"It takes courage to grow up and become who you really are."— e. e. cummings

Growing up involves "individuation," which is the process by which individuals in society become…well, individuals! For today's teens, this often means arrowed eyes or smoky eye shadows, deep blue, gray, green or amethyst eye irises, or pastel, neon, rainbow or denim hair. As parents we should know about the potential health issues related to the products our teens are using.

Turns out what you don't know can hurt you. If a cosmetic has caused harm to a consumer, manufacturers are not required to share this information with the U.S. Food and Drug Administration. In 2014, after directly receiving 127 customer reports of problems caused by a certain shampoo and conditioner, the FDA opened an investigation. As a result of this case, in 2016, the FDA's Center for Food Safety and Applied Nutrition made a database for adverse event complaints available to the public. The result: Complaints related to cosmetics more than doubled between 2015 and 2016, according to a study cited online on June 26 in JAMA Internal Medicine. Hair care products received 35 percent of the complaints in the database followed by 22 percent for skin care products. Most health issues involved rashes and hair loss. More serious illnesses such as cancer or severe allergic reactions were also reported.

Hair today, gone tomorrow. There are three main types of hair dyes:

  • Temporary dyes cover the surface of the hair and last for 1-2 washings.
  • Semi-permanent dyes penetrate into the hair shaft and last for 5-10 washings.
  • Permanent hair dyes cause chemical changes in the hair shaft that last until the hair is replaced by new growth.

In evaluating hair dyes, the FDA determines if there is "a reasonable certainty of no harm." Altogether, the many hair dye products available on the market contain thousands of different chemicals. With the exception of certain colorants, the FDA does not approve each chemical or, for that matter, each ingredient before it goes on the market. Some chemicals in hair dyes can be absorbed through the skin or inhaled from fumes in the air. Some of these are known carcinogens or cancer-causing. Concern about cancer risk is largely limited to the semi-permanent and permanent dyes, and especially darker dyes, which contain more of the chemicals of concern. While some studies have suggested possible links, others have not.

Here's my take:

  • There is a small increased risk of bladder cancer in people who work with hair dyes, such as hairdressers and barbers.
  • More studies are needed.

The FDA has provided some dos and don'ts for consumers applying hair dye:

  • Do pay attention to all "Cautions" and "Warnings" and follow the directions in the package.
  • Do apply the dye to a small area on your arm first to make sure there are no allergic reactions.
  • Do wear gloves.
  • Do thoroughly rinse hair and skin with water after use.
  • Don't leave the product on longer than directed.
  • Don't mix different hair dye products.
  • Don't use on eyebrows or eyelashes. This can cause serious damage, even blindness.

Beauty (but not safety) is in the eye of the beholder. Contact lenses that are used to correct vision require a prescription. Contact lenses that are purely cosmetic (non-corrective and decorative), such as circle contact lenses, also known as big-eye contact lenses, do not require a prescription. Even someone with perfect vision should have an eye examination performed by an eye care professional and get a prescription before any type of contact lenses are put in the eyes, according to the American Academy of Ophthalmology.

Even under the best supervision, injuries and infections can still occur. Non-prescription contacts can cause serious injuries such as potentially blinding bacterial infections (keratitis) and cuts (corneal abrasions) and open sores (corneal ulcers) which may require corneal transplants. "Any type of contact lens that can be purchased without a prescription is being sold illegally," according to the Centers for Disease Control and Prevention.

My advice: Parents, pick your battles. Let teens express their individuality with temporary hair dyes, but fight the decorative contact lenses — you won't just be splitting hairs!