Attack on Detergent Packets Ignores Decades of Evidence on Film Biodegradability

New online resources published by the American Cleaning Institute (ACI) provide science-based information about the technology behind water-soluble films, which are used to contain compact, convenient, pre-measured doses of detergent.

The information refutes criticisms questioning the materials' biodegradability launched by the interest group Plastic Oceans International, which relies upon a severely flawed research article and ignores decades of peer-reviewed studies on these widely used chemistries.

The films used in laundry and automatic dish detergent products are typically made of polyvinyl alcohol (PVA), also known as PVOH (since the OH is the alcohol group when expressed in a chemical formula). A great amount of research has gone into these films to ensure they are safe to use in the home, along with the ingredients they encapsulate, and that they meet rigorous standards to ensure they fully dissolve and biodegrade after use.

"These films are designed to dissolve completely in the washing machine and then flow down the drain with the wash water," said Kathleen Stanton, ACI Associate Vice President, Technical & International Affairs. "ACI's newest resource depicts the process of how detergent packets biodegrade, ultimately helping consumers understand the science behind their products."

Material suppliers and brand owners test to the highest global standards of biodegradability using independent third-party laboratories to verify their claims, ACI noted.

To counter misinformation about the biodegradability of PVOH, ACI worked with scientists and technical experts at several of its member companies to consolidate real-world research and data, now available on ACI's website.

The attacks made on PVOH biodegradability are based on a paper (Rolsky & Kelkar, Int. J. Environ. Res. Public Health 2021, 18(11), 6027) that ACI believes presents a flawed model and uses flawed data in that model. Any subject matter expert would see this paper as being designed not to test a hypothesis, but to arrive at a predetermined conclusion aligned with the opinions of the organizations funding the research.

According to an ACI analysis of the Rolsky/Kelkar research, their paper:

• Uses inaccurate market data that overestimates detergent packet sales by 3 times
• Bases estimates of U.S. wastewater treatment losses to the environment on data from India, which uses a completely different wastewater treatment system than that of the U.S.
• Uses only worst-case estimates for biodegradation data from grades of PVA that are not designed for use in detergent applications
• Does not distinguish the types or sources of PVA in wastewater (which may come from non-soluble grades used for other applications in other industries)
• Inaccurately depicts potential water-pollution concerns based on amount of PVA used in different geographical areas of the U.S.
• Incorrectly states that rapid biodegradation of PVA is ONLY possible within specific conditions, while citing data and literature that confirms the opposite ? that rapid biodegradation will occur with an unacclimated sludge
• Inaccurately states that the microorganisms required to degrade PVA are not found in wastewater treatment facilities, when the tests used by manufacturers that are required to prove biodegradation are conducted using inoculum taken from domestic wastewater facilities

"What we can say is that what is hypothesized in the paper wildly contradicts more than 30 years of published science and ignores the rigorous product design and test methods used by the cleaning products industry to confirm the ready biodegradability of detergent film polymers," said ACI's Kathleen Stanton.

"One need look no further than a recently published journal article to see this issue tackled head-on, with a thorough explanation of film design, test methods and conclusive evidence of biodegradability in the wastewater treatment environment."

That journal article is Byrne et al. "Biodegradability of Polyvinyl Alcohol Based Film Used for Liquid Detergent Capsules," Tenside Surf. Det. 58 2021 2.

The American Cleaning Institute® (ACI ? www.cleaninginstitute.org) is the Home of the U.S. Cleaning Products Industry® and represents the $60 billion U.S. cleaning product supply chain. ACI members include the manufacturers and formulators of soaps, detergents, and general cleaning products used in household, commercial, industrial and institutional settings; companies that supply ingredients and finished packaging for these products; and chemical distributors. ACI serves the growth and innovation of the U.S. cleaning products industry by advancing the health and quality of life of people and protecting our planet. ACI achieves this through a continuous commitment to sound science and being a credible voice for the cleaning products industry.