Some young people dye their hair various colors to express their individuality. Older adults may dye gray hair black to appear younger, but the chemicals in hair dye can harm health, so it's best to minimize dyeing frequency.
What health risks does hair dyeing pose?
Dyeing disrupts the hair's moisture balance, reduces protein content, and causes protein denaturation. This makes hair increasingly fragile, prone to breakage, and loses its natural softness and resilience. The more frequently hair is dyed, the more severe the damage becomes.Dyeing hair more than twice a year is not recommended. Hair dyes can irritate hair follicles, potentially causing folliculitis. Long-term use may lead to follicle atrophy, resulting in finer hair strands and increased shedding.Hair dyes may also trigger skin allergies and contact dermatitis. Mild cases present as scalp redness, swelling, itching, and oozing. Severe reactions can manifest as papules or blisters, potentially leading to loosening and necrosis of the hair cuticle. Therefore, a skin test is essential before dyeing. Apply a small amount of the dye to the inner wrist, allow it to air dry, and discontinue use if itching or redness occurs.
Hair dyes contain chemicals like phenol and aniline, which are potent carcinogens. These substances may be absorbed through pores, gradually accumulating in the body where they bind to cells. They can damage DNA, causing normal cells to mutate and potentially leading to skin cancer, leukemia, and breast cancer.Additionally, some metallic hair dyes contain silver nitrate or acetic acid alkali. When absorbed into the body, these can cause chronic poisoning, leading to symptoms like limb numbness, headaches, dizziness, and generalized weakness. If these substances reach the brain, liver, or kidneys, they can pose a serious threat to health and life.
How to dye hair more safely?
Avoid washing hair the day before dyeing, as natural scalp oils protect against harmful substances entering the body. Apply petroleum jelly to hair before applying dye to prevent direct scalp contact.Limit hair dyeing to no more than twice a year. Never mix different brands of dye, as this can cause chemical reactions. Avoid leaving dye on the scalp for extended periods. After dyeing, wash your hair thoroughly multiple times. Do not scratch the scalp during washing, as this may allow chemicals to enter the body.
Friendly Reminder
Avoid repeated dyeing within three months. Keep dye application at least two centimeters away from the scalp. Rinse thoroughly multiple times after dyeing to remove residue. Refrain from vigorously scrubbing the scalp. Choose hair dye products from reputable manufacturers.