Makers of laundry detergent sheets tout their products’ eco-benefits, including their compact size; a reduction in detergent waste caused by drips, spills and overfilling; and their efficient, plastic-free packaging. The sheets contain polyvinyl alcohol (PVA), an ingredient that is also present in dish-detergent pods, which the U.S. Environmental Protection Agency has deemed safe for humans and the environment due to the fact that it biodegrades when exposed to certain microbes into water and carbon dioxide.

Unfortunately, PVA biodegradation conditions are not always present in municipal wastewater treatment plants. A 2021 study published in the International Journal of Environmental Research and Public Health estimates that approximately 75 percent of PVAs end up in the environment through sludge or water released from treatment plants. Because the majority of PVAs are made from fossil fuels, they add to global microplastic pollution.