I have super acid hands. I melt newspapers and magazines in under 3 minutes.
I have PBT keycaps from 1987 that still look perfect and I typed the hell out of them, dropped them on floor a few times each year, gamed on them some, etc. etc. They are all in perfect shape.
None of the keycaps were white though. They are all Beige. But I donno if that matters. I have friends with PBT keycaps from 1985 that are white or offwhite and they still look perfect.