EPA ‘Drilling Down’ On Additional Method To Measure PFAS Air Emissions

• By: AWMA
• On: 10/07/2024 14:16:30
• In: Press
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By Suzanne Yohannan, Inside EPA .  Read the full article.  The method is needed to help fulfill air emission source characterization that EPA is working on, and encouraging others to conduct, as part of research on PFAS emissions from thermal destruction facilities. The research seeks to fill data gaps that EPA conceded in its updated per- and polyfluoroalkyl substances (PFAS) disposal and destruction guidance still exist.

EPA is “drilling down on” developing the new method -- Other Test Method 55 (OTM-55) -- to address sampling for non-polar, semi-volatile PFAS, Stephen Jackson, a chemist in EPA's Office of Research and Development (ORD), said on a July 24 webinar, “PFAS Analytical Methods -- A Detailed Review of Air Emission and Non-Potable Water Test Methods.” The Air & Waste Management Association sponsored the webinar.

In particular, a method is needed for measuring FTOHs and potential PICs and other nonpolar, semi-volatile PFAS that EPA suspects are harmful to human health and the environment, according to Jackson.

“We're committed to getting this done because” these PFAS could be harmful to human health and because the agency in the updated PFAS destruction guidance includes “placeholders” for the OTM-55 method in an appendix, Jackson said.

It is unclear at this point, however, how comprehensive OTM-55 will be, Jackson said in a follow-up response. At a minimum, EPA will be looking for PICs from incineration systems containing fluorinated wastes, he said. The agency is “currently weighing the pros and cons” of combining the product of incomplete destruction (PID) targets and FTOHs/other neutral PFAS all in one method, or separately, he said. Also, to address unknowns, EPA will try to include an unknowns analysis in the method in order to help assess how well its target list overlaps with what semi-volatile organic compounds are being emitted, similar to how it did in another method known as OTM-50, he said.

In the updated destruction and disposal guidance, EPA found that uncertainties and data gaps remain over disposal and destruction technologies' protectiveness even as it highlighted methods such as interim storage, permitted hazardous waste landfilling, underground injection control and certain thermal treatment as less likely to pose environmental impacts than other methods while acknowledging their limitations.

The guidance's appendix provides a separate guidance for conducting air emissions field testing at commercial thermal destruction facilities -- signaling EPA is continuing to try to fill data gaps to determine whether thermal treatment such as incineration can fully destroy PFAS. The appendix, titled “EPA Guidance to Conduct PFAS Emissions Field Testing at Commercial Thermal Destruction Sources,” outlines recommendations for how technology providers and others can conduct field tests on PFAS emissions from incineration and other thermal destruction technologies as it seeks to fill the data gaps on whether full-scale technologies can fully destroy the substances.

Growing Need

The additional method would add to the emerging arsenal of PFAS air emissions testing methods -- OTMs -- EPA is developing to provide the tools needed for thermal destruction technologies' field testing. OTMs are not finalized methods that have been subject to the federal rulemaking process, but are formal methods based on the best available data at the time, Jackson said.

The work on the method comes as the need for PFAS destruction and disposal methods grows in the wake of two major EPA rules under drinking water and waste laws that target the chemicals.

Specifically, EPA's ORD is conducting PFAS thermal destruction emissions characterization research to improve the agency's understanding of how PFAS behaves with respect to waste incineration and thermal treatment and thermal destruction emissions control technologies, the appendix says. It outlines goals for field tests that could be followed by any entity conducting this work in concert with EPA or independently, including the goals of confirming if thermal treatment can destroy PFAS through conventional destruction and removal efficiency testing, and characterizing potential PICs and products of incomplete destruction.

The guide recommends sampling protocols to characterize air emission sources including existing methods OTM-45 and OTM-50, the latter of which was issued in January, to address polar semi-volatile and nonpolar volatile PFAS, respectively.

In addition, it calls for collecting samples “for other semivolatile target compounds using methods SW-846[,] Methods 0010/3542/8270 with the inclusion of the Method 8270 procedure.” Jackson during the webinar pointed to this paragraph in the appendix, saying, “you can see in this note here that methods 0010 and 8270 -- basically placeholders for [OTM-]55 -- are included in the guidance. So, it's something that the agency thinks is important for ongoing research so we want to get that done.”

According to slides Jackson presented on the webinar, the new method being developed will be based on Methods 0010/3542/8270. These are the sampling, sample preparation, and analysis techniques, respectively, that EPA will likely use or slightly revise to comprise OTM-55, Jackson said in the follow-up response.

In a slide outlining his concluding points, Jackson said that “accepted PFAS and PFAS-related emissions measurement methods are needed for multiple purposes” and OTMs fit this requirement, noting that EPA is accelerating development of what will be OTM-55.

At the same time, the agency recently updated OTM-45, which is used to sample for polar semi-volatile PFAS, addressing when lab materials containing the fluoropolymer polytetrafluoroethylene (PTFE) can be used, and modifying conditions for testing GenX chemicals, among other revisions.

The agency in January released the long-awaited OTM-50, an analytical air emissions test method that EPA says in the destruction and disposal guide will help it better characterize PICs to aid in addressing uncertainties when additional data are collected. OTM-50 measures a set of 31 volatile, nonpolar fluorinated compounds, such as PFAS, in air emissions, including PICs and PIDs.

Further, Jackson's key points slide says EPA is placing a major focus on applying these methods to thermal treatment, incineration and combustion sources, and he noted that accessing “actual sources to evaluate methods and conduct comprehensive source characterizations is critical.” -- Suzanne Yohannan (syohannan@iwpnews.com)