To Keep Pace With Emerging PFAS Regulations, Labs Must Modernize Their Analytical Science

Per- and polyfluoroalkyl substances (PFAS), also known as forever chemicals, were first described almost two decades ago, and today, there are more than 12,000 similar compounds worthy of investigation. Historically, regulations have focused on requiring testing for PFAS in water, especially drinking water, but laboratories are beginning to test for these chemicals in all sorts of products and materials — from commercial goods to personal care products to produce. Due to their potentially harmful impact on humans and the environment, regulatory agencies are now focused on creating and implementing new restrictions for PFAS, which will require providers and labs to comply with updated safety standards.

The Environmental Protection Agency (EPA) is currently leading these efforts and is working to finalize new standards for national PFAS restrictions. In 2022, the EPA set preliminary, interim health advisory limits for drinking water under its PFAS Strategic Roadmap of 0.004 parts per trillion (ppt) for perfluorooctanoic acid (PFOA), 0.02 ppt for perfluorooctane sulfonate (PFOS), and 10 ppt for hexafluoropropylene oxide (HFPO) dimer acid and its ammonium salt, otherwise known as GenX chemicals. This level of 0.004 ppt is extremely low and may require labs to update their current analytical platforms. But after rounds of feedback and listening sessions hosted by the EPA, the agency announced the proposed National Primary Drinking Water Regulation (NPDWR) with limits of 4.0 ppt for PFOA and 4.0 ppt for PFOS, which is the lowest level that can be reliably measured. However, PFAS analysis still comes with challenges for labs. One of the most significant of these is sampling and sample prep, primarily because of the large number of potential background contamination sources.

Reducing background noise for accurate samples

Many labs that study or test PFAS indicate that background contamination, or interferences that would create skewed results, is an issue because many items in their labs contain fluoropolymers, which are sources of PFAS. Contamination can also occur during the sampling and transportation process, so there is a chance that PFAS could be added to or increased within a sample before it even reaches the laboratory. However, researchers can only control what happens in the lab, and one strategy for reducing background noise is to automate sample preparation.

An example of this strategy in action is solid phase extraction (SPE), which uses a manual vacuum manifold and requires manual touchpoints. Every interaction within the SPE process using a manual manifold can potentially introduce unintended background. By using instruments that provide a closed system for the sample prep procedure, researchers can gain control over the process and ensure a more accurate sample.

Modernizing equipment for strong recovery, reproducibility

Liquid chromatography triple quadrupole mass spectrometry (LC-MS/MS) yields strong analytical insight for PFAS. These instruments are highly sensitive and consistently updated, so it is important that labs with older instruments modernize their platforms to meet the latest regulations. With so many compounds of concern, and likely more to be added to targeted screening panels in the future, effective workflow methods and high sensitivity and throughput instruments are crucial for general screening. Using modern extraction methods and instrumentation will significantly help with obtaining good recoveries and reproducibility.

Challenges differ for producers of products that require PFAS testing to ensure a safe product for consumers. Aside from the regulatory requirements for more thorough testing, facilities that produce consumables such as drinking water must address any high levels of chemicals that are identified during the QC process. Available treatment options include reverse osmosis or granulated activated carbon to remove PFAS, but not all facilities have these treatment processes in place, and recovery options can be costly for consumers.

Preparing for a new era of regulation

Drinking water is just the start of PFAS concern and the need for sensitive testing and thorough analysis will continue to grow as other matrices become prevalent, especially solids and semi-solids. As concern grows and the industry advances, strong sample preparation techniques, efficient extraction methods, and sensitive instruments will be a necessity. It will be extremely important for lab managers and producers to closely monitor changes to regulations put forth by the EPA and for new compounds of concern. Labs should consistently evaluate their technology to make sure that they can measure the required detection limits and make investments in new technology as needed.

About the author:

Chris Shevlin is a scientific and educational affairs manager at Thermo Fisher Scientific. In his current role, he collaborates with scientists on new applications, developing scientific and educational content, and working with new products and innovations. Shevlin has worked in the pharmaceutical industry, running HPLC, LC-MS, and other chromatographic methods in a technical service and QC laboratory. He earned a BS degree in biotechnology and pharmacology from the University of Buffalo and an MBA from the University of Phoenix.