This is tricky. Hair dye is toxic but ... it's hair colour, and how are we supposed to get our hair looking good without it?
First the bad news:
Formaldehyde
The worst chemical in hair products is of course Formaldehyde which is on the World Health Organisation's carcinogen list and is found in some keratin treatments and nail polish. They generally don't use it in shampoos and conditioners any more and it is banned in hair products in Australia. But do be warned if your hair product is from another country eg. Brazil, who do allow it.
PPD
The other main one to watch out for is p-Phenylenediamine more commonly known as PPD. This is prolific in hair colour. And it's the one that has been linked to cancer and lung and kidney problems. A 2001 study found that those who dye their hair once a month had an increased risk of bladder cancer which increased the longer the hair dye was used.
And it's worse in dark hair dye, so brown and black hair colour have a stronger PPD proponent.
Coal Tar
A known carcinogen and in hair colour and anti-dandruff shampoos and conditioners - avoid it!
Resorcinol
Super common in hair dyes and a known endocrine disruptor.
Ammonia
Can cause respiratory problems and asthma.
Clean hair dye
I've been on the hunt for a non-toxic brown hair dye for years, and I still haven't found the perfect one unfortunately - but we're close, so close. The henna-based products in health food stores leave hair a reddish brown (which I LOATHE on me) but if that works for you then go for it.
Aveda (which I thought would be my saviour) doesn't contain Ammonia but it still contains the worst ingredient, PPD, so that's not actually a clean hair dye and still toxic.
I've tried many other at home "organic" hair colours and my hair always comes out a reddish-brown. UGH.
HOWEVER.
I have recently been colouring at an Original & Mineral salon.
They are completely natural products, no PPD, no Resorcinol, and they literally don't even smell so you know how sometimes your eyes water at the hairdresser's? Not with this product. And they miraculously don't make my hair reddish brown. I am still trying to find the perfect shade which covers my greys and is more on the ash-side of brown. I think my hair is quite difficult to colour though, and still highly recommend them.
If you prefer to colour at home, there is a natural colour company called The Shade, which delivers to your door on a rolling subscription. I tried them a few times but found even though I ordered Ash Brown, my hair still came out reddish-brown and it didn't completely cover the greys around my hair line which are bloody stubborn. Still, they are the best of the home hair colours I have tried. And if you have less stubborn hair that doesn't want to be red even though I don't want it to be red, you may have more luck with this brand.
Highlights
I'm due for highlights in a few months, and for this I will use regular bleach products. Here's why:
1. Your hair is dead, so anything that doesn't go on your scalp will not get into your bloodstream. This is my general "clean beauty" rule. If it touches your skin, avoid it. If it doesn't - ie. on your hair, you have more leeway.
2. I don't have a reaction to ammonia/bleach apart from hating the smell.
3. Because my hair is just aching to go red, when I do highlights this can translate as orange - even worse on me than red. But with bleach products they can make my hair go exactly the shade of caramel I'm after.
4. I only do highlights once a year. So it's like the 80/20 rule, except this is more 99/1.
5. The brown hair dye I'm actually using on my scalp is all-natural and non-toxic. This is what I do monthly and what will have the most impact on my health, so that is a non-negotiable, it has to be a clean product. Just like my natural perfume.
P.S. Jessica Alba is my current hair colour inspo. Golden brown, not red! Who's yours?