Why 20 Million Mattresses Will Outlive Your Great-Grandchildren

And it’s actually….okay? 

This week we’re getting into: 

• The Landfill Time Capsule: Why mattresses do not rot, how modern dumps act like mummification chambers, and why that is actually better for the climate than food waste.
• The Bioplastic Dilemma: When paying extra for compostable packaging actually helps the planet, and when it is just expensive trash.
• Actionable Sustainability: Why keeping your banana peel out of the trash matters more than your old mattress, plus practical steps to dispose of both responsibly.

Every year, Americans throw out up to 20 million mattresses and box springs, according to the Mattress Recycling Council. Most of them end up in a landfill, where they'll sit, more or less intact, long after anyone who slept on them is gone.

I think most people picture a landfill as a giant, smelly compost pile where you throw something in, wait long enough, and nature handles the rest. Turns out that's almost exactly backwards.

A landfill is actually a time capsule.

In the 1970s, an archaeologist named William Rathje started digging into landfills the way you'd dig up an ancient city. His team, the Garbage Project, kept pulling up newspapers from decades earlier that were still readable. In one dig they found a bowl of guacamole that, years later, was still recognizably guacamole. Modern landfills are lined on the bottom, capped on top, and compacted tight to keep trash from leaking into groundwater. That also keeps out the two things decomposition needs most: oxygen and moisture. The whole situation is actually closer to mummification than rotting.

Now put a mattress in there. A conventional one is mostly:

• Polyurethane foam, a petroleum-based plastic that doesn't biodegrade in any meaningful sense. It might crumble into smaller pieces over decades. It doesn't go away.
• Steel springs, which rust very slowly in a dry, airless pile.
• Synthetic fabrics, adhesives, and flame-retardant layers, more plastic and more chemistry.

Mattresses are famously annoying to bury. Massachusetts banned them from the trash in 2022, and its environmental agency said discarded mattresses are "expensive to transport, hard to compact, take up lots of landfill space, and can damage incinerator processing equipment." They spring back. Landfill operators hate them.

So yes: your mattress is going to outlive your great-grandchildren. And...

The mattress isn't the climate villain. Your banana peel is.

Something that just sits there in a landfill is a waste of space and resources. I don't want to minimize that, there's only so much land for landfills, right? But it isn't making much greenhouse gas. The climate problem is the stuff that does break down, like food scraps, yard waste, paper. Buried without oxygen, they rot the anaerobic way, and the main byproduct is methane, which traps more than 80 times as much heat as CO2 over its first 20 years in the atmosphere.

Landfills are the third-largest source of human-caused methane in the U.S., according to the EPA. The EPA also estimates that food waste causes about 58% of the methane that escapes from landfills, even though food is only about a quarter of what we bury. Why so much? Food breaks down fast, often before a landfill's gas-capture system is even installed over that section. Read that again: the faster something decomposes in a landfill, the more likely its methane gets away.

Which brings me to bioplastics.

Bioplastics: the expensive ones that act like regular plastic, and the ones that act like food

"Bioplastic" covers a lot of different materials, but two show up most in your cart:

• PLA (polylactic acid, usually made from corn) is the clear "compostable" cup and the stiff "plant-based" clamshell. It breaks down in an industrial compost facility, which keeps it hot, wet, and well-oxygenated for weeks. In a landfill it mostly just sits there, a lot like regular plastic.
• PHA (made by microbes) really does break down in low-oxygen conditions. Lab studies have found its methane output is similar to food waste. That's great in an anaerobic digester built to capture methane for energy. In a landfill, it can add to the methane problem.

So bioplastic is never automatically good or bad. It depends entirely on where it ends up.

When bioplastic is worth the money

You have curbside compost or a drop-off that specifically accepts compostable packaging. Not just food scraps. Check, because plenty of programs take your banana peels and reject the "compostable" fork.

It's carrying food to the compost. A certified compostable bin liner that gets your food scraps into compost instead of the landfill is doing real work. This is the best use case, because keeping food out of the landfill is the whole ballgame.

It's a closed loop. Stadiums, cafeterias, and events where everything goes to the same composting facility.

It's certified. Look for the BPI logo (U.S.) or TÜV "OK compost." Those mean an actual standard was met.

When it's probably not worth the premium

You're paying extra just for "compostable" and it's going in the trash.** In a landfill, PLA acts a lot like regular plastic and PHA can act a lot like food, so the compostable part doesn't get to do its job. (Where the plastic comes from is a different story. More on that below.)

It's going in the recycling bin. PLA looks like the clear PET plastic in water bottles but melts differently, so recyclers treat it as a contaminant. "Compostable" packaging in the recycling bin makes recycling worse.

It says "biodegradable" with no certification. That word has no required timeline or setting. Everything is biodegradable if you wait long enough and are vague enough.

It's "oxo-degradable." Never heard of this? You don’t need to. The EU banned it in 2021. Skip it.

Here's why we still recommend them

Our trash bag guide recommends compostable trash bags, and I'm sticking with that, even knowing most of them end up in a landfill.

To be honest about it: the emissions difference between plant-based and petroleum-based plastic is smaller than you'd hope. Some studies find plant-based plastic comes out a bit lower. Others find it's about even once you count the farmland cleared to grow the crops. Growing corn isn't free.

But for me, this was never only about the emissions math. Every petroleum-based bag is a tiny vote for drilling, fracking, and an industry that has spent decades making itself impossible to quit. Anything that moves money away from fossil fuels is a win in my book, even when it's imperfect and even when the numbers are close. Imperfect alternatives are how better ones get built.

A couple of things so you're buying with your eyes open:

• Read the label. A lot of compostable bags are blended with PBAT, a compostable plastic that's still made from petroleum. Look for bags that tell you how much of them is plant-based.
• If you have compost, start there. Lining your compost bin is where these bags do the most good.
• Recycled plastic bags are a good option too. They keep new plastic from being made at all, and they're usually cheaper.

So what do you do with your mattress?

1. Make it last. The most sustainable mattress is the one you don't replace. A mattress protector and regular rotation extend its life more than you'd think.
2. Check if your state has a program. California, Connecticut, Rhode Island, and Oregon run "Bye Bye Mattress" recycling, funded by a small fee you already paid when you bought your mattress, so use it. Massachusetts bans mattresses from the trash entirely. The Mattress Recycling Council says up to 75–80% of a mattress (steel, foam, wood, fiber) can be recovered.
3. Ask where the haul-away goes. If a retailer offers to take your old one, ask whether it's recycled or just dumped somewhere.
4. And while you're at it, get your food out of the trash. If you only change one thing after reading this, make it composting. That's where the landfill's real climate damage comes from.
5. Make sure your new mattress is Finch-approved. 

Your mattress will outlive your great-grandchildren. Your banana peel shouldn't get the chance to.