That is, until I'm done, and I have to decide what to do with my cup.

Can I recycle it?

Is that a trick question?

Yeah, this is a great question.

I just figure you can recycle anything that's cardboard-esque.

That's not right!

I can't recycle this?

Knowing what you can and can't recycle isn't easy.

The rules depend on where you live.

And there are hundreds of products and materials where the rules aren't always clear.

Pizza boxes?

I hear that that's not recyclable.

I don't know if that's like a legend, an urban legend or something.

Paper towels?

My roommate and I actually have this discussion where I'm like, I'll throw paper towels in there.

And she's like, "I don't think you can recycle that" and she'll pick them out.

Like, I don't know, it's paper.

Bubble wrap mailers.

I don't know, this is so hard!

The confusion means that things that are actually garbage still end up in the recycling stream.

About 25% of what Americans try to recycle can't actually be recycled.

Waste management experts say what's going on here is something called "aspirational recycling".

When people are unsure if an item can be recycled, they recycle it, because it feels like the right thing to do.

And while our intentions are good, this behavior isn't harmless.

Even small amounts of contamination can turn entire hauls of otherwise recyclable materials into trash.

And the problem has been growing.

The rate of recycling contamination more than doubled in the last decade.

So, why is this happening?

Well, it is at least in part due to a major shift in how Americans recycled.

Beginning in the 1990s and 2000s, municipalities implemented "single stream" recycling programs.

Paper, metal, plastic, and glass no longer needed to be sorted.

They could all live in one bin.

Communities quickly adopted the practice and, by 2014, 80% of all curbside recycling programs in the US were single stream.

The problem is, there's evidence that when we put all our recycling into one bin, we're more likely to throw trash in there along with it.

Take two neighboring counties in Florida, for example:

Palm Beach County, where residents must pre-sort their recyclables, had a contamination rate of only 9%,

while Broward County's single-stream program had a contamination rate of 30%.

Single-stream recycling takes the responsibility to sort off of the individual and shifts it to Materials Recovery Facilities, or MRFs, where trash gets sorted out from recycling by machines.

But also by workers, who often have to remove waste by hand.

Pizza boxes contaminated with grease, electronics that aren't processed at standard recycling facilities.

Even the likes of Christmas lights, animal carcasses, and bowling balls.

In Portland, workers remove thousands of dirty diapers every month.

In a perfect world, everyone would just know how to recycle correctly.

But short of that, there's something we can all start doing differently right now.

Unless you are absolutely sure, don't recycle it.

In fact, recycling education campaigns encourage the opposite: When in doubt, the best option may be to throw it out.

Most people want to do the right thing, and sometimes the way to be a good recycler is to throw stuff in the trash.

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