The Food and Drug Administration (FDA) yesterday urged people to purchase only hair dye products approved by the agency and to follow directions carefully to avoid irritating the scalp or causing an allergic reaction.
Sometimes people who have never dyed their hair before do not do a test application and instead randomly apply the product directly to their hair and scalp, running it down their neck and ears, causing redness and irritation, and can lead to skin infection from scratching, said FDA Deputy Director Cheng Hwei-fang (陳惠芳).
Skin irritation and allergic reactions could be avoided by purchasing FDA-approved hair dye products and following the instructions, Cheng said.
Hair dye products are classified as “special purpose cosmetics,” said Chang Chia-jung (張家榮), head of the FDA’s Medical Devices and Cosmetics Division.
Although the agency has issued more than 7,000 permits for hair dyes, containing 104 ingredients, including wax, powder and liquid versions, it has not approved any shampoos for coloring and washing hair at the same time. Chang said.
People should avoid mixing hair dye products because it could cause unpredictable chemical reactions, he said.
The FDA recommends following six steps when dyeing hair at home: Choose products with clear labeling; make sure there are no open sores or abnormal skin conditions on the scalp or surrounding area before application; carefully follow the instructions and safety tips; brush or spread the dye through the hair instead of massaging it into the scalp; pay attention to the condition of the skin after coloring the hair; and wait at least three months before staining it again, he said.
People should not perm their hair in the week before or after coloring it, because dyeing or perming hair can damage the hair cuticle, he said, adding that it is best to perform the procedures at least seven days apart.
Huang Yu-huei (黃毓惠), a dermatologist at Linkou Chang Gung Memorial Hospital, said people should apply a small amount of hair dye behind the ear or elbow crease with a cotton swab to see if it causes an allergic reaction before using hair dye. .
An allergic reaction doesn’t always happen immediately, so people should wait about 48 hours to make sure they are not allergic to chemicals in the product, Huang said.
People with skin disorders such as seborrheic dermatitis or atopic dermatitis should avoid coloring their hair, she said.
Even people who don’t have an allergic reaction to hair dye products should still apply the dye to the hair and not their scalp, she said.
The misconception that dyeing hair causes baldness or gray hair is unfounded because hair dye does not reach the hair follicle, she said.
The FDA recommends wearing gloves and placing a towel on the neck when coloring hair at home, Chang said, adding that people should report adverse reactions from cosmetics, medications, foods or medical devices on the agency’s product quality management website (qms.fda.gov.tw/tcbw).