MYTH: The laboratories are driving their PFAS detection limits lower which is driving regulatory limits lower
FALSE: Not only are labs NOT the driver of lower PFAS regulatory limits, but they are in fact the limiting factor, or more accurately the background is! When the most recent lifetime health advisories (LHA) from USEPA were released, the values were well below what laboratories can reliably detect in environmental samples. And then even more recently, the National Primary Drinking Water Regulation set the Maximum Contaminant Level Goal (MCLG) for PFOA and PFOS at 0! However, since the level of compliance for water utilities and other regulated entities needs to be measurable and practically achievable, the effective regulatory limits for PFOA and PFOS were set at 4 ng/L to match what laboratories can reliably achieve for quantitative data in the presence of background. This is the most important piece because the analytical instruments used to measure PFAS can detect many of these compounds at magnitudes’ lower levels, but in the presence of ambient background, it is difficult to discern actual environmental concentrations from what is all around us in the laboratory and even within us as PFAS are universally present in human serum.
Nonetheless, with increased sensitivity from modern instruments and improved laboratory techniques to lower background contribution and mitigate interferences, the reporting limits are beginning to drop below 1 ng/L. Will this result in the federal MCLs subsequently being lowered? It seems unlikely at this point and would require a significant undertaking. As it is, the current limits are being challenged by industry and trade associations. However, a groundwater standard that is well below the existing analytical detection limit for PFOA is being proposed by the State of North Carolina at 1 pg/L or 0.001 ng/L. The proposed limit for PFOS is closer to laboratory’s current detection limit at 0.7 ng/L. These lower limits, as they’re developed, will certainly push laboratories and the instrument manufacturers to see what is possible.
SGS is a global leader in PFAS detection and development of novel methods. When searching for a partner to provide a suitable analytical method in non-potable water and solids, the USEPA turned to SGS and selected our in-house developed procedure to be the basis for what is now the final USEPA Method 1633. When you are looking for an analytical partner you can trust, look to SGS.
To find out how we can best help you with your PFAS analysis, call +1 800 329 0204 or email PFAS@sgs.com. We look forward to hearing from you soon.
