‘Forever chemical’ replacements are on the way thanks to sustainable coating research and collaboration.
By George Osterhout, Surface Solutions Group
Fluoropolymers are getting a bad name.
For more than a decade, perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) used to manufacture polytetrafluoroethylene (PTFE) coatings for the medical device industry have been highly scrutinized by regulatory agencies including the EPA and the EU Medical Device Regulation (MDR).
In 2010, the EPA recommended the elimination of PFOA in all PTFE coatings by 2015, including those used for medical devices. PTFE coatings are used for guidewires, mandrels, hypotubes, coil wires and needles. Since then, PTFE manufacturing companies have turned to short-chain perfluoroalkyl and polyfluoroalkyl substances (PFAS) as an alternative, which seemed like an effective substitute — until it wasn’t.
There are thousands of chemicals that fall under the PFAS chemical bracket. PFAS are labeled as “forever chemicals” because they are widely used and break down very slowly in both the body and the environment. These alternative PFAS chemicals are under scrutiny with approaching deadlines to be handed down by EU regulators for elimination of their use as well.
Promisingly, research and development efforts have eliminated not only PFOA but also PFOS. Through similar research and best available technology, there will be replacements for the PFAS that are used in manufacturing PTFEs, making solid headway toward more sustainable functional PTFE coatings.
The long history of PTFE
PTFE was discovered by accident in 1938, the by-product of another project. That was DuPont’s very first Teflon, which helped to revolutionize manufacturing. The molecule PTFE is inert and is not water soluble. At 0.05µ to 0.10µ, it has an extremely low coefficient of friction, making it ideal for heightening the performance of many products, from cookware to containers, pipes, automotive parts, and machinery.
For the medical device industry, PTFE has reduced the dynamic efforts required for maneuvering various guidewires through small vessels and arteries in the body to perform life-saving procedures. But it is the chemicals used to make PTFE that are now deemed undesirable.
The problem with completely eliminating PTFE in the coating is that medical devices, and so many other products, cannot effectively function to the standards we have come to expect. Fluoropolymers, or PTFEs, are used in millions of products we use every day. Without them, or a sustainable alternative, medical device efficacy and patient outcomes could be set back years. Hence, it is quite a wake-up call for the designers and engineers who must remake the devices to be compliant.
Compliance-led change in medical device product development
Because of the recent concerns about PFAS being forever chemicals and the EU looking to eliminate use in the near future, there is the potential for the EPA restrictions to follow the EU.
This has created a significant change for medical device companies under pressure to develop or source new sustainable replacement coatings that perform as well as the restricted counterparts. The device manufacturers are seeking more sustainable PTFE coatings, along with alternatives to PTFE.
This is quite a role reversal for medical device designers and engineers who traditionally drove the use of PTFE coatings. Instead, they find themselves in reactive mode, and are experiencing increased involvement of regulatory departments and validation teams in the replacement of legacy PTFE coatings. The designers and engineers are searching for coatings that meet or exceed current regulatory requirements and those that they anticipate will be handed down in the future.
The rise of sustainable coatings
As a result of the changing regulations, major players in the market are significantly shifting their product strategies.
3M has chosen to completely cease making PFAS by 2025, while PPG has stopped making coatings for medical device use. Chemours has stepped up to the challenge and has committed to eliminate at least 99% of all PFAS used in the processing of PTFE by 2030.
Two other coatings manufacturers are also pushing forward, using established scientific data to reformulate existing coatings and create new ones to reduce the use of restricted chemicals while meeting product performance standards. For them, it is imperative that they relentlessly pursue viable solutions and attempt to fill the all-too-critical supply chain gaps left by others.
These companies have developed water-based, low friction, biocompatible medical device coatings that are free from any PFOS, PFOA, solvent, and hex chrome compounds. They’re also REACH and RoHS compliant.
One company, Cavero Coatings, offers a coating that contains as much as 60% binders and pigments, with the balance being PTFE.
Another company has joined forces with functional coating technology company Surface Solutions Group (SSG) to create SSG’s GlideMed coating, which contains no PTFE. Our R&D teams have worked together to test and validate this coating to provide the needed, reliable data for design engineers. Independent test results indicate that its lubricity, durability, and adhesion properties are proving it to be a good, sustainable alternative to traditional PTFE coatings.
A promising future for medical device coatings
Throughout the medical device industry there are varying degrees of success as chemists and engineers collaborate and navigate the possibilities.
Still, there is some rough terrain ahead for everyone who uses PTFE. They will need to adapt, as they have through the years, to comply with ever-changing regulations.
Fortunately, with continued research and innovation, the future holds much promise for creating more sustainable, compliant coating solutions.
George Osterhout is the president at Surface Solutions Group (SSG) and a career veteran of the coating industry. A respected leader in the development and application of functional medical device coating technologies, SSG offers 13 proven medical coating categories, giving its medical device partners the widest range of coatings available through a single supplier.
The opinions expressed in this blog post are the author’s only and do not necessarily reflect those of Medical Design & Outsourcing or its employees.