Triethanolamine is a common ingredient in conventional beauty products. I've noticed it on the ingredient listing on a wide range of personal and skincare items....from soaps & shampoos to mascaras and hair conditioners.
It's used as a emulsifier, surfactant, masking and fragance ingredient.
Like all ethanolamines including diethanolamine (DEA) and monoethanolamine (MEA), triethanolamine is formed by a reaction of ethylene oxide and ammonia. Ehtylene oxide is a known carcinogen and ammonia is a known toxin.
Amines such as TEA can degrade and break down to carcinogenic nitrosamines in the presense of N-nitrosating agents like sodium nitrate, bronopol and brondiox. The FDA recommends keeping TEA and nitrosating agents apart and prohibits formulations using a concentration of greater than 5% of TEA in formulations.
TEA is often a blend of 85% TEA and 15% DEA. DEA, its close relative has been linked to certain cancers in laboratory tests on animals.
Some common abbreviations of ethanolamines in skincare and beauty product ingredient listings are:
TEA is can cause skin irritation if not washed off properly and respiratory responses in airborne products like hairspray.
TEA can result in irritation if not washed off properly. Imagine the long term effects of using a product with ethanolamines.
I would always err on the side of caution and steer away from it. After all, anything that is a by- product of reaction of two known toxins (ethylene oxide and ammonia) can't possibly be good!