June 27, 2018: Since this story was published, some options for recycling beyond the home bin have changed. Find up-to-date information about recycling

Greater Portland does a pretty good job of recycling. In 2015, more than 60 percent of everything residents and businesses threw away was recycled or composted. Diligent home recyclers check with a variety of resources when they aren’t sure what goes in the bin – asking their haulers, local governments and Metro what goes in the bin.

At the most basic level, it’s important to remember that the home collection system can handle only items that can be reliably sold for use in new products. And to sell those items for the materials in them, the recycling that's mixed together at home has to be sorted. Sophisticated machines handle a lot of the sorting, but they need to be able to work efficiently for the system to be effective.

Tubs go in, lids stay out. Because they are flat, lids end up getting sorted with paper, which makes the paper less valuable.

So how does that play out in the world of plastics? Let’s take a look at three items that do not belong in the home recycling bin – and why.

Plastic lids

Yogurt and salsa containers, and other similarly shaped plastic tubs, go in your home recycling bin. But the lids? Well, no.

The reason: Plastic lids can be recycled at some local facilities if you want to take them there. But when mixed with home recycling, lids end up being sorted incorrectly. Machines sort the flat lids with the paper, which lowers the quality of the recycled paper and makes it harder for recyclers to sell.

Plastic bags

Plastic bags catch in the machinery that sorts recycling, bringing the whole sort line to a halt.

Almost everybody uses plastic bags at some point, and they can be recycled if you drop them off at a grocery store or recycling facility that takes them. But they do not go in your home recycling bin.

The reason: When plastic bags are mixed with other recycling, they shred in the machines that sort out recycling. The film catches in the machinery and on the conveyors, bringing the whole sort line to a halt. Facility workers must then remove the plastic by hand to resume sorting. These stoppages slow down the recycling process – and can make recycling more expensive. And the offending shredded plastic film – the produce, grocery and freezer bags, and other types of cellophane and film – ends up in the garbage.

Plastic “clamshells”

Many newer plastics, like these deli containers, are not as valuable in the recycling market.

Those flip-open plastic containers that hold your lunchtime deli salads and sandwiches or cherry tomatoes are what recycling industry folks call “clamshells." Many have the triangular "chasing arrows" recycling symbol stamped on them. That means it’s recyclable, right? Well, not exactly. Some might be recyclable at a local facility, but none are recyclable at home.

The reason: These plastics are newer arrivals to the stream of plasticized consumer products, and the machinery at sorting facilities is not equipped to deal with them. But even if they were, many of these plastics aren't very valuable as recycled materials. So when you factor in the low value of these items with the cost of including them in home collection – the transporting, the sorting, the labor – it doesn’t add up. But some recycling centers take some of these plastics if you bring them in yourself, cutting some of the cost to collect them for recycling.

Bottom line on recycling plastic at home

Sort by shape, not by number. Know what goes in the bin and what stays out to ensure recycling remains cost-effective, and safe for workers. And remember, some of the stuff that can’t go in the home bin might be accepted at a local facility. Search Metro’s online database to find out.