Thursday, April 24, 2014
As I mentioned in my last post, most recycled plastic just ends up getting downcycled at best, dumped/landfilled at worst.
Simple, really: pathogens & contamination.
When you recycle a glass bottle, or aluminum can, or steel, that material is remelted at extreme temperatures. Bacteria and pathogens burn off, and impurities can be skimmed away. Leaving you back with nice new glass, aluminum, or steel.
You can’t do that with plastic. Each time you remelt plastic, the long, flexible polymer molecules break down, interconnect, and stiffen. The plastic becomes irreversibly weaker. And plastics melt at temperatures so low that it’s very hard to ensure all pathogens are destroyed.
In addition, plastics often contain one or more additives (antimicrobials, antioxidants, blowing agents, fillers, flame retardants, fragrances, heat stabilizers, impact modifiers, light stabilizers, pigments, plasticizers, reinforcements, etc.). These often don’t play nicely together and must be carefully sorted and categorized to avoid contamination.
A typical materials recovery facility, source: Michal Manas
Moreover, accidentally mixing one kind of plastic in with another can ruin a batch. #3 PVC plastic looks & acts a lot like #1 PET. But one #3 bottle can ruin 10,000 #1 bottles’ worth of plastic -- leaving horrid black smears through all of that melted #1 PET, releasing toxins too.
This is why the FDA regulates plastic recyclers. A recycling company cannot turn a recycled soda bottle or milk jug into another food-grade container without a “Letter of No Objection” (LNO) from the FDA.
The most robust and easiest-to-recycle plastic is #1, PET. In 2012, 27 recycling companies in the US processed recycled #1 PET plastic. Barely half had received LNOs (p. 6 of trade-industry report).
And getting high-quality plastic is always difficult. One company in Richmond, Indiana* recently reported that it sometimes can use as little as 42% of a bale of #1 PET plastic it receives.
The outlook is even more dire for all other plastics. #2 plastic, HDPE (the stuff in milk jugs), is the next “easiest” to recycle. Precisely one company in the US has received an LNO to reproduce food-quality #2 plastic. More than 99% of the #2 plastic milk jugs & other food containers that we Americans recycle are still at best being turned into lower-grade material (p. 12 of report for 2012).
Every year or so the plastic industry touts the “next new thing” that will revolutionize plastic recycling. In 2009, Coke invested tens of millions into a plant in South Carolina that was going to be a flagship bottle-to-bottle recycler. Two years later the plant reportedly suspended operations and laid off 50 staff. Bottle production had changed and the recycling technology couldn’t cope with the change.
Maybe one day true closed-loop plastic recycling will be a reality. But 42 years after the first recycling plant opened, we’re not all that far down the road yet.
* This article originally said Richmond, Virginia -- an astute reader pointed out my mistake, thanks!
Visiting a Maine beach in March 2010, Harold Johnson was shocked by the ocean-borne debris left by recent storms. He grabbed a garbage bag and a camera, and hasn’t looked back.
Since then he has spent most of his free time studying marine pollution, coastal ecosystems, and the mysteries and science of ocean and shore.
Copyeditor and writer by trade, historian and archaeologist at heart, Johnson’s philosophy is simple: Dig below the surface, travel the currents, make the connections, learn. Then share what you learn. He lives in Saco with his wife and young daughter. Follow on Twitter @FlotsamDiaries.