Acetaldehyde
The hangover compound from alcohol — and the silent addiction enhancer.
At a glance
- Also known as
- Ethanal · Essigaldehyd
- CAS number
- 75-07-0
- Toxicity
High
- Carcinogenic
- Yes — IARC Group 2B
- In cigarette smoke
- 400-1400 μg per cigarette (DKFZ)
- In vape aerosol
- significantly elevated with sucralose-sweetened liquids
What is Acetaldehyde?
Acetaldehyde is a short-chain aldehyde formed during the combustion of organic substances and during the breakdown of alcohol in the body. The IARC classifies acetaldehyde alone as Group 2B („possibly carcinogenic“), but in connection with alcoholic beverage consumption as Group 1. It's one of the most abundant substances in cigarette smoke — exceeded by quantity only by water, CO, and CO₂.
Why is Acetaldehyde in cigarettes?
Acetaldehyde forms when tobacco sugars, cellulose and added flavouring substances burn. Each cigarette delivers 400 to 1,400 micrograms of acetaldehyde into the mainstream smoke — making it one of the most abundant carcinogens by mass (source: DKFZ). In vape aerosols, especially with sucralose-sweetened liquids, significant concentrations are also measurable.
What Acetaldehyde does to your body — short term
Acetaldehyde irritates the upper airways similarly to formaldehyde but is on average less acutely noticeable. More important than the direct irritation is its addiction-relevant component: acetaldehyde measurably amplifies nicotine's effect on the reward system and makes tobacco consumption additionally addictive. Animal studies show that nicotine and acetaldehyde together act significantly more addictively than nicotine alone.
What Acetaldehyde does long term
Chronic acetaldehyde exposure raises the risk of cancers in the upper aerodigestive tract — oral cavity, throat, oesophagus. This same damage mechanism explains why simultaneous consumption of tobacco and alcohol multiplies cancer risk: both substances deliver acetaldehyde, attacking the same tissues. At the molecular level, acetaldehyde forms DNA adducts and blocks repair mechanisms.
Where else do you know Acetaldehyde from?
Acetaldehyde is what gives you a hangover after too much alcohol — the liver breaks ethanol down to acetaldehyde first, then to harmless acetic acid. Industrially, acetaldehyde is used for plastics, solvents and perfume compounds. In some foods it's added as artificial fruit flavouring.
How it compares
The workplace exposure limit for acetaldehyde is 91 mg/m³ (50 ppm, DFG MAK) — comparatively high because acute toxicity is low. The long-term cancer-relevant exposure from smoking works through a different mechanism the workplace limit doesn't protect against.
Workplace exposure limit: 91 mg/m³ (50 ppm, DFG MAK)
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