What you need to know about bio-based plastics

We've all heard a lot about the dark side of plastics. Two common criticisms: They're made from petroleum (a non-renewable resource that's in short supply), and they hang around in landfills for centuries.  

You can now buy items such as disposable plates, cutlery, and garbage bags made from corn, potatoes, and other agricultural products instead of oil. These renewable alternatives to petroleum are also designed to break down much more quickly than their typical plastic counterparts.

While there's no denying these are admirable benefits, it's important to take a look at the drawbacks as well.

For example, there are legitimate concerns about displacing food crops to make plastics. The real hope is that eventually most of the products will be made from agricultural waste rather than food crops, says Darby Hoover at the Natural Resources Defense Council.

It's also a good idea to become acquainted with the circumstances in which they'll biodegrade (break down into smaller components). 

Here's what you need to know about buying and disposing of the latest generation of plastics.  

Buying

• Look for products that are entirely bio-based, or are labeled "biodegradable" and "compostable."
• Choose products made from agricultural waste materials such as bagasse (the waste portion of sugar cane crop) when possible, rather than polyactic acid (PLA), a more common option made from corn. 

Disposing

• While bio-plastics do biodegrade, it's unlikely that will happen in a landfill or even your household compost facility. That's because the disposable plates, cutlery, and containers need to be fairly stable so you can use them. In most cases, they need to be sent to commercial composting facilities to biodegrade, says Hoover. Call your local waste management authority to find out if you live in one of the few communities with this option.  
• If not, do not mix bioplastics in with regular plastics for recycling. If you don't have access to a commercial compost facility you should dispose of them with your garbage, says Hoover. Some products do say they can be composted at home. The only way to know for sure if a particular product will break down in your composting system is by trial and error. 

The bottom line? There are definite benefits to bioplastics if you have the means to compost them, especially if they're made from agricultural waste products. You can still make a difference by buying them even if you can't compost properly because you're voting with your dollars for products that aren't made from petroleum. It's up to you to decide whether to cast that vote.