Healthy skin centre

Hair dye FAQs

What precautions should I take when I dye my hair?

You should follow these safety tips when dyeing your hair:

• Don't leave the dye on your head any longer than recommended
• Rinse your scalp thoroughly with water after use.
• Wear gloves when applying hair dye.
• Carefully follow the directions in the hair dye package.
• Never mix different hair dye products.
• Do a patch test for allergic reactions before applying the dye to your hair. Almost all hair dye products include instructions for doing a patch test. It's important to do this each time you dye your hair. Your hairdresser should also do the patch test before dyeing your hair. To test, put a dab of hair dye behind your ear and don't wash it off for two days. If you don't have any signs of allergic reaction, such as itching, burning, or redness at the test spot, you can be more confident that you won't have a reaction to the dye applied to your hair. If you do react to the patch test, do the same test with different brands or colours until you find one to which you're not allergic.
• Never dye your eyebrows or eyelashes. An allergic reaction to dye could cause swelling or increase risk of infection in the eye area. This can harm the eye and even cause blindness. Spilling dye into the eye by accident could also cause permanent damage.

Are hair dyes safe?

The decision to change your hair colour may be a hard one. Some studies have linked hair dyes with a higher risk of certain cancers, while other studies have not found this link. Most hair dyes also don't have to go through safety testing that other cosmetic colour additives do before hitting the market. Women, and men, are often on their own trying to determine whether hair dyes are safe.

In 2008, the International Agency for Research into Cancer (IARC) said that hairdressers "probably" have a slightly higher risk of developing cancer because they are regularly exposed to certain chemicals. They can reduce their exposure to these chemicals by wearing gloves. But there’s not enough evidence to say whether people who use hair dyes themselves have a higher risk of cancer as a result.

Cancer Research UK advises "If you use hair dyes and are concerned about cancer, you could reduce your use or switch to lighter shades or semi-permanent types. These contain lower levels of chemicals than darker, permanent dyes."

When hair dyes first came out, the main ingredient in coal-tar hair dye caused allergic reactions in some people. Most hair dyes are now made from petroleum sources.

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

Hair dye manufacturers have stopped using things known to cause cancer in animals. For example, 4-methoxy-m-phenylenediamine (4MMPD) or 4-methoxy-m-phenylenediamine sulfate (4MMPD sulfate) are no longer used. But chemicals made almost the same way have replaced some of the cancer-causing compounds. Some experts feel that these newer ingredients aren't very different from the things they're replacing.

Experts suggest that you may reduce your risk of cancer by using less hair dye over time. You may also reduce you risk by not dyeing your hair until it starts to grey.