Q&A on Safety
Do hair dyeing products and bleaches (containing persulfates) cause rashes?
In rare cases, some people may get a rash in reaction to the dyes contained in hair dyeing products. Use of bleaches containing persulfates may also result in a rash.
Rashes can be largely divided into two categories: primary irritant dermatitis and allergic contact dermatitis. Primary irritant dermatitis occurs in people with sensitive skin or those whose dermatological “defenses” are weakened, and can arise not only from hair dyeing products but also cleansers and other cosmetics.
Allergic contact dermatitis is, like hay fever or other allergies, an over-reaction of the body’s immune system.
Whether hair dyeing products cause an allergic reaction or not varies by the individual, and it is possible for an allergy to occur suddenly.
Please be aware that if you have ever developed a rash from hair dye or bleach containing persulfates, you should never use it again because you will develop rashes in the future as well.
Always do a patch test before using hair dyeing products regardless of whether it is your first time or whether you have used the product before without incident.