Butylated hydroxyanisole (not to be confused with the anti-ageing BHAs and AHAs) is used as a preservative and anti-oxidant in personal care products.
BHT’s are a toluene-based product also used as preservatives. Banned for use in cosmetics in the EU as a known endocrine disrupter, it can be reasonably anticipated to be a human carcinogen and a known reproductive and developmental toxin.
It is known to be most toxic to pregnant women and infants.