Phenol

What is Phenol?

Phenol (hydroxybenzene, carbolic acid) is a crystalline compound with a characteristic sweet-medicinal smell. It was one of medicine's first antiseptics — Joseph Lister revolutionised surgery in 1867 with phenol sprays. Today it's a raw material for phenolic resins (Bakelite, particleboard adhesives) and pharmaceuticals. The IARC classifies phenol as Group 3, but in combination with other substances it acts as a documented cancer promoter.

Why is Phenol in cigarettes?

Phenol forms during pyrolysis of plant phenols and amino acids in tobacco — closely related to catechol and hydroquinone. Each cigarette delivers 60 to 140 micrograms of phenol into the mainstream smoke (source: DKFZ). In smoke, phenol acts less as a standalone carcinogen than as a promoter — it significantly amplifies the DNA-damaging effect of benzo[a]pyrene and other polycyclic aromatics.

What Phenol does to your body — short term

Acutely, phenol irritates eyes, airways and skin. At the low amounts from a cigarette, no perceptible acute symptoms are expected. On direct skin contact — for instance in industrial production — phenol causes burns and can be absorbed systemically through the skin, with neurological symptoms (dizziness, nausea) at higher doses.

What Phenol does long term

Chronic phenol exposure leads to persistent airway irritation and mucosal changes. The central effect documented in tobacco research is the promoter function: phenol itself doesn't trigger tumours, but it accelerates the growth of already-initiated tumour cells. Mouse studies show phenol applied to skin amplifies the carcinogenic effect of benzo[a]pyrene by a factor of 3 to 10.

How it compares

Germany's workplace exposure limit for phenol is 8 mg/m³ (2 ppm, AGW TRGS 900). The amounts per cigarette fall well below this — phenol's importance in tobacco smoke lies not in acute toxicity but in promoter-like amplification of other substances' carcinogenic effects.

Workplace exposure limit: 8 mg/m³ (2 ppm, AGW TRGS 900)