Yes, stack test data from other states like North Carolina (NC), New Hampshire (NH), and New York (NY) have confirmed PFAS emissions from smokestacks using a modified version of an existing test method. These sources include PFAS manufacturing facilities and large industrial users of PFAS-containing products. Similar source types have not been identified in Michigan, to date. Stack testing has not been conducted for any sources in Michigan, to date.

USEPA developed a stack test method (OTM-45) for measuring PFAS in air emitted from smokestacks. The following is an excerpt from the USEPA site on OTM-45:

"The posting of a test method on the Other Test Methods portion of the EMC website is neither an endorsement by EPA regarding the validity of the test method nor a regulatory approval of the test method. The purpose of the Other Test Methods portion of the EMC website is to promote discussion of developing emission measurement methodologies and to provide regulatory agencies, the regulated community, and the public at large with potentially helpful tools. Other Test Methods are test methods which have not yet been subject to the Federal rulemaking process."

No facilities in Michigan currently have air pollution control devices installed specifically to address PFAS emissions. Other states have installed controls for PFAS emissions including thermal oxidizers, carbon absorption, and wet scrubbers with packed bed fiber filters, to name a few. The appropriate control strategy will likely vary based on the specific PFAS chemicals involved. More research is necessary to determine if the PFAS is permanently captured and not simply transferred to other media, such as wastewater or sludge. 

For additional information, visit these sites:  

• North Carolina Department of Environmental Quality - GenX Investigation 
• New York Department of Environmental Conservation - PFAS 
• New Hampshire Department of Environmental Services - PFAS Investigation

As a “proof of concept” study, EGLE put out inexpensive, PFAS-free rain buckets at five locations Fall of 2021 and collected two to four rain events. Results showed some low levels of a few PFAS in rain and that it is possible to collect PFAS rain samples inexpensively.

At the federal level, chrome plating facilities are not allowed to add additional PFOS-containing mist/fume suppressants (above 1%) after 9/21/2015. Air Quality Division inspections of affected chrome plating sources in 2017 and 2018 showed compliance with this requirement. However, most replacement mist/fume suppressants still contain PFAS chemicals, just not the specific compound called PFOS. 

At the state level, new or modified sources of air pollutants may be required to obtain an air use permit; there are exemptions for sources with low emissions, so not all sources of PFAS air emissions are required to obtain an air permit. The sources that are required to obtain an air permit would be subject to Michigan's air toxics rules. If PFAS are emitted above certain thresholds, they would be required to meet health-based screening levels in the air before a company could be issued an air permit.  The AQD toxicologists evaluate health studies of PFAS compounds, update existing screening levels, and develop new screening levels, as appropriate.

The AQD derived health-based screening levels for PFOA, PFOS and 6:2 fluorotelomer sulfonic acid (6:2 FTS). For PFOA and PFOS, the screening levels are 0.07 micrograms per cubic meter (µg/m³) with a 24-hour averaging time. If both PFOA and PFOS are present in the air emissions, the combined concentration of these substances must be below 0.07 µg/m³ with a 24-hour averaging time. The screening level for 6:2 FTS is 1 microgram per cubic meter (µg/m³) with an annual averaging time. Screening levels are health protective values, such that if air concentrations do not exceed these levels, adverse health effects are not expected. Screening levels are designed to be protective for sensitive individuals, including children and the elderly. Additional screening levels could be developed as other PFAS are identified in future permit applications. 

• PFOS
• PFOA
• 6:2 FTS

Yes. Minnesota and Wisconsin found PFAS in outdoor air and North Carolina found PFAS in rainwater. 

• Minnesota PFAS Studies and Reports 
• North Carolina Department of Environmental Quality - GenX Investigation 

The AQD inspected all chrome platers in the state to determine PFOS use. None were using PFOS in their process; however, 28 chrome plating facilities still use PFAS substances other than PFOS. Efforts are underway to identify safer alternatives for the chrome plating industry.

AQD staff:

• will develop additional health-based screening levels for PFAS compounds, as needed, for use in air permitting.
• are learning more about how PFAS is used and estimating potential air releases.
• are also collecting information from other states, the USEPA, and the published literature on air-related PFAS issues. 
• are working with the University of Rhode Island and Harvard University to better understand atmospheric emissions and deposition of PFAS with the application of atmospheric modeling. Passive air sampling results have found low levels of PFAS in the air similar to other outdoor semi-urban areas, and at concentrations lower than indoor air samples reported in the literature. 
  • Michigan PFAS Sampling at Air Monitoring Sites (University of Rhode Island report)

As the uses of PFAS chemicals by industry are identified through air permit applications, the AQD will screen allowed emissions for potential adverse health effects as required by the air toxics rules. Appropriate air permitting measures for PFAS (such as material limits, material substitution, control requirements, emission limits and/or stack dispersion requirements) will be included in air permits, as necessary. Revisions of Part 2 air rules will be pursued to better address PFAS emissions.

On October 18, 2021, USEPA Administrator Michael S. Regan announced the agency's PFAS Strategic Roadmap, laying out a whole-of-agency approach to addressing PFAS (PFAS Strategic Roadmap: EPA's Commitments to Action 2021-2024).

In July 2022 USEPA issued a final rule to update the Toxics Release Inventory (TRI) chemical list to identify five additional PFAS subject to reporting requirements (EPA Issues Final Rule to Require Reporting on Five PFAS).

The Interstate Technology and Regulatory Council (ITRC) developed a web-based technical regulatory guidance document that “presents the necessary breadth and depth not given by the fact sheets” (ITRC Fact Sheets – PFAS) and includes stakeholder points of view, technical challenges and uncertainties, risk communication strategies, and provides links to pertinent scientific literature” on PFAS ITRC Connect.

ATSDR also maintains a web site dedicated to PFAS: ATSDR: PFAS and your health.