Why do transparent phone cases turn yellow after a while?


Note that this happens even if the phone rarely exposed to the sun light

In: Chemistry

Just like the sun’s UV rays damage our skin and turn it red, they make plastic polymers yellow through cell damage

The transparent phone cases are often made of polyurethane. When exposed to UV light, polyurethane can degrade and become oxidized, turning into yellow-ish compounds called quinones.

You’re washing your hands after you pee, right? Right?!