Chemicals in a Cigarette

Where do all the chemicals come from?

How do so many chemicals end up in cigarette smoke?

Where do all the chemicals come from?

It’s easy to dismiss reports that there are approximately 7000 chemicals in cigarette smoke because it just doesn’t seem feasible. But, sadly, the research is all there.
So how do so many chemicals end up in cigarette smoke?

The tobacco plant

Not all the chemicals in cigarette smoke are present in the tobacco plant, but all plants are composed of chemicals. Plant chemical compounds have roles in plant development, plant reproduction and even defence. In the case of tobacco, nicotine is made inside the plant to act as a pesticide against insects and animals.
Chemicals, including toxins such as lead, nitrates and cadmium, build up in the tobacco plant as it grows and get released when the tobacco in the cigarette is lit and inhaled.


As part of the preparation of tobacco for manufacture into cigarettes, the leaves are dried and cured. The curing process results in the formation of cancer-causing chemicals called tobacco-specific nitrosamines (TSNAs). Other chemicals are added to the tobacco to control moisture, enhance flavour and reduce harshness. Even sugars can be harmful. Natural and added sugars for masking harshness can result in the formation of a cancer-causing chemical called acetaldehyde.

Lighting up

When a cigarette burns, a chemical reaction called combustion occurs. This process reorganises the chemicals found naturally in the tobacco plant into new and more plentiful chemicals. A handful of these harmful chemicals include:

  • carbon monoxide – damages the heart
  • butadiene – affects the reproductive system
  • acrolein – damages the lungs irreversibly
  • benzene – may decrease fertility

More than 70 of the chemicals in cigarettes are cancer causing.

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