Natural dyes are growing in popularity, both at home and in salons.

People who wish to avoid allergenic chemicals in hair dye should not always trust advertisements promising gentle products that condition hair.

Cosmetics expert Päivi Kousa of the Helsinki Allergy and Asthma Association says the marketing of hair colour products in Finland can be colourful in more ways than one.

“Allergenic hair dyes can be promoted as having undergone testing supervised by a dermatologist, which can really mislead the consumer,” she says.

How to use hair dye safely

• Do not dye your hair more than once every eight weeks.

• Do not colour all of your hair each time. Use temporary colour occasionally or do streaks. Choose plant-based dyes.

• Dye your hair a shade that is close to your own hair colour. That way you can take more time between colourings.

• Colour with oxidants is not recommended for people under 16 years of age.

• An allergic reaction can include itching, swelling, a rash or sores. Sometimes, a small amount of itching can continue for decades before serious symptoms, for others a serious reaction develops immediately. If you notice a reaction, do not continue to dye your hair with colours containing paraphenylenediamine or its derivatives.

• Do not get black henna tattoos, as they can cause increased susceptibility to hair-colour allergies.

The most common ingredients to cause an allergic reaction in hair dye are paraphenylenediamine and its derivatives. However, hair dye may be advertised as ammonia-free, for example, although according to Kousa, ammonia content is not a significant factor when it comes to the risk of an allergic reaction.

“If the colour contains less ammonia, another alkaline ingredient must be used in order to open the hair shaft. The other alkaline agent used, ethanolamine, is actually a bit more irritating to skin than ammonia.”

Kousa feels that hairdressers should also be more aware. “Hairdressers have a huge responsibility to make sure that hair colour is not applied too often, to a broken scalp or to a customer who is too young. I don’t know of anyone who has been asked by their hairdresser if their scalp feels itchy.”

When it comes to safety, there is really no difference between the hair dyes used by hairdressers and those sold in supermarkets. All semi-permanent and permanent dyes containing oxidising agents belong to the same class.

According to Kousa, people can avoid allergic reactions by using more common sense when dyeing their hair, for example by dyeing it less frequently and by not always dyeing all of the hair.

Retailers and importers responsible

Researcher Anna Pukander of the Finnish Safety and Chemicals Agency Tukes remarks that there is a fine line between misleading and accurate advertising in the cosmetics industry. It is the responsibility of Tukes to get involved if advertisements endanger the safety of consumers, whereas the Consumer Agency is responsible for ensuring that advertisers follow the rules of the game.

Tukes has not been contacted thus far by customers regarding hair colour advertising, but they have been contacted by hairdressers.

In unclear situations, Pukander encourages customers to contact the retailer or importer, who are responsible for product safety and correct packaging information.