I think with hair styling gels and waxes and putty whatever, doesnt cause hair loss. You can look at companies that pride themselfs on the stuff they put in like blumann or chapter or something like that if you think your brand is bad.
I think with hair products its important to give your hair a break from time to time but none willl cause perminate damage.
Hair colour not sure on this, bleach will screw your hair not sure about the normal hair dies though havent had to use any yet
