SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/sport-carbon-monoxide

Carbon monoxide from engine exhaust has what color and odor?

It is colorless and odorless, and tasteless too.

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  1. Pale yellow, smells like gas
  2. Slightly green with a sweet smell
  3. Colorless and odorless ✔

Why: Carbon monoxide is a colorless, odorless, tasteless gas in exhaust fumes. You can't sense it, so a leak can go unnoticed unless a detector warns you.

Huh, didn't know that: Most heaters in light aircraft work by air flowing over the exhaust manifold, so a cracked manifold can leak CO into the cabin.

The dad joke
Carbon monoxide is the ultimate ghost: you never see it, hear it or smell it.
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References

Answer: Colorless and odorless. Carbon monoxide is a colorless, odorless, tasteless gas in exhaust fumes. You can't sense it, so a leak can go unnoticed unless a detector warns you.

  1. FAA AIM 8-1-4 Carbon Monoxide Poisoning in Flight www.faa.gov/air_traffic/publications/atpubs/aim_html/chap8_section_1.html
    Carbon monoxide is a colorless, odorless, and tasteless gas contained in exhaust fumes.
    Checked 2026-10-10.
  2. FAA AIM 8-1-4 Carbon Monoxide Poisoning in Flight www.faa.gov/air_traffic/publications/atpubs/aim_html/chap8_section_1.html
    Most heaters in light aircraft work by air flowing over the manifold.
    Checked 2026-10-10.

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