Polysorbate 80 is an irritant? I dont think so. In spite of your Internet research, I have over 40 years of personal hands-on experience with it. It is not an irritant, in fact, it is quite the opposite. It is my “go to” to prevent scalp irritation, when a client suddenly develops a sensitivity, or rash, to their current hair color formulation, and has never failed me in that result.