Understanding the vaping-vs-smoking comparison starts with one word: combustion.
When a cigarette is lit, tobacco burns at 600-900°C (1,100-1,650°F). This combustion produces:
- Tar: A sticky mixture of hundreds of chemicals that deposits in the lungs, causing cancer, COPD, and emphysema
- Carbon monoxide (CO): A poisonous gas that binds to hemoglobin, reducing oxygen delivery to organs
- 7,000+ chemical compounds: Including 70+ known or probable carcinogens (benzene, formaldehyde, nitrosamines, polonium-210)
- Particulate matter: Microscopic particles that penetrate deep into lung tissue
Vaping devices heat e-liquid at 150-300°C (300-570°F) — well below combustion temperature. No tobacco burns. No tar forms. No carbon monoxide is produced. The aerosol contains:
- Nicotine (in most e-liquids)
- Propylene glycol (PG) and/or vegetable glycerin (VG) — the base liquids
- Flavoring compounds (food-grade, but inhalation safety is still being studied)
- Trace levels of some compounds also found in smoke (formaldehyde, acrolein) — but at levels 90-99% lower
The key insight: The danger of smoking comes primarily from combustion products, not from nicotine. Vaping eliminates combustion. This single fact is the foundation of the PHE 95% finding. For more on what's actually in vape aerosol, see our e-liquid ingredients science guide.
