top of page
Family and dog sitting on a couch in a cozy living room.

What is Carbon Monoxide?

Often called the silent killer, carbon monoxide is an invisible, odorless, colorless gas created when fuels burn incompletely.

What is Carbon Monoxide?

Carbon monoxide, more commonly referred to as CO, is a highly toxic gas, produced by devices that burn fuels – often found in our everyday lives. Carbon monoxide can’t be seen, smelled, or heard, but can be extremely dangerous to humans. Carbon monoxide is only detectable with an electronic carbon monoxide sensor.


A fuel source can be anything that burns: paper, gasoline, wood, coal, propane, or natural gas. Improperly ventilated appliances and engines, particularly in tightly sealed or enclosed spaces, may allow carbon monoxide to accumulate to dangerous levels.


Carbon monoxide in the air rapidly enters all parts of the body, including blood, brain, heart, and muscles when you breathe. The carbon monoxide binds to hemoglobin in the bloodstream and starves the body and all of its systems of oxygen.

Common Carbon Monoxide Sources

There are carbon monoxide sources all around us, everywhere we go. The first step to protecting yourself is to understand where carbon monoxide comes from in all types of environments.

Sources inside the home:

  • Stoves

  • Ovens

  • Air & Water Heating Systems

  • Boilers

  • Furnaces

  • Fireplaces

  • Clothes Dryers

  • Vehicles in attached garages

Sources at work:

  • Welding equipment

  • Forklifts + manufacturing equipment (LPG fueled, diesel fueled, gasoline fueled)

  • Kitchens

  • Work Trucks

  • Auto Repair

  • Ice Skating Rinks

Sources outside the home:

  • Transportation (cars, boats, trucks, busses, airplanes, RVs)

  • Gasoline-powered engine driven tools (pressure washers, concrete cutters, power trowels, compressors & pumps, lawn equipment)

  • Portable & fixed generators

  • Portable heaters

  • Charcoal & gas grills

Symptoms of CO Poisoning

To avoid carbon monoxide poisoning, the World Health Organization recommends breathing no more than 4ppm over a period of 24-hours. Poisonings come in all shapes and sizes and are classified as acute or chronic

Acute poisoning occurs by breathing large amounts of carbon monoxide over a short period of time. Whereas, chronic poisoning occurs by breathing small amounts of carbon monoxide, over an extended period of time. 

The severity of poisoning and the subsequent symptoms depend on the total amount of carbon monoxide breathed over time, as well as the person’s physiological condition. Once carbon monoxide reaches the bloodstream, it quickly starves the body of oxygen, causing asphyxiation.


It can also cause toxic overload up to several weeks later, which can interfere with fundamental organ and gland functions. 

Early warning signs of carbon monoxide poisoning include:

  • slight headache

  • nausea

  • vomiting

  • fatigue

  • flu-like symptoms

With continued exposure, you will experience:

  • a throbbing headache

  • drowsiness

  • confusion

  • fast heart rate

After prolonged exposure, you may experience:

  • convulsions

  • unconsciousness

  • brain damage

  • heart and lung failure, followed by death

If multiple people in the location begin to experience symptoms like those listed above, this is often a tell-tale sign there is an environmental-health related issue happening on site.

While victims of chronic carbon monoxide poisoning are not at risk of immediate death, they will often face long-term health issues (often unexplained or misdiagnosed) during or after continued exposure. 


One of the most common long-term health issues associated with chronic carbon monoxide poisoning is neurological damage and associated cognitive impairment.


Chronic carbon monoxide poisoning can lead to:

  • impaired attention and problem-solving abilities,

  • mental confusion,

  • difficulty with simple arithmetic,

  • memory impairments,

  • disorientation,

  • depression,

  • disorganized thoughts

  • Parkinsonian symptoms (e.g., tremors)


Brain scans from carbon monoxide poisoning survivors show damage to many different brain regions, including the frontal cortex, hippocampus, and basal ganglia. These regions are thought to play important roles in planning, learning, memory, and movement. 

Signs of acute carbon monoxide poisoning can include: 

Person with a deadache clip art


Person out of breath clip art.


Unconsciousness person Clip Art


Sick person clip art.


Dizzy person clip art


Person falling clip art


Signs of chronic carbon monoxide poisoning can include: 

Person with balloons clip art.

Feeling physically better when not at the site of poisoning

Person in hospital bed clip art.

Lung, heart, & brain damage

Sad person clip art.

Behavior changes & mood disorders

Person with medical IV clip art.

Body system interference

Person with illness clip art.

Reoccurring & unexplained illnesses

Coughing person clip art.

Symptoms related to toxic poisoning

Patient medical checkup with doctor in doctor's office.

Treatments For CO Poisoning

In addition to its known moniker of ‘the silent killer,’ carbon monoxide poisoning can be called the ‘great imitator' because its symptoms closely resemble those of other illnesses. This leads to frequent misdiagnosis, mistreatment, and/or continued poisoning. 

Carbon monoxide poisoning can only be treated (i.e. get carbon monoxide out of a person’s bloodstream) through fresh air, high-dose oxygen through masks or oral equipment, or in severe cases, requiring placing the person in a full-body oxygen chamber known as a HBO2 chamber, though the use and efficacy of HBO2 chambers for carbon monoxide poisoning is somewhat controversial. Doctors can diagnose acute poisoning but, only if an arterial blood test is performed within 2.5-4 hours (ideally < 2 hours) after the poisoning occurs, or with the use of an FDA-approved breath diagnostic tool. 

bottom of page