Q&A: 10 cancer-related misconceptions

Q: People shouldn't color hair because hair dye is carcinogenic?

A: Hair dye contains "p-phenylenediamine", a chemical substance that may pose a certain risk of cancer only with frequent and excessive exposure. There is no established evidence that qualified hair dye and moderate hair coloring would increase cancer incidence. However, other components in the hair dye, such as hydrogen peroxide, dyes, coupling agents, and certain botanical ingredients, can stimulate the scalp and cause allergies. Frequent hair coloring is also harmful to the hair. Therefore, individuals are advised to buy the hair dye of a qualified brand and do allergy tests before hair coloring, and the hair dyeing interval is best controlled at about 4 months.