Why does leaving plastic out in the sun get rid of stains that refuse to wash out?

Question

I saw someone asking how to remove a yellow turmeric stain from a blender cup & lots of folks recommended leaving it out in the sun to break down the pigment. Why does this work when water & scrubbing doesn’t?

In: 39

Answer 1

I learned this in organic chemistry once lol. Something about the radiation disrupting electron resonance. Eight years later I can’t explain it for *any* age group!