PFAS in Air: New EPA Testing Methods Reshape Emissions Management

PFAS investigations have always focused on water, soil and waste streams. Until recently.

Research shows that PFAS in air emissions could be just as impactful, maybe even more so, than leachate. And with public scrutiny and media coverage increasing, regulations are guaranteed to follow.

While official regulations for PFAS in air have been largely contained to individual states, the US EPA has introduced two methods to test and analyze PFAS in air emissions, Other Test Method 45 (OTM-45) and Other Test Method 50 (OTM-50).

OTM-45 is the first standardized method for measuring PFAS in stack emissions and OTM-50 is a complementary method evaluating products of incomplete combustion, or rather, is PFAS actually being destroyed by combustion systems, or are we just breaking it into smaller pieces?

Given the EPA introducing these methods, stricter federal regulations around PFAS in air are inevitable. Organizations that are serious about long-term risk-mitigation should use these tools now to begin addressing PFAS air pathways as part of a broader environmental strategy.

PFAS persist in the environment because they resist heat, water and chemical degradation. These properties also allow them to move between environmental media.

That persistence has driven increasing regulator and public attention toward PFAS over the past several years. While early focus centered on drinking water and soil contamination, attention is now expanding to include how PFAS move through the atmosphere and where they deposit.

Air emissions represent one pathway for that movement.

Any facility that manufactures fluorinated chemicals, produces coated materials, operates thermal destruction systems or processes PFAS-containing waste may release PFAS compounds through exhaust systems. Atmospheric transport can then distribute those compounds beyond facility boundaries.

Once that happens, PFAS is beyond a facilities control, so the best way to address PFAS in air is to do it at the source. That is where OTM-45 entered the conversation.

The EPA developed OTM-45 to measure specific PFAS compounds in emissions from stationary sources, like industrial stacks and incinerators.

With this, facilities could generate defensible data on PFAS air emissions and take the first step toward mitigation.

Organizations now use OTM-45 testing to support several practical objectives. Facilities can evaluate whether operations release PFAS through air emissions, develop emission inventories and support reporting obligations such as Toxic Release Inventory submissions.

OTM-45 was a critical first step. It established that PFAS emissions could be measured and compared across industrial processes.

However, once you’re able to measure PFAS, you then need a plan to remove or destroy it.

As facilities began evaluating thermal treatment technologies for PFAS waste streams, researchers recognized that combustion processes can break PFAS molecules apart without fully eliminating fluorinated compounds.

In these cases, high temperatures may fragment PFAS into smaller fluorinated molecules that traditional PFAS testing methods do not detect.

To better understand this process, the EPA introduced OTM-50.

Rather than focusing on the PFAS compounds measured by OTM-45, OTM-50 looks for smaller fluorinated molecules that can form when PFAS degrade during combustion. These compounds provide insight into whether combustion systems fully destroy PFAS molecules or convert them into other fluorinated byproducts.

The two methods answer different but complementary questions.

OTM-45 determines whether measurable PFAS compounds leave a facility through air emissions.

OTM-50 helps evaluate whether combustion systems actually destroy PFAS or transform them into smaller fluorinated fragments that may still persist in the environment.

Together, the methods provide a more complete picture of how PFAS behave during thermal treatment and emission control.

The progression from OTM-45 to OTM-50 reflects how environmental regulation develops.

Regulators first establish whether emissions exist. Once emissions are confirmed, focus shifts to whether treatment technologies eliminate those compounds.

That shift is already underway for PFAS.

For facilities managing PFAS waste streams or operating thermal treatment systems, the expectation is changing. Environmental teams must now evaluate both whether PFAS are emitted and whether treatment processes truly destroy them.

Regulatory frameworks are still developing, but public scrutiny and scientific focus are already here. The testing methods exist. The data can be generated today.

Organizations that act early can define their emissions profile, validate treatment performance and make informed decisions before requirements tighten.

PFAS rarely exist in a single environmental pathway. Air emissions, wastewater, residuals and treatment systems often interact across the same operational processes.

A strong PFAS air strategy begins by recognizing that connection.

Environmental teams start by identifying operations that may generate airborne PFAS, including fluorochemical processing, coating systems, waste treatment and thermal destruction technologies.

From there, targeted testing programs provide the data needed to move forward. OTM-45 identifies whether measurable PFAS compounds leave a facility through air emissions. OTM-50 evaluates whether treatment systems fully destroy PFAS or convert them into smaller fluorinated compounds.

Laboratory analysis and scientific interpretation translate these results into operational insight. Teams can evaluate treatment effectiveness, compare performance across systems and identify where mitigation strategies will have the greatest impact.

This approach shifts PFAS air testing from a reactive exercise to part of a broader, integrated management strategy that addresses PFAS across air, water and waste streams.