• Quizzes
• Smoke is Poison
• Smoking and tobacco
• Alcohol
• Diet and healthy eating
• Obesity and weight
• Exercise and activity
• SunSmart
• Body awareness
• Cancer screening
• Signs and symptoms
• Family history
• Hormones
• Harmful substances
• Cancer controversies
  • Mobile phones
  • Power lines
  • Stress
  • Deodorants
  • Pesticides
  • Air travel
  • Hair dyes
  • How do we know?
• How do we know?
• Who do we believe?
• What is risk?
• Worried?
• Reduce the Risk
• Open Up to Mouth Cancer
• Links

Hair dyes and cancer

Hair dyes have been linked to a variety of cancers including bladder cancer, breast cancer, leukaemias and lymphomas. But there is no strong evidence that hair dyes cause any of these.

In the 1970s some hair dye ingredients were found to damage DNA and cause cancer in animals. But since then, the use of these chemicals has been discontinued and modern dyes are thought to be much safer.

Hair dyes now come in different types. While there is still debate about permanent dyes, there is no concern over the safety of semi-permanent dyes that wash out.

Hair dyes and bladder cancer

Studies linking hair dye to bladder cancer risk have been very inconsistent. At the moment, there is not enough evidence to show that permanent hair dyes affect bladder cancer risk. But we can’t completely rule out a risk either.

There is a theory for how hair dyes could increase bladder cancer risk. When you use hair dye, you absorb small amounts of chemicals called arylamines through your skin. We have genes that render arylamines harmless so we can get rid of them through our urine. Along the way, they come into contact with the bladder. But some people may have different versions of these genes, which are not as good at processing arylamines. These people may have an increased risk of bladder cancer if they use hair dyes regularly over a long period of time.

So far, this is just a possible theory and has not been conclusively proven.

Hair dye and other cancers

The evidence linking permanent hair dyes to breast cancer, leukaemias and lymphomas is very weak. Even if there is an increased risk, it would be extremely small.

Taking precautions

If you use permanent hair dyes and are concerned, you could reduce your use or switch to semi-permanent types. The current evidence suggests that short-term or infrequent use of these types poses very little, if any, cancer risk. You may also wish to consider using lighter shades since these contain lower levels of chemicals than darker shades.

In July 2006, the EU Commission announced that it would ban 22 different hair dye substances which do not have adequate safety files. This is a reassuring move for consumers as it means that only dyes that are proven to be safe will be available.

Smoking and bladder cancer

Smoking is the biggest risk factor for bladder cancer, causing half of all cases in men and a third of those in women. If you want to reduce your risk of bladder cancer, the best thing you can do is to not smoke. Tobacco smoke also contains arylamines.