Repellency and Environmental Concerns | RTI Innovation Advisors
A worldwide consumer goods client had a straightforward goal. They wanted to understand water and oil repellent coating technologies that are safe for people and the environment.
To meet their goal our client was considering transitioning their products from long-chain to shorter-chain perfluorinated chemicals (PFCs) and asked for our independent review of the science.
Perfluorinated chemicals: backgrounder
PFCs are the chemicals that make many of our everyday products water-, stain- or grease-resistant. PFCs are part of the broader class of halogenated materials, which contain fluorine, chlorine, bromine, or iodine.
In many consumer products, oil repellency is a desired trait; consumers want stain-resistant fabric to make a salad dressing spill easy to clean and non-stick cookware that allows an egg to slide off the surface. To achieve oil repellency the surface energy of the underlying layer must be lower than the surface energy (tension) of the liquid (oil). Oil has such a low surface tension that very few coatings or materials have lower surface energy. Halogenated materials and particularly PFC-based coatings are one of the few durable and cost-effective options. While PFC coatings are effective, they come with environmental, health, and safety concerns. (1)
Long-chain and short-chain PFCs
PFCs are described by the number of carbons in the chain: long-chain PFCs have at least eight carbons (called C8) while shorter-chain PFCs generally have fewer than six carbon atoms (called C6). Long-chain PFCs have been under pressure from regulators and environmental groups for some time; this is due to their persistence in the environment, significant human exposure, known animal toxicity, and insufficient understanding of their risks to human health. (2) These chemicals are so persistent that they are being found in animals in remote locations and are remaining in the environment. One compound, perfluorooctanoic acid (PFOA), has been found in wild animals including polar bears, arctic foxes, ringed seals, mink, birds, and fish collected in the Arctic. (3) The prevailing industry belief is that using shorter-chain PFCs (C6 or shorter) mitigates the environmental and human health effects.
In our home state of North Carolina, the issue of PFCs has been at the forefront recently with the discovery of fluorinated compounds in both the raw water intake and the final drinking water of some municipalities.(4) One source of contamination is GenX, an unregulated chemical discharged into the Cape Fear River from a plant owned by Chemours and DuPont. GenX, a tradename for the C6 compound perfluoro-2-propoxypropanoic acid, had been touted by DuPont as a more sustainable process that avoids the use of the C8 compound, PFOA, but there is a lack of scientific data on the long‐term health effects on humans. However, animals that were exposed to different levels of GenX show harmful effects to the liver and blood, and cancers (liver, pancreatic, testicular, and uterine); researchers in North Carolina have only begun the first human study.
In addition, a research team from Duke University found other fluorinated compounds ranging from C4-C9 in Jordan Lake, a local drinking water source, as well as in the drinking water in several of the local cities, including Cary, Chapel Hill and Durham. Although individually the concentration of each chemical was below the EPA regulatory level of 70ng/L, the combined level in some drinking water samples approached 200 ng/L. (5)
Objective advice leads to updated innovation plan
Our client came into the project with an admirable goal: make the chemistry used in its products safer for humans and the environment. Our client thought using shorter-chain PFCs would be the best option but wanted to be sure before investing millions in R&D and product changes. They asked us to build a landscape of repellent technology options, help educate them on how repellency is achieved, and provide an objective, independent review of the science.
Through a combination of literature review and interviews with subject matter experts, we found the current research to be inconclusive. There is not enough evidence to be certain that shorter-chain PFCs are safer, and they may be even more dangerous than their long-chain counterparts. Short-chain PFCs have recently been found in higher concentration than long-chain PFCs both in the environment and inside our bodies. (6,7,8,9,10) We also learned that several large household brands were removing PFCs from their supply chains entirely and that new solutions were emerging as the market for textile repellency coatings began to respond to this need.
Because of our work, our client changed its innovation plan. Rather than pushing forward with the shorter-chain PFCs, they’re shifting focus to other solutions identified by our team that will allow them to remove PFCs completely. This was an impactful moment for their team, and for us as researchers. More to come in our next post on what this project meant to us!
About the Authors
Jamie Pero Parker, Ph.D. focuses on open innovation and technology commercialization and has experience in green, bio-analytical, and biophysical chemistry. She leads technology and business intelligence scouting initiatives, strategic technology and market analysis, commercialization assessments, partnership identification and development, and technology scouting training. Jamie also works with clients to create, augment, and manage new product ideas from various technology platforms. She is most interested in using open innovation to create more sustainable technologies and products and strives to incorporate a green element into her work. Jamie has a Ph.D. in Analytical Chemistry from the University of North Carolina at Chapel Hill and a B.S in Chemistry of the University of Utah.
Allison Sykes, Ph.D. assesses technologies for commercial potential, performs market research, and creates commercialization strategies for high-potential technologies, and has experience in technology areas including antimicrobials/pesticides, controlled-release technologies, new and emerging coatings, and materials. Her background includes organometallic chemistry from her work as a research associate while completing her Ph.D. in Inorganic Chemistry and water disinfection from her postdoctoral associate position, both from the University of North Carolina-Chapel Hill. She has a B.S. in Chemistry from Washington and Lee University.