Carbon Monoxide Frequently Asked Questions

1. What is carbon monoxide?

Carbon monoxide (CO) is a colorless, odorless, tasteless gas that is poisonous in relatively low concentrations.  It consists of one atom of carbon and one atom of oxygen.

2. Where does carbon monoxide come from?

CO is generated to some degree whenever anything burns.
This includes:

Liquid Fuels - gasoline, diesel fuel, kerosene, lamp oil
Gasses - natural gas, LP gas, methane, any gas that burns
Solids - wood, paper

3. What levels of carbon monoxide are safe?

Any level of carbon monoxide in the air you are breathing is cause for concern. The long-term effects of continuous low-level exposure has not been sufficiently investigated. There are no long term studies that have monitored the overall impact of living in a constant CO-laden environment.

Even safety organizations (government and private) have different conclusions concerning safe levels of exposure.

The chart below shows the general effects of various levels of exposure. Note that OSHA limits safe exposure at 70ppm for no more than four hours.

Toxic Gases are measured in parts per million (ppm).
1% volume = 10,000 ppm

OSHA Exposure Limits

What are the OSHA standards for CO exposure?

The OSHA PEL is 50 parts per million (ppm). OSHA standards prohibit worker exposure to more than 50 parts of the gas per million parts of air averaged during an 8-hour time period.
 
The 8-hour PEL for CO in maritime operations is also 50 ppm. Maritime workers, however, must be removed from exposure if the CO concentration in the atmosphere exceeds 100 ppm. 

The peak CO level for employees engaged in Ro-Ro operations (roll-on roll-off operations during cargo loading and unloading) is 200 ppm.

 4. Is it safe to use my oven to heat my house?

The short answer is - NO!! Don't use your oven for heat under any circumstances. (It is best to crack a window open when you use the oven for cooking for more than an hour.) You will eventually run out of oxygen in the area because the flames in the oven will consume it.

Since there is no exhaust, as the oven burners operate they will begin to burn oxygen-depleted air that has already been burned before. When that happens, the oven will quickly begin producing carbon monoxide.

 5. Why is carbon monoxide toxic?

Carbon monoxide is called "the silent killer" for good reason. You could be standing in a room full of it and not know it.

In high concentrations (around 2,000 ppm) you'll become unconcious in a few minutes. If you are not moved to fresh air or given oxygen, you'll be dead in a few hours.

CO interferes with the blood's ability to carry oxygen throughout the body. Carbon monoxide attaches to the iron molecules in the blood and prevents oxygen molecules from being absorbed. In effect, the body suffocates.

6. Does Everyone React to Carbon Monoxide?

The short answer is - NO. The harmful effects of CO depend on exposure time, concentration of gas, age, health, body size, lung characteristics and probably a hundred other criteria.

A room full of people exposed to carbon monoxide will have a variety of reactions. Most will get headaches, some will be nauseous, a few will become dizzy and some folks will become visibly weak and confused. Some folks will show no effects at all.