This is Planet Money from NPR.

Back in the 1980s, here's how recycling worked.

You could recycle glass, paper, and metal.

But recycling plastic wasn't really a thing yet.

The cost of recycling plastic was really expensive, so nobody collected it.

This is COY Smith.

He ran a recycling business out in San Diego.

And even though it was too expensive, by the early 1990s, COY decided he was going to let

his customers recycle two types of plastic.

Milk jugs and soda bottles.

But then one day, his customers just out of nowhere started throwing in more than just

milk jugs and soda bottles.

They were throwing in peanut butter jars and strawberry containers and toothpaste tubes.

And COY Smith was like, wait, who told them they could throw all this plastic in the bin?

He starts looking at all the plastic.

He's flipping it over.

And then he sees something that he's never seen on the plastic before.

This little symbol.

The symbol starts showing up on the containers.

All this plastic, all of a sudden, is stamped with a little triangle of arrows.

You know the one.

The international recycling symbol.

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