Odorless, Colorless Poisons: Controlling Carbon Monoxide and Dioxide in Your Home

Although many gases are colorless, odorless, and tasteless, they can nevertheless be very deadly, especially in high concentrations. Even though an energy efficient HVAC is important, so is your safety and indoor air quality.

Here’s what to watch out for and how to protect yourself and your family.

Source: Flickr Commons


Carbon dioxide, or CO2, is a colorless, odorless gas that’s produced naturally and by man-made processes. In the environment, we exhale CO2, which is then taken up by plants and trees. As a gas, CO2 can vary in concentration from 350-400 parts per million (ppm) or higher in areas where there is a lot of human activity.

CO2 is measured in indoor environments to assess how much outdoor air is entering a room relative to the number of occupants. Ventilation is important because it can dilute contaminants produced in the environment, like odors released from people and contaminants released from building materials and furniture.

CO2 is generally not considered dangerous unless the concentration reaches 10,000 ppm for an 8-hour period or 30,000 ppm for 15 minutes. This is the average concentration for a a localized area.

High levels are extremely rare in non-industrial areas.

If you are poisoned by CO2, you may experience headache, dizziness, nausea, and other related symptoms. These symptoms occur when you’re exposed to levels above 5,000 ppm for many hours over an extended period of time.

Eventually, at a high enough level, you may die from asphyxiation as the CO2 replaces oxygen in your body, though this happens at concentrations around 40,000 ppm.


Source: Flickr Commons

Carbon monoxide is another dangerous gas which is also odorless and colorless, left behind from the incomplete or improper burning of organic substances, like fuels.

It’s dangerous because it interferes with normal oxygen uptake. CO can build up to a dangerous concentration when fuel is burned indoors and the home is not properly ventilated. It has no odor, color, or taste, so it cannot be detected by our senses.
However, it is estimated that 500 deaths occur in the U.S. every year because of unintentional exposure. Poisoning contributes to roughly 2,000 deaths in the U.S. On top of that, the U.S. Consumer Product Safety Commission estimates that between 8,000 and 15,000 people are examined and treated in hospitals for non-fire related CO poisoning.

Fortunately, this is an easy thing to prevent. Common sources of CO include fuel-burning devices like furnaces, gas, and kerosene space heaters, boilers, gas stoves, water heaters, clothes dryers, camp stoves, charcoal grills, wood stoves, fireplaces, and anything with internal combustion engines.

Smoking is another source or CO. Solution: reduce or eliminate your exposure to these sources, and when you must use them indoors, ventilate the home properly.


Radon is another gas that most people don’t think about often, but it’s responsible for 30,000 cases of lung cancer in the U.S. This makes it the leading cause of lung cancer next to smoking.

Companies, like Henscey Electric, however, can help you reduce your risk of exposure by installing ventilation systems and HVAC units that help move air through your home, thus helping to ventilate the house and remove radon gas.

The gas itself is a natural radioactive gas that seeps up through the ground and enters the home through cracks in the foundation and any other openings. Once a home is infiltrated, the best option is to set up a ventilation system to move the radon out of the home.

Rachel Thompson is a contributing health and safety officer and writer for the Green Living Guy. She likes to write about indoor air quality and living healthier on the web. You can find her articles mostly on lifestyle and health websites.

Written by greenlivingguy

The Green Living Guy, Seth Leitman is a green living expert, celebrity and Editor of the McGraw-Hill, TAB Green Guru Guides. Seth is also an Author, Radio Host, Reporter, Writer and a Environmental Consultant on green living. The Green Living Guy writes about green living, green lighting, the green guru guides and more. Seth's books range from: # Build Your Own Electric Vehicle by Bob Brant and Seth Leitman (2nd and 3rd editions) # Build Your Own Plug-in Hybrid Electric Vehicle by Seth Leitman # Build Your Own Electric Motorcycle by Carl Vogel # Green Lighting by Seth Leitman, Brian Clark Howard and Bill Brinsky # Solar Power For Your Home by David Findley # Renewable Energies For Your Home by Russel Gehrke # Do-it-Yourself Home Energy Audits by David Findley # Build Your Own Small Wind Power System by Brian Clark Howard and Kevin Shea # and more green living books to follow.