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Sustainability | Ecotrope

Recycling 101: The Numbers Game

Why doesn't the recycling number on the bottom of this yogurt tub match the number on the lid? And can I recycle both?

Why doesn't the recycling number on the bottom of this yogurt tub match the number on the lid? And can I recycle both?

This one comes from my own personal arsenal of pesky recycling questions: What’s up with the numbers inside those raised recycling triangles on plastic containers? Are they trying to tell me something? Because apparently I haven’t been listening.

Sometimes, I’ll check the number in vain before ditching a plastic cup and then wonder for a few moments, helplessly, whether I just committed an environmental sin.

I asked Metro Recycling Specialist Patrick Morgan: How am I supposed to use this cryptic number system?

His answer? Don’t bother. At least when it comes to curbside recycling in Portland.

“It really isn’t that helpful anymore,” he said. “I’ve seen port-a-potties that have the number 5 on them.”

What about this plastic cup? It has a recycling triangle on it ... and the number 5.

What about this plastic cup? It has a recycling triangle on it … and the number 5.

Once upon a time, Portland tried using a number system to determine which plastics people should put in the curbside bin. People remember back to those days, Morgan said, but they shouldn’t.

“It’s really not that system anymore,” he said. “The whole plastic industry morphs so much. There are more and more types of plastic, and more additives. So, we’ve moved away from using the numbers.”

One of the big problems with the numbers is they don’t tell you how a plastic product was manufactured, said Morgan. And that factor makes a huge difference in the recycling process.

“You can have two different things made out of number 2 plastic, but one might have been formed one way and one the other way,” he said. “The value of something that’s been blow-molded is going to be much greater than injection molded. The injection molding doesn’t result in a high-value container or material. It compromises the integrity of the plastic itself.”

For example, he said, tubs, bottles and jars are blow molded in a process similar to how glass is blown. Those are the ones you can put in your curbside bin in the Portland metro area.

But the plastic clamshell or hinged containers often used to package berries or take-out orders is injection-molded. Those cannot be recycled curbside. (Here’s Metro’s handy guide to “yes” and “no” plastics)

“They can still be received at recycling depots because separating them there lowers the cost of sorting, but they don’t have enough value to make it worthwhile to do it curbside,” said Morgan.

There are also additives in some plastics that can lower the end value when recycled.

But if you are dying to recycle a plastic item, he says, you should check around and see if a recycling center such as Far West Fibers, Recology or Total Reclaim – will accept it. Some even take styrofoam!

There are many guides that will tell you precisely what each number means, if you really want to know (I like this one from National Geographic). It’s a “resin identification code” that indicates which type of plastic resin has been used to make the product. Apparently, some resins and their production processes have been linked to health and environmental concerns, so maybe there is a reason to play the numbers game after all …

Recycling Recycling 101

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