Bisphenol A (BPA) is a chemical used to make polycarbonate plastic found in items like Nalgene water bottles and epoxies.

“bisphenol a or BPA is the one that most people are familiar with um ironically um the presence of BPA at least uh being used actively uh has been reduced quite a bit over the past 15 years but just understand that there's a whole family of these uh bisphenols and typically we substitute one for the other um but what are they right they're chemicals that are used to make polycarbonate plastic polycarbonate plastic is the hard plastics we have in our world so if you think about all the places where you use plastic and it's hard uh I think of kind of the Nalgene type water bottles epoxies resins things like that that's where you're going to have historically found a lot of BPA”