Ok so I know dying your hair etc isn't advised during pregnancy but some other articles reccomening not using other chemicals such as salicylic acid (used in acne meds, cleansers and toners etc) but how about benzyl salicylate? This is found in hair conditioners, foundations and other beauty products. It's a chemical that is part of salicylic acid that are shown not to be safe, its also in the new cussons mum and me pregnancy conditioner.
Yeah well you'd assume so but there is research to show that it may just not be safe as its not really tested during pregnancy. I'm probably being over cautious but I do think it should be clear as to what can be used during pregnancy as there aren't really any official guidelines like there are with food.
I think you could drive yourself mad worrying about every single chemical you come into contact with. Nothing is 'tested' for use in pregnancy because they wouldn't be able to get ethical approval for the trials. But if it's a common household chemical which is used by millions of pregnant women every year, then the risks would almost certainly be known.
Just avoid the things which are known to be harmful (smoking, excessive drinking) and try to relax
If you don't want to use chemicals on your hair why not try henna?
You will find very little that has been scientifically proven to be safe in pregnancy as ethically they cannot do trials on pregnant women. If a product is designed to be used by pregnant women, it will be deemed as safe as it can be using the knowledge at the time. Please try not to worry about every chemical, you'll drive yourself mad with anxiety. The best thing you can do is stick to products that have been around a long time and/or designed for use in pregnancy, and use sensible precautions (open windows if using cleaning products etc.)