Compostable cups, forks, takeout containers, bags, and packaging are increasingly easy to find. On the surface, they seem like an obvious improvement over conventional single-use plastic: use something once, toss it in the compost, and let nature take care of the rest.

But the word compostable often comes with a lot of fine print. Many compostable plastics require specific heat, moisture, and microbial conditions to break down. Your backyard pile may not provide them, and even your local commercial composting facility may not accept the product in the first place

So when a package says “compostable,” what does that actually mean? And, perhaps more importantly, where should it go when you’re finished with it?