Are Hair Colours Safe?
All types of readily available, self-applied hair colours are safe to use as long as they have the correct legal safety warnings and directions, and assuming the users observe the safety warnings and follow the directions.
What are the key safety issues with the different types of hair colours?
Semi-permanent colours, such as Revolution Rainbow Tones, are nominally direct dyes and, unlike oxidative (permanent) dyes, there is no chemical reaction in their use. No mixing of separate components is required, they do not contain PPD and these colours will just defuse into the hair shaft.
There are very few restrictions on these dyes and they are generally considered to have a much lower risk of allergic reactions compared to permanents. Hence, the legally correct warnings on Rainbow Tones and simple usage instructions, when observed and followed, will ensure safe use of the products.
Temporary colours, such as Revolution Rainbow Paste, are pigments, which are the same as those used in colour cosmetics (e.g. lipsticks). They only coat the surface of the hair. As such they have the lowest risk of allergic reaction and do not require safety warnings.
3. Temporaries formulated as semi-permanents
Hair dyes such as Revolution Rainbow Shots, that are designed to wash out after 1-3 washes (Temporary) are actually formulated as semi-permanents but with a lower level of pigmentation, and direction to remain on the hair for a shorter period of time. Despite their more benign nature and very low risk of allergy, Rainbow Shots carry clear safety warnings on pack, to help ensure safe use.