Carbon Monoxide
CO · Measured in ppm
About CO
An odorless, colorless gas from incomplete combustion. At high levels it can be lethal indoors. Outdoor levels rarely reach dangerous concentrations but contribute to ground-level ozone formation.
Sources
Motor vehicle exhaust, industrial processes, residential wood burning, wildfires, gas stoves
Health Effects
Headache, dizziness, weakness, nausea, confusion, chest pain; lethal at high concentrations
EPA Standards
| Annual Standard | 9 ppm |
| 24-Hour (Daily) Standard | 35 ppm |
Frequently Asked Questions
What is Carbon Monoxide?
An odorless, colorless gas from incomplete combustion. At high levels it can be lethal indoors. Outdoor levels rarely reach dangerous concentrations but contribute to ground-level ozone formation.
Where does CO come from?
The main sources of Carbon Monoxide include: Motor vehicle exhaust, industrial processes, residential wood burning, wildfires, gas stoves.
What are the health effects of CO?
Exposure to Carbon Monoxide can cause: Headache, dizziness, weakness, nausea, confusion, chest pain; lethal at high concentrations.
What is the EPA standard for CO?
The EPA has set an annual standard of 9 ppm and a 24-hour (daily) standard of 35 ppm for Carbon Monoxide.