risk because CO can cause headaches, dizziness, confusion, or loss of consciousness, and symptoms can develop or worsen quickly with continued exposure. Ventilation or continuing operation does not reliably remove CO and can even spread it to other spaces, so they are not adequate stand-ins for evacuation. After evacuating, alert building management or call emergency responders so the source can be identified and the space tested before anyone re-enters. If you’re trained and it’s safe, you may shut off the CO source, but do not stay in the area to attempt this—your safety comes first.