Impact of plastic bag bans on retail return polyethylene film recycling contamination rates and speciation

•First study to report role of “bag bans” on retail return polyethylene contamination.•1.4 – 2.8x increase in post-“bag ban” contamination from concentration effect.•43-category contamination speciation increases understanding of the material stream. Plastic films are abundant, but seldom recycled in the United States (US). It is both economically and operationally challenging to recycle plastic films because their light weight makes accumulating material difficult. Additionally, films are not allowed in most curbside recycling programs in the US because they tangle around equipment used at material recovery facilities (MRFs) and effect a MRFs’ ability to effectively sort other materials. As a result, the only recycling pathway for post-consumer plastic films in the US is retail return collection programs. Currently, only the most abundant type of post-consumer plastic film, polyethylene (PE), is accepted by these programs in the US. Although PE films come in many forms, grocery bags are the most well-known, and therefore most abundant, film in the retail return recycling stream. The New York State (NYS) Plastic Bag Waste Reduction Law prohibits the distribution of single use plastic bags. This work explored how ending the distribution of grocery bags impacted retail return recycling programs for PE films in Western New York. We show that a loss of the most recognizable and abundant PE film results in a 1.4 – 2.8x increase in contamination rates, devaluing films that are still collected. As a result, increased contamination rates may threaten the viability of this recycling pathway. The study also provides a complete speciation of this recycling stream with a novel level of detail, as existing research on this recycling pathway is limited.