Carbon Monoxide

in Enclosed Parking Facilities, Service Stations, and Vehicle-Repair Facilities

Why am I being warned about potential exposure to carbon monoxide in enclosed parking facilities, service stations, and vehicle-repair facilities?
  • Carbon monoxide (CO) is on the Proposition 65 list for reproductive toxicity.
  • Exposure to high levels of carbon monoxide during pregnancy can affect the baby’s brain development and cause loss of pregnancy.
  • California’s Proposition 65 requires businesses to warn people before exposing them to a significant amount of a chemical listed under Proposition 65 for cancer or reproductive toxicity.  
What is carbon monoxide?
  • Carbon monoxide is a colorless, odorless, and poisonous gas.
  • It is formed during the combustion of various fuels, including gasoline, diesel fuel, natural gas, wood, coal, kerosene, and propane, as well as plant-derived substances such as tobacco smoke and cannabis (marijuana) smoke.
  • Carbon monoxide can replace oxygen in the bloodstream. During pregnancy, reduced levels of oxygen in the bloodstream can affect the development of the baby’s brain.  

How does exposure to carbon monoxide occur in enclosed parking facilities, service stations, and vehicle-repair facilities?
Carbon monoxide is produced during combustion
People breathe air that contains carbon monoxide

During pregnancy, carbon monoxide can pass from mother to baby.

How can I reduce my exposure to carbon monoxide in enclosed parking facilities, service stations, and vehicle-repair facilities?
  • Do not idle your vehicle in enclosed parking facilities, service stations, and vehicle-repair facilities. Carbon monoxide in motor-vehicle exhaust can build up very quickly.
  • Limit the time you spend in these facilities.
For more information:

General Fact Sheets and Resources

Scientific Information on Carbon Monoxide

Proposition 65

Updated February 2025

Related Chemical(s)

References
Chemical
Product/Place