Protect your family from secondhand smoke

When you stop smoking, you protect your family’s health as well as your own.

When you smoke, it’s not just your health that is at risk. A smoker only inhales about 15% of the smoke from a cigarette - the other 85% goes into the air around you or is inhaled by others.

This is called secondhand smoke. You produce it every time you smoke.

Secondhand smoke includes the smoke you breathe out and the smoke from the lit end of the cigarette.

The smoke contains over 4,000 chemicals, including:

  • arsenic and cyanide - these are both poisons
  • benzene - a chemical that can cause leukaemia

Cancer risks from secondhand smoke

Secondhand smoke contains carcinogens. These are chemicals that cause cancer.

People who breathe in secondhand smoke are at increased risk of smoking-related diseases. For example, non-smoking women who live with someone who smokes are 27% more likely to get lung cancer than non-smoking women who live with a non-smoker.

Opening a window when you smoke does not make a difference. More than 80% of smoke is invisible - you cannot see where it goes or control it.

The risk of secondhand smoke to children

Children are more at risk from secondhand smoke. This is because they breathe more rapidly, and their lungs, airways and immune system are still developing.

Secondhand smoke can increase a child’s risk of:

  • ear infections
  • asthma
  • allergies
  • meningitis
  • cancer
  • bronchitis
  • pneumonia

Babies exposed to secondhand smoke are also at increased risk of sudden infant death syndrome (cot death).

Children who grow up seeing their parents smoke are also 3 times more likely to smoke when they grow up.

Stop smoking to protect your family

You can quit and we can help. Get free support from the Quit programme. Sign up to a personalised quit plan to help you stop smoking.

Page last reviewed: 5 October 2022
Next review due: 5 October 2025