I’ve decided to do my seminar this semester on the chemistry of hair care. You know, I’m going to talk about all that junk on the back of shampoo bottles that you never really cared to know about– DMDM hydantoin, cocamidopropyl betaine, PPG-9, etc. I’m aiming for practicality here.
Many shampoo ingredients have some fascinating properties. DMDM hydantoin, for example, is a biocide and preservative that works by releasing formaldehyde. “Formaldehyde? In my freakin’ shampoo?” you may ask? To which I would reply, “only in dilute quantities my friend, and it reacts right away outside your body.” W.B. Neely discovered way back in the decade of love that dilute formaldehyde interferes with the growth and division of Aerobacter bacteria by interrupting the biosynthesis of methionine.