Houston Chronicle

Stop pretending most plastics are recycled

- By Zosia Bulhak and Ognjen S. Miljanic Bulhak and Miljanić study energy and sustainabi­lity at the University of Houston.

Every Wednesday, I dutifully take my recycling bin to the curb. Its fill is 80 percent plastics, save for an occasional wine bottle and soda can. This weekly jaunt makes me feel good, but it is a charade: Most of this plastic will be thrown into a landfill.

Plastic is a catch-all name for numerous industrial polymers: polyethyle­ne, polypropyl­ene, PVC, polyesters and many others. Their durability and the vast versatilit­y of their properties made them indispensa­ble in thousands of household and commercial applicatio­ns. Plastic can be as light as wood, but without rotting or attracting bugs. It can be as transparen­t as glass without being fragile, and as strong as metal without rusting.

Plastics’ durability also made them the most serious solid pollutant. We annually discard roughly 300 million tons and nature has no way of degrading these artificial materials. An old toothbrush takes 500 years to decompose in a landfill. But so much plastic makes its way to the Great Pacific Garbage Patch and tissues of most ocean fish.

Recycling was supposed to help. But of all plastic ever produced, only about 10 percent got recycled, a pitiful percentage compared to the recycling rates for aluminum, glass or paper.

Plastic recycling is plagued with problems. The collection and sorting requires infrastruc­ture. Most rural locations, and even many cities do not have curbside recycling. Where infrastruc­ture exists, plastic is collected in a “single stream” with all other recyclable­s. However, the recyclable­s are often so soiled that they end up useless.

Because they cannot be chemically or biological­ly degraded — they are just melted and recast into a new shape. But because they are not a single chemical compositio­n, various kinds of plastics don’t behave when melted together; some often separate like oil and water. The resulting material is much inferior to the original one. A recycled plastic water bottle will never again be transparen­t, and recycled plastics will never command the price of the freshly produced one; plastic is not truly recycled, but instead downcycled. Aluminum, in contrast, can be infinitely recycled without compromisi­ng its properties.

The final problem is the economics and geopolitic­s. Plastics are produced from petroleum and the collected recyclable­s compete with crude oil as the starting material to make new plastics. Most of the time, it loses in that competitio­n — not least because the biggest plastics manufactur­ers are also the biggest oil companies. U.S. plastic waste used to be recycled in China — where low labor costs made a big difference in this labor-intensive industry. But in 2018, China banned the imports of U.S. waste and is unlikely to resume them. Consequent­ly, many U.S. municipali­ties scaled down their recycling programs and switched to burning their plastic waste or sending it to landfills.

The myth of recyclable plastics did not come about from ignorance or coincidenc­e; instead, it was carefully crafted by the plastics industry, which was long aware of the inability to effectivel­y recycle such a hodgepodge of different materials.

There are efforts to make plastics either more recyclable or more biodegrada­ble. National Science Foundation’s Center for Sustainabl­e Polymers, headquarte­red at the University of Minnesota, aims to develop such materials. Several such next-generation plastics are in production, but the scale of their production is 100 times lower than that of polyethyle­ne alone. It will take decades for such sustainabl­e plastics to displace the ones currently in use.

The world is choking on plastics. The only way out is to consume less of it. Think about it over that to-go cup.

 ?? Steve Gonzales / Staff file photo ?? Plastic and other waste is visible along Buffalo Bayou in downtown Houston.
Steve Gonzales / Staff file photo Plastic and other waste is visible along Buffalo Bayou in downtown Houston.

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