As we’ve discussed in prior posts, per- and polyfluoroalkyl substances (PFAS) have historically been an important component of aqueous film forming foam (AFFF) products that are used for training and fire suppression. As awareness of PFAS in AFFF has grown over the last several years, governments at the federal, state, and municipal level, as well as industry, have sought to increase the use of “PFAS-free” AFFF. The need for AFFF without PFAS has resulted in certifications of certain AFFF products as “PFAS-free” that seek to identify AFFF products that potentially safe for environmental and health concerns.
Recently, Clean Production Action has offered an ecolabel for “PFAS-free” firefighting foam products, which they call “GreenScreen Certified Firefighting Foam.” Clean Production Action caveats that a “PFAS-free” product is defined as “less than 1 part per million (ppm) total organic fluorine as measured by combustion ion chromatography.”
What is “Total Organic Fluorine”?
Typically, analysis is performed on select individual PFAS compounds, such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), using EPA’s Method 537.1. Comparatively, measuring for “total organic fluorine” can be an alternative to measuring individually for the roughly 4,000 individual PFAS compounds. This analytical method can determine if PFAS is present (relative to the test’s detection limit capability) but it might not be able to identify which particular PFAS compound it may be. The GreenScreen Certified Frequently Asked Questions acknowledge this and state that “[t]here are some analytical testing methods that can be used to detect individual chemicals at a lower detection limit. However, these test methods only test for a small fraction of the over 4,000 PFAS chemicals that have been identified.”
In that context, it is important to note that many regulatory standards regarding PFAS substances, such as in New Jersey and those proposed in Pennsylvania, focus on individual PFAS compounds like PFOS and PFOA rather than a “total” PFAS and require detection down to the part per trillion (ppt) level (as opposed to the 1 ppm level noted above). As we discussed in an earlier blog post, New Jersey recently established establish drinking water standards for PFOS and PFOA at 13 ppt and 14 ppt, respectively. Similarly, EPA established a Lifetime Drinking Water Health Advisory Level for Perfluorooctanoic acid (PFOA) perfluorooctane sulfonate (PFOS) at a combined concentration of 70 ppt.
This comparison raises an important question: can a method that analyzes for “total organic fluorine” to the ppm or part per billion (ppb) level properly serve as an alternative analytical method when regulatory PFAS standards require detection of individual PFAS substances into the low ppt? As noted above, while a “total” organic fluorine measurement may be able to identify if PFAS is present in a substance, it may not be able to identify individual PFAS compounds necessary to adequately characterize and remediate contamination.