The Secret Carbon

Whether it is hot or cold outside, the inside of your car is never comfortable when you first get inside. It is common practice then to leave one’s car running for a minute or two, just to make conditions more bearable. Most people are unaware, however, that a few minutes is all it takes for the concentration of carbon monoxide within a garage to reach unexpectedly high levels….even if the garage door has been left open! This gas is both colorless and odorless, and can take us by surprise.

What is CO, and how is it harmful?

Carbon monoxide (CO) is one of the six major air pollutants that are regulated in many parts of the world. It is a colorless, odorless, tasteless, and highly toxic gas that is produced by the burning of fossil fuels, wood, and even tobacco!

When too much combustion fume is inhaled, CO begins to build up in your bloodstream. Carbon monoxide will prevent oxygen from reaching your organs and tissues, leading to major tissue damage and even death.  

Below are the symptoms felt at each level of CO exposure, expressed in parts per million (PPM)

CO Levels.JPG

The Occupational Safety and Health Administration (OSHA) states 50 PPM is the maximum allowable concentration of continuous exposure for adults over an 8-hour period.

How are we exposed in our homes?

Most CO related deaths occur inside of the home.

Common household fuel appliances are ovens, stoves, fire places, water heaters, and free standing or wall heaters; these are the primary cause of fatal CO exposure if not properly maintained.

Carbon Monoxide .jpg

Because CO is colorless and odorless, people may begin to feel dizziness, nausea, headaches, weakness, and blurred vision with no apparent cause. If the home is not equipped with a CO detector, a homeowner may not be aware of fumes being released into the home creating a deadly situation.

 Some tips for homeowners:

·         Have fuel burning appliances checked each year

·         Have CO detectors installed to give warning when CO levels are too high

·         Place back-up power generators outside of the home, at least 20 feet from the windows and doors.

·         Don’t use kerosene space heaters or lamps inside of the home

·         Do not leave a fire blazing in a fireplace

·         Charcoal grills and camp stoves should only be used outdoors

·         Make sure to have your car’s exhausts system inspected each year

·         Do not leave a vehicle running in the garage, even if the door is open

Leave the home immediately if you being to feel any symptoms that may be related to CO exposure.

How does the government get involved?

Similar to homeowner’s checking and maintaining the air quality of their home, the States also have regulations for CO exposure. Through the Clean Air Act the EPA monitors and evaluates the CO levels of the outdoor air in each State. Data from designated areas help agencies make sure that the CO levels in the air are kept within the acceptable range. Each state has an obligation to show a course of action on how they will reduce CO and other air emission sources in their State Implementation Plan (SIP).

Latitudes Environmental is a full-service consulting firm, practicing in indoor air quality and industrial hygiene



(1)    CO Health Risks - Detect Carbon Monoxide. (2019). Retrieved from

(2)    Applying or Implementing the Outdoor Air Carbon Monoxide (CO) Standards | US EPA. (2019). Retrieved from

(3)    Carbon Monoxide. (2019). Retrieved from

(4) Carbon monoxide poisoning - Symptoms and causes. (2019). Retrieved from

David Lewis