According to Al-Nisa Ward, a cosmetic chemist and president and owner of Cosmetic Science and Innovation, there are several chemicals you want to avoid completely, but others depend on your hair type. Some haircare products and cosmetics contain MEA, TEA and DEA, which are known to cause cancer. Originally used to increase the viscosity of shampoos and conditioners, Al-Nisa says there have been several instances where ethanolamine compounds (the name of this chemical group) cannot be processed by the liver. As a result, Safe Cosmetics.org says there are several cases where these chemicals have led to liver tumors.
"Also avoid preservatives that are formaldehyde releasers, such as Diazolidinyl Urea and DMDM Hydantoin," Al-Nisa told us. Formaldehyde releasers have been known to cause allergic reactions in users, and almost 20 percent of U.S. cosmetics and personal care products contain this ingredient.
For other chemicals, the way your hair reacts depends mostly on your hair's texture.
If your hair is drier or you apply heat to your hair during your styling routines, you're going to want to avoid alcohol-based products.
"You want to use a gentle shampoo and avoid using sulfates because they are harsher," Al-Nisa said. Also, be sure to check the contents of your styling products because many gels and hairsprays are also alcohol-based, which can further dry out your hair. Moisturizing creams and conditioners with lighter weight formulas will help to reduce dryness in your hair overall.
For oily hair, Al-Nisa says the rule of thumb is to go heavy on your shampoo but light on the conditioner. Thoroughly shampooing will help to get rid of unwanted oil excess, and a lighter conditioner formula will prevent your hair from retaining oil. Lighter formulas for styling products is also ideal because similar to conditioner, it will not weigh your hair down. Unlike dry hair, you don't have to avoid alcohol-based products completely, but since some can be very drying, be mindful of how much and how often you use them.
As far as whether to avoid sulfates, that depends on your preference.
Thick, Coarse or Curly Hair
If you're concerned about any of the other chemicals in your hair products, the Environmental Working Group has a database called "Skin deep" that allows you to search the chemicals in your products to learn more about them. They will give you a comprehensive overview of how many products use the chemical, and whether or not the chemical is potentially harmful to you or to the environment. Because most chemicals in our favorite products are not as regulated as the things that go into our food, the EWG is a perfect source to find out more details about the products you are using.