Carbon monoxide is a colorless, odorless, tasteless gas (chemical formula CO) that is produced when fuels like gasoline, natural gas, wood, charcoal, or oil burn without enough oxygen (incomplete combustion).

What is carbon monoxide?

  • A toxic gas made of one carbon atom and one oxygen atom (CO).
  • It is invisible and you cannot smell or taste it, which makes it especially dangerous.
  • It is created by burning carbon-based fuels: gasoline, natural gas, propane, wood, coal, charcoal, oil, kerosene, and similar materials.

Common everyday sources include:

  • Car and truck exhaust
  • Gas stoves and ovens
  • Furnaces, boilers, and water heaters
  • Fireplaces, wood stoves, space heaters
  • Generators and other fuel-powered tools

Why is carbon monoxide dangerous?

When you breathe in carbon monoxide, it enters your bloodstream and binds to hemoglobin (the molecule that carries oxygen in your blood), forming carboxyhemoglobin.

This blocks your blood from carrying enough oxygen to vital organs like the brain and heart, which can quickly become life‑threatening.

Even at relatively low levels, carbon monoxide can cause health problems, and at higher levels it can lead to loss of consciousness and death within minutes.

Symptoms of carbon monoxide poisoning

Early symptoms often look like the flu but without a fever.

Typical signs include:

  • Headache
  • Dizziness or lightheadedness
  • Weakness or fatigue
  • Nausea and vomiting
  • Shortness of breath
  • Confusion or trouble thinking clearly

At higher exposures:

  • Chest pain, especially in people with heart disease
  • Blurry vision or loss of coordination
  • Loss of consciousness
  • Death, if exposure continues

One key warning sign: people and pets in the same space feeling sick at the same time, especially when using fuel-burning appliances.

Where does carbon monoxide build up?

Carbon monoxide becomes dangerous when it accumulates in enclosed or poorly ventilated spaces.

Risky situations include:

  • Running a car in a closed or attached garage
  • Using generators, charcoal grills, or camp stoves indoors or near windows/doors
  • Using gas ovens or stoves to heat a home
  • Blocked or damaged chimneys, flues, or vents
  • Faulty furnaces, water heaters, or space heaters

Quick safety basics

  • Install carbon monoxide alarms outside sleeping areas and on every level of your home.
  • Never run vehicles, generators, or fuel-powered tools inside a garage or home, even with doors open.
  • Keep chimneys, vents, and flues clear and have fuel-burning appliances serviced regularly.
  • If a carbon monoxide alarm sounds or you suspect CO: go outside to fresh air immediately and call emergency services.

Simple HTML table of key facts

html

<table>
  <tr>
    <th>Aspect</th>
    <th>Key Details</th>
  </tr>
  <tr>
    <td>What it is</td>
    <td>Colorless, odorless, tasteless gas (CO) produced by incomplete combustion of carbon-based fuels. [web:1][web:3][web:5][web:7][web:9]</td>
  </tr>
  <tr>
    <td>Main sources</td>
    <td>Vehicle exhaust, gas stoves/ovens, furnaces, fireplaces, wood stoves, generators, fuel-burning heaters and tools. [web:1][web:3][web:5][web:7][web:9]</td>
  </tr>
  <tr>
    <td>Why dangerous</td>
    <td>Binds to hemoglobin, reducing oxygen delivery to organs; can cause illness, brain damage, or death. [web:1][web:3][web:5]</td>
  </tr>
  <tr>
    <td>Common symptoms</td>
    <td>Headache, dizziness, weakness, nausea, shortness of breath, confusion; at high levels, loss of consciousness and death. [web:1][web:2][web:3][web:5][web:9]</td>
  </tr>
  <tr>
    <td>Prevention</td>
    <td>Install CO alarms, maintain appliances, ensure good ventilation, never run engines or grills indoors or in garages. [web:6][web:7][web:9][web:10]</td>
  </tr>
</table>

TL;DR: Carbon monoxide is an invisible, odorless poisonous gas from burning fuels that blocks oxygen in your blood, can cause flu-like symptoms, and can be fatal without alarms and good ventilation.

Information gathered from public forums or data available on the internet and portrayed here.