To Dye or Not to Dye?

To Dye or Not to Dye?

The concept for Arey came about when our co-founder started to see some grey hair pop up and realized the only solution that existed was a reactive one- hair dye. Considering that hopping on the hair dye wagon would cost lots of time and money, she wanted to delay going down that road as long as possible. Around the same time, she discovered a 2019 NIH Article linking hair dye and chemical straighteners to an increased risk of breast cancer- and had even more reason to create an alternative, safer option for slowing grey hair growth.

We think it’s critical to have an open dialogue about aging hair, as you are likely not alone in spotting your first greys (It happens to 74% of people between 45-65). With so many new scientific reasons to see grey hair as a message from the body, we're here to respond with a proactive, educated approach. We created Arey to offer an alternative to hair dye that until now didn’t exist, but at the same time fully support that some people are still going to make their own risk/reward decision, and opt to color over their greys. 

Below, we outline some information and resources to help you make your own informed decision. 

Permanent hair dye contains numerous chemicals, including high concentrations of oxidizing agents relative to semi-permanent and temporary dyes. In the NIH study, temporary dye was not associated with breast cancer risk, nor was semi-permanent dye if applied professionally (there was an association with non-professional application). At-home kits contain gloves, but potential absorption into the hands and scalp from over-application or over-processing is likely. Residual agents remaining on surfaces or in the air in poorly ventilated settings can also introduce over exposure.

There are up to 400 compounds commonly used in hair dyes that are harmful.  Below are three you should be aware of:


PPD -  PPD or P-phenylenediamine or Para-phenylenediamine is a coal-tar derivative which is allergenic, mutagenic and highly toxic. For more details about PPD you can read here. For 125 years PPD has been the extent of hair dye technology and beauty manufactures have yet to accept a permanent hair-color formula without PPD or its related compound, p-aminophenol. To permanently change the color of hair, a product must be able to penetrate the cuticle to deposit or remove color in the cortex and these chemicals do this. 

Resorcinol - Resorcinol is commonly used in hair dyes and acne medication. In higher doses it is toxic and can disrupt the function of the central nervous system and lead to respiratory problems. It has also been shown to disrupt the endocrine system, specifically thyroid function.

Ethanolamine: All permanent hair colors have to contain an alkaline chemical that opens up the hair cuticles so hair dyes can penetrate and adhere to the hair.  Ammonia does that. When ammonia is not used, typically ethanolamine is used instead.

According to the FDA, ethanolamine may also be contaminated with diethanolamine (DEA), which is linked with cancer in lab animals.  In fact, ethanolamine is rated 5-6 depending on usage (10 being the most toxic) in the Skin Deep database, while ammonia is rated 4-6. So in this case, according to the EWG database, replacing ammonia with ethanolamine may be even more toxic.

There is also limited evidence that ethanolamine is a teratogen in animals. The New Jersey Department of Health states that “[u]ntil further testing has been done, it should be treated as a possible teratogen in humans.”  (source)  (Teratogens are chemicals that interfere with fetus development.)

There is some indication that ethanolamine damages the hair more than ammonia. In this study, researchers applied different methods to measure hair cuticle damage and protein loss and found that there is more hair damage from ethanolamine than from ammonia; in some extreme cases as much as 85% more.

Furthermore, this study found that hair colors that contain ethanolamine versus ammonia are more likely to cause hair loss.

The only improvement is that ethanolamine might not smell as strongly as ammonia.

The European Scientific Committee on Consumer Safety (SCCS) has classified 110 hair colorant chemicals into extreme, strong, and moderate sensitizers.  This is one of the main factors used in the Permanent Hair Color Rating List e-book.  So if you are interested in reducing the risks of allergic reactions, please check out the rating list.

We recommend consulting your local hairstylist before proceeding with any at-home color treatment, since these professionals are well educated on chemicals and how to safely apply them.