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Is Hair Dye "Toxic"? Our Guide To More Natural Hair Color

Alexandra Engler
Author: Medical reviewer:
Updated on April 21, 2023
Alexandra Engler
mbg Beauty Director
By Alexandra Engler
mbg Beauty Director
Alexandra Engler is the beauty director at mindbodygreen and host of the beauty podcast Clean Beauty School. Previously, she's held beauty roles at Harper's Bazaar, Marie Claire, SELF, and Cosmopolitan; her byline has appeared in Esquire, Sports Illustrated, and
Keira Barr, M.D.
Medical review by
Keira Barr, M.D.
Board-certified dermatologist
Keira Barr is a dual board-certified dermatologist and founder of the Resilient Health Institute.

No matter whether you're looking to play with a new look or are aiming to cover up grays, you have every right to experiment with your hair color—but you also have the right to know what's in traditional hair dye formulas1, what the research says, whether there are any better-for-you options out there, and how you can make the coloring process, as a whole, healthier. 

This way, you can make a more informed decision on what's right for you. Here, what to know about hair dye, some myths to bust, and more.

What's found in conventional hair dye?

Every formula is different, so you should read the ingredient label for your particular dye or talk to your colorist about what they use in the salon. And before we dive in, it's good to note that mainstream hair dyes have come a long way in recent years, with less damaging ingredients, smarter formulations (meaning, the questionable ingredients are formulated at much lower levels), and better color payoffs.

"The hardest part of hair color is the balance between limiting the chemicals that have been found to be problematic and still making sure it's effective," says colorist Christine Thompson, co-founder of the hair salon Spoke&Weal, where they offer natural dyes. However, no formula is going to be perfectly clean—that's just not possible with hair dyes at the moment. 

 Here are the main ingredients that come up and what to know about them: 


p-Phenylenediamine (PPD) & other coal tar dyes

This is the one you hear about most often. The pigment is used to darken hair and has been noted as a very strong sensitizer2: Research shows that it can cause contact dermatitis and reactions. As for coal tar dyes in general, the EWG ranks it as a 7 to 10, as studies have indicated it as an irritant and even potential human carcinogen3. The use of the ingredient has been banned by the E.U., and there have been some regulations placed on its use by the FDA4 in the U.S., but not near enough according to many clean beauty experts.

However, Thompson notes that modern formulas have significantly less of these dyes than the past versions. "Back in the day, the color was much different dye than what we use today. You can see the difference: Past hair dyes used to be so opaque and harsh, but now formulas are softer and look much more natural. As we've learned more, we know what molecules we need to minimize and at what concentrations," she says, noting that while many of the hair color formulas still use these dyes, they do so at much lower levels—swapping out the ingredient for safer dyes. 


Formaldehyde and formaldehyde-releasing products

Used as a preservative and stabilizer, these are tricky. Research shows that even trace amounts of formaldehyde are enough to trigger dermatitis in humans5. Few products are going to outright say they contain formaldehyde, yet several preservatives release6 the irritant over time, with temperature variations, or when it comes into contact with other actives. One of those is quaternium-15, which is a common hair dye ingredient. 



Ammonia is a highly alkaline substance, so it is used in hair color to open up the cuticle7. Once the cuticle is lifted, the pigment can be deposited or the lightning agents can lift the color. It's also what gives hair color the strong, overpowering odor. Ammonia is a respiratory and asthma irritant, so the issues arise when you breathe it in through the air. Thompson notes, however, that if you know your formula has ammonia in it, but you can't smell it, that might actually be a bad sign: "That means the product is filled with fragrances to mask the smell—the ammonia is still there," says Thompson. "That's why natural-leaning dyes actually have a more potent ammonia smell—because they're not trying to mask it."

 So can you color your hair safely?

Here's what we know: Hair dyes have come a long way and are much safer8 than the versions of the past. But we also know that the beauty industry is still largely unregulated, and therefore, questionable ingredients are still found in these formulas (yes, even natural dyes). 

So if you want to color your hair safely, it really comes down to how you color your hair. 


Do your research for colorists and color brands.

Beauty stories so often espouse the advice to do your research on hair colorists and stylists (i.e., find one that specializes in redheads or curly hair). The same goes for cleaner hair color. Half of the problem with achieving safer color is that the consumer doesn't even know they can ask for it.

But if you find a knowledgeable colorist—one that works at a natural-leaning, eco-friendly salon, perhaps—they'll be able to walk you through the dyes they're using and what steps they're making to ensure you a better outcome.

And a few color brands offer better-for-you professional formulas, like Aveda and Biolage, so ask your colorist what brands they offer. 


Do it in an area that's well ventilated.

Remember how we said ammonia was a respiratory irritant? Given that, the salon you attend should be well ventilated.

"Some of my clients are very sensitive to the smell, so sometimes we even color their hair outside in one of the salon's gardens," notes Thompson. While this may not be realistic for most salons, you should at the very least find one that has good airflow. 


If you do at-home color, opt for cleaner versions and follow instructions. 

Of course, not everyone can or wants to go to a salon to get their hair colored. If you opt for an at-home color kit, look for a "cleaner" version. For example, the new Revlon Total Color Hair Color Clean & Vegan skips ammonia, parabens, phthalates, silicones, and more. Madison Reed skips PPD, resorcinol, parabens, phthalates, gluten, SLS, and titanium dioxide. 

While you're coloring the hair, be mindful to follow instructions: Wear gloves, follow the time limits, and so on. Oh, and the same goes for ventilation here: Most people probably color their hair in their bathroom, but that likely doesn't have the same airflow. Try the kitchen and open up a window. Check out our favorite at-home dyes here.


 Avoid the scalp.

"Your root, or hair follicle, is a very large opening and a direct pathway to your bloodstream," says trained trichologist and hairstylist Shab Reslan. "So anything you put on your scalp, you're going to be absorbing to some degree." An easy way to avoid the scalp is to opt for a grown-out highlight (luckily, this is trendy).

If you decide to do all-over color, ask that your colorist use foils instead. When a colorist uses foils, they are painting just the strand rather than applying the dye directly to the skin. "I tell my clients that when I use foils, the only exposure they're getting from the dye is through inhalation; you're not absorbing it into the body as it's not touching the skin," says Thompson, and so we'll refer to the ventilation point again. 


 Go longer between appointments 

"The less you're doing it, the less exposure you're going to have," says Thompson. Simply explain to your colorist that you'd like to only come in for appointments every six weeks to even a few months. "A good colorist will be able to work with you to find a look that requires less maintenance."

Another way to prolong hair color is to opt for glosses or glazes in between appointments, as these can color-correct, add depth, and increase shine.


If you have grays, try spot treatment rather than paint all over. 

Grays tend to grow in clusters rather than all over. And if you decide to cover them up, Thompson recommends "spot treating" these clusters rather than painting all over. Not only is it more natural-looking, but it's better for you.

Or, says Thompson, embrace gray. "Often people who have been dyeing their grays for years are scared to transition to gray, not because they don't like the look of gray but because they are afraid of the grow-out process. But there are colorists who specialize in this transition phase who can help you go gray in a really beautiful, natural way."  


Opt for a cleaner, greener salon. 

This isn't just a health issue, hair color residue can affect the environment. When you wash that hair dye out, you may cease contact with it, but that doesn't mean it disappears.

"The EPA reports, a large portion of the world's fresh water resides underground, stored within cracks and pores in the rock that make up the Earth's crust. Half of the U.S. population relies on groundwater for domestic uses as local water waste management can decontaminate only 50% of the water waste. In many parts of the United States, people rely on groundwater for drinking, irrigation, industry, and livestock. This is particularly true in areas with limited precipitation, limited surface water resources, or high demand from agriculture and growing populations. Some ecological systems, such as wetlands or surface waters fed by springs and seeps, also rely on groundwater," says Bill Deliman, the director of business development at Green Circle Salons, a nonprofit organization that educates salons on how to be more eco-friendly (they currently have a partnership with Biolage salons to educate hair stylists and colorists on best practices.)


Tone with natural ingredients.

Let's say you just want a slight tweak to your natural color: A toner might be your best bet. Here's our guide to toning your hair naturally.  

The bottom line.

You deserve to have the full information about what you are putting in and on your body—hair included. From there you can make an informed decision about your beauty routine. Plus, cleaner hair dye is on the rise—and if it's anything like clean skin care and makeup, the increased demand for safer products will likely encourage the market in this direction anyway. 


Alexandra Engler author page.
Alexandra Engler
mbg Beauty Director

Alexandra Engler is the beauty director at mindbodygreen and host of the beauty podcast Clean Beauty School. Previously, she's held beauty roles at Harper's Bazaar, Marie Claire, SELF, and Cosmopolitan; her byline has appeared in Esquire, Sports Illustrated, and In her current role, she covers all the latest trends in the clean and natural beauty space, as well as lifestyle topics, such as travel. She received her journalism degree from Marquette University, graduating first in the department. She lives in Brooklyn, New York.