My ‘Natural’ Hairdresser Uses Synthetic Chemicals. Can I Leave a Bad Review?

I’ve been going to a hairstylist who promotes his all-natural, organic dye as healthy for hair. I never questioned it, until at my most recent visit he dyed my hair the wrong color. When I asked him to fix it, he made it even worse, turning my hair a deep mahogany instead of the golden copper I requested. For two weeks he repeatedly insisted, via text, that he had done it correctly, and that I didn’t know what I wanted. His rude, angry responses made me too uncomfortable to ever return. Frustrated, I researched the dye brand he used and was horrified to learn that its key ingredient, ethanolamine, is potentially more damaging to hair than ammonia, and I’ve read that it could be carcinogenic.

Now I’m torn. My hairstylist refunded my money, and I sympathize with him as a small-business owner, but I also feel compelled to warn people that his “healthy” dye may not be as safe as he claims. Am I obligated to speak up, or should customers be responsible for doing their own research? Would posting a negative review protect others or punish him by potentially putting his small business at risk? What’s the right thing to do? — Name Withheld

From the Ethicist:

I understand why you’re feeling torn. You don’t want to jeopardize someone’s livelihood over a disappointing experience, but you also feel a responsibility to speak up if others might be misled. Two key questions are whether your stylist knowingly misrepresented the product and whether it really poses health risks.

It’s entirely possible he genuinely believed what he was saying. Companies often use carefully crafted language to make their dyes sound especially “natural.” Naturtint, for example, highlights its U.S.D.A. BioPreferred certification and touts “botanical-inspired formulas.” Aveda describes its hair-color line as “vegan.” Both brands still contain industrially synthesized chemicals. (Yes, chemists classify most carbon-containing compounds as “organic,” but that’s not how marketers use the term.) Your stylist may simply be parroting what the product reps told him.

When it comes to safety, precision matters. Ethanolamine-based dyes may not be as gentle as their marketing suggests — some studies do indicate they can weaken hair more than ammonia does. Still, they’re far less harsh than the all-natural potash or slaked lime our ancestors once used. Like ammonia, ethanolamine helps open the hair cuticle so color can penetrate. It’s also a normal product of our body’s metabolism, though it’s industrially produced for commercial use. While it shouldn’t be combined with substances that can form harmful nitrosamines — a risk reputable brands are careful to avoid — ethanolamine is not classified as a carcinogen.

Which brings us to your dilemma. If you do write a review, focusing on your personal experience — the color errors and how the stylist responded — would be the fairest and most helpful approach. There’s no clear legal definition of “natural” for cosmetic products; the status of ethanolamine is complicated; and unless you feel confident explaining it clearly, it may not be the most relevant detail to include.