What do the signs and numbers on plastics mean?

Question

So I always see these signs and numbers on plastic containers, what do they mean?

[Here’s a photo of those numbers/signs from something I just threw away.](https://imgur.com/K1krehk)

In: Chemistry

Answer 1

The triangle with a number inside is **not** a recycling symbol, it’s a [resin identification code](https://en.wikipedia.org/wiki/Resin_identification_code) (RIC). In particular, the code 5 shown in your picture “signifies polypropylene (PP) (auto parts, industrial fibres, food containers, etc.)” and these can’t usually be recycled.