Study examines plastic bag bans at consumer recycling sites

Results indicate a need for public education to reduce contamination of recycling streams, UB researchers say

BUFFALO, NY – Researchers at the University of Buffalo published a journal article quantifying the unintended consequences of New York State’s plastic bag waste reduction law and how to address them.

The aim of the study, which indicates that reducing society’s reliance on single-use plastics has clear environmental benefits, is to examine and help improve recycling efforts.

Described in Waste Management, “Impact of Plastic Bag Bans on Retail Return Polyethylene Film Recycling Contamination Rates and Speciation” details the composition of the retail return recycling streams before and after the implementation of the plastic bag ban in New York. York, which state lawmakers approved in 2019.

Before the ban, the most common post-consumer films returned for recycling were grocery and retail bags. However, return-to-retail recycling depots, often located at the entrances of grocery stores, also allow customers to drop off other polyethylene (PE) film materials. In fact, New York State’s bag ban requires stores to continue collecting these materials even though they can no longer distribute plastic bags.

John Atkinson, PhD, Scott and Coleen Stevens Chair in Sustainable Engineering at UB, as well as Jenna Meert and Austin Izzo, both graduate students in Environmental and Water Resources Engineering, collaborated with two grocery stores in western New York State to sort and quantify pre and post plastic bag bans returned materials.

With the plastic bag ban in effect, researchers found that contamination rates had increased 1.4 to 2.8 times. This increase adds to transportation costs and complicates the process of recovering these recycled materials.

“As more and more states implement bag bans, there may be implications for the recycling of post-consumer PE films. If the amount of material available for recycling decreases and becomes more contaminated, it may not remain economical to recycle those leftover PE films. Increasing PE capture rates and decreasing contamination after the bag ban requires training on return-to-retail programs and / or the implementation of innovative collection methods, ”says Atkinson, associate professor in the Department of Civil, Structural and Environmental Engineering.

Recycling streams from retail returns are contaminated due to several factors, and researchers have classified these contaminants. In addition to the obvious problematic items – such as food or stray liquids – non-PE plastics, vacuum storage bags, drink rings and other items contaminate PE films during the return to recycling process. detail.

“This is a vital study to examine the impact of plastic bag bans on the contamination rates of polyethylene film recycling,” said Amit Goyal, PhD, Distinguished SUNY Professor and Empire Innovation Professor in the Department of chemical and biological engineering.

The study is part of a multidisciplinary project led by Goyal and sponsored by New York’s Environmental Protection Fund and the New York Department of Environmental Conservation (NYDEC).

“Another part of this multidisciplinary project is focusing on the use of human behavioral sciences and awareness / education initiatives to help develop initiatives to tackle poor education and possibly reduce contamination,” said Goyal said.

On average, misinformation about what materials are allowed at retail recycling points – and which aren’t – accounted for 87% of total contamination. In other words, people drop wrong or unacceptable plastic items.

Helping people learn more about this particular recycling process should be part of any plastic bag policy, says Atkinson.

“This work emphasizes that future bag bans should include provisions that expand education around what is allowed in return-to-retail flows, as well as new signage and strategic placement of bins to maintain and even improve. , the quality and, potentially, the volume of these flows – even in the face of a ban on bags, ”he says.

Atkinson’s research does not conclude that bag bans are problematic – efforts to reduce the consumption of single-use plastics, especially hard-to-recycle materials like films, are essential. On the contrary, the results suggest that the increased contamination of return-to-retail films is a neglected consequence of these environmentally motivated efforts.

Bryce K. Locke