Yeah as far as I know it is fine, aslong as you are not in a small space with the fumes being really overpowering, one thing to keep in mind and I am sure your hairdresser would know and do this is to keep a close eye on the colour while processing as pregnancy can make things react differently especially things like our hair, I mean before i had any children my hair was very fine and dead straight after 2 children is mega thick and has a slight curl go figure huh LOL, but really you should be fine as long as your haidresser is aware that you are or may be pregnant.