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PFAS-Containing Firefighting Foam

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a large group of human-made chemicals that have been used in industry and consumer products worldwide since the 1950s. PFAS have been used specifically in some synthetic Class B firefighting foams, including aqueous film-forming foam (AFFF). For additional details, read the Interstate Technology & Regulatory Council (ITRC) Aqueous Film-Forming Foam (AFFF) fact sheet.

Image of the firefighting foam poster for Wisconsin fire departments.
Poster for Wis. fire departments.

Poster for Wisconsin Fire Departments

The Wisconsin DNR created a poster about firefighting foam and PFAS for Wisconsin fire departments. Download the poster or email if you would like printed copies for fire stations.

Fluorine-Free Firefighting Foams

A few organizations offer lists of what are believed to be fluorine-free firefighting foams, including:

The DNR does not endorse or confirm the validity of claims that foams listed by other organizations are fluorine-free. Firefighting agencies may wish to contact these organizations directly to evaluate their claims. It may also be productive to work with foam manufacturers and their vendors to inquire about specific products and request fluorine-free certifications or other evidence of PFAS-free ingredients.

The U.S. Department of Defense is engaged in ongoing research on fluorine-free foams.

Use of Foam

Restrictions on Use

Section 299.48, Wis. Stats. prohibits the use of Class B and Class A/B firefighting foams that contain intentionally added per- and polyfluoroalkyl substances (PFAS), except in the following two situations:

  1. when used as part of an emergency firefighting or fire prevention operation; and
  2. when used for testing purposes at a testing facility that has implemented appropriate containment, treatment and disposal or storage measures to prevent discharges of the foam to the environment and does not flush, drain or otherwise discharge the foam into a storm or sanitary sewer. Information about appropriate containment, treatment and disposal or storage measures is found in ch. NR 159, Wis. Adm. Code.

Foam Use For Training

The use of firefighting foams with intentionally added PFAS is explicitly prohibited for training purposes. Training means providing first-hand field experience to a person who may use a firefighting foam as part of an emergency firefighting or fire prevention operation.

Notification Requirements When Class B and A/B Foam Is Used

Section 292.11(2), Wis. Stats., requires fire departments to notify DNR immediately when PFAS-containing foams are discharged to the environment.

Call the 24-hour emergency hotline at 1-800-943-0003 to report firefighting foam spills and discharges.

Documentation Requirements

Fire departments are required to retain manufacturers' safety data sheets (SDSs) for all Class B and A/B firefighting foams they possess. When reporting foam discharges, fire departments must make these SDSs available to DNR for examination.

  1. when used as part of an emergency firefighting or fire prevention operation; and
  2. when used for testing purposes at a testing facility that has implemented appropriate containment, treatment and disposal or storage measures to prevent discharges of the foam to the environment and does not flush, drain or otherwise discharge the foam into a storm or sanitary sewer. Information about appropriate containment, treatment and disposal or storage measures is found in ch. NR 159, Wis. Adm. Code.
    • When PFAS-containing firefighting foam is used as part of an emergency firefighting or fire prevention operation, notify DNR immediately or as soon as practicable without hindering firefighting or fire prevention operations.
    • When PFAS-containing firefighting foam is used for testing purposes, notify DNR immediately of any discharge of foam to the environment.

Rulemaking and Public Input

Permanent Rule NR-159: Management of Firefighting Foam that Contains PFAS

2019 Wisconsin Act 101 required the department to promulgate rules to implement and administer s. 299.48, Wis. Stats., including to determine appropriate containment, treatment and disposal or storage measures for testing facilities.

The DNR developed permanent rule ch. NR 159, Wis. Adm. Code, related to firefighting foam that contains PFAS. This rule reflects the version of the emergency rule as suspended by JCRAR on December 18, 2020. Some firefighting foams currently used to extinguish flammable liquid fires, such as Class B and Class A/B foams, include intentionally added PFAS, meaning PFAS is a constituent of the foam. This rule is primarily concerned with preventing the discharge of these foams to the environment.

Foam Collection and Disposal

Collection and Disposal of Fluorinated Foam

The DNR, in partnership with the Department of Agriculture, Trade and Consumer Protection (DATCP), was provided with $1 million in the 2021-23 state budget for a collection and disposal program for fluorinated firefighting foam. The DNR and DATCP, with the assistance of professional firefighting associations and local fire departments, identified at least 25,000 gallons of unwanted PFAS-containing firefighting foam at fire stations throughout Wisconsin. Collection of this foam for disposal is currently underway.


February 2022

  • Release of funding for foam collection and disposal program by the Legislature for joint administration with Dept. of Agriculture, Trade and Consumer Protection

April 2022

  • Outreach to fire departments across Wisconsin to determine the quantity and distribution of fluorinated firefighting foam waste ready for collection

May and June 2022

  • Development of collection and disposal program and contract requirements

July 2022

  • Release of Request for Bids (RFB) on VendorNet

September 2022

  • Award North Shore Environmental Construction, Inc., a Wisconsin-based company, as the contractor with lowest bid to collect and dispose of fluorinated firefighting foam waste

October 2022

  • Begin collection of fluorinated foam for safe disposal

February 2023

  • Gov. Evers proposes an additional $1 million in the draft 2023-25 state budget

March 2023

  • Completed first round of foam collection and disposal. In total, North Shore Environmental Construction, Inc. collected over 28,000 gallons of foam waste from more than 60 counties
  • Additional outreach to fire departments about a second round of foam collection for disposal

Questions about the fluorinated firefighting foam collection and disposal program can be directed to


Fire Chiefs Questions and Answers

The following is a list of questions that have been asked by various representatives of fire departments within the state of Wisconsin and includes questions from two Wisconsin State Fire Chiefs Association meetings held in February 2020 regarding PFAS-containing (fluorinated) foam. As more questions on this topic are addressed by DNR staff, they will be added to this FAQ list. The questions below are also available for download and printing.

For non-emergency discharges of fluorinated (PFAS-containing) foam, can fire departments use the email form to notify the DNR? The email form does not currently include PFAS as an option. The DNR should define which scenarios require emergency call-in reporting and which could be handled with the email form.

Yes, fire departments should submit DNR webform 4400-225 to report historical, residual hazardous substance discharges that are discovered through laboratory analyses of environmental media (e.g., sampling discolored soil near a foam storage area when the date of the discharge is unknown). Form 4400-225 is accessible through the RR Submittal Portal application. Visit the RR Program Submittal Portal webpage for directions using the form and to launch the application.

In the event of a new, present-day discharge of fluorinated foam to the environment (e.g., use of AFFF to extinguish a large chemical fire), an immediate notification is required by calling the Wisconsin Emergency Hotline at 1-800-943-0003.

In an emergency fire situation where fluorinated (PFAS-containing) foam is discharged for fire suppression, who will be considered the" spiller" or "discharger" of the foam? Will fire departments be responsible parties? What about property owners? Causers of the fire?

Under s. 292.11(3), Wis. Stats., the party responsible for a hazardous substance discharge to the environment can be the person that possesses, controls, or causes the discharge. If fluorinated foam is discharged as a result of a fire suppression activity, the person that owns the vehicle, structure and/or property that was on fire may be considered the responsible party as the possessor of a discharge of a hazardous substance. Also, the person or entity that caused the fire would be considered a responsible party as a "causer" of the incident that led to a hazardous substance discharge. Whenever possible, the DNR requires the person or entity that causes the discharge of a hazardous substance to take the appropriate response actions.

The DNR recommends that fire departments work cooperatively with the responsible party, the DNR and any environmental consultants that are hired to minimize fluorinated foam discharges to the environment—for example, working cooperatively with the environmental consultant hired by the responsible party or the DNR to mitigate the migration of foam into utilities, waterways and soil. Responsible parties should consult s. NR 708.05, Wis. Adm. Code, for immediate action response requirements.

Additional discussion of responsible party determinations is in the response to question 5 below.

Would it not be more appropriate for the fire departments to complete the foam cleanup and then bill the responsible party?

Fire departments may or may not have authority to bill (recover costs from) the responsible party after responding to a foam cleanup effort. The responsibilities of each entity involved in a fire event will vary depending on the facts and site-specific scenarios. The DNR recommends that fire departments do whatever is practicable given the situation and its resources at the time to minimize and mitigate impacts from the discharge of fluorinated foam into the environment, and to notify the DNR immediately.

What are the processes fire departments must follow after a discharge of fluorinated foam is reported? Where can they get guidance on these topics? Is a fire department going to be in a position to recapture spent foam?

Fire departments should work cooperatively with the identified responsible parties, the DNR, and any environmental consultant hired to minimize impacts to human health and the environment to the extent practicable, at minimum in accordance with s. NR 708.05, Wis. Adm. Code. This typically includes limiting and containing the foam discharge and keeping the foam from entering surface waters, sewers, and other utility corridors, until an environmental consultant arrives to conduct mitigation, investigation, and cleanup work. Beginning Sept. 1, 2020, appropriate containment, treatment and disposal or storage measures for foam containing PFAS may not include flushing, draining or otherwise discharging the foam into a storm or sanitary sewer. After the discharge is reported to the DNR, the DNR spill coordinator will contact the incident commander to provide advice and assistance.

What if a fire department uses a fluorinated foam on a structural fire that doesn't require the use of fluorinated foam? Is the owner of the structure or the fire department the responsible party for the foam discharge?

Fire departments may want to reconsider the necessity of the use of fluorinated firefighting foams when the fire situation does not otherwise warrant such use. There may also be additional reasons to reevaluate foam-use choices in certain situations (e.g., environmental, legal, etc.) and the possible post-use implications. As noted in the answer to a previous question, the DNR has clarified who they generally consider a Responsible Party (RP) in such a situation. However, the property owner may be concerned about the use of such fluorinated foams if they are not otherwise warranted. The DNR encourages the reduction and/or elimination of the use of fluorinated foams in situations where they are not needed.

Is PFOA-free and PFAS-free the same thing?

No. PFOA is one distinct PFAS compound out of thousands of PFAS substances. "PFAS" stands for per- and polyfluoroalkyl substances, which is an umbrella term for a class of several thousand such compounds. PFOA, which stands for perfluorooctanoic acid, is one of the most commonly studied and referenced PFAS compounds (along with perfluorooctanesulfonic acid, or PFOS). These were two of the original PFAS substances developed in the 1940s. Most modern fluorinated foams (i.e., those manufactured before 2003) contain little or no amounts of PFOA and PFOS, but these foams are still an environmental and human health concern due to other PFAS ingredients. PFOA and PFOS may also still be in fire department equipment or storage tanks that once contained older versions of fluorinated foam. Even if the foam concentrate container label states PFOA- or PFOS-free, the foam may still contain intentionally added PFAS - likely those PFAS developed more recently to replace PFOA and PFOS. The DNR recommends all fire departments inventory their fluorinated foam and work with the manufacturer and professional fire associations to know their products.

For fire departments considering getting their current foam or an alternative foam sampled and analyzed: What analysis should I use? What do the analysis results mean? Who can help with interpreting the sample results?

Due to the proprietary nature of firefighting foam formulations, foam manufacturing companies usually do not disclose what specific chemical compounds are included in their foam product formulas, and as a result, may not include PFAS ingredients on their Safety Data Sheets (SDS). Some foam manufacturers market products as "fluorine-free" or "PFAS-free," but these claims may not be accurate. Foam analysis at a DNR-certified environmental laboratory may be necessary to identify which foams are considered "PFAS-free." The DNR does not endorse or recommend any brand or firefighting foam products.

The following DNR foam sampling suggestions are only for a fire department's consideration, and these suggestions may be updated from time to time based upon new or additional information provided to the DNR:

  1. Ideally, PFAS sampling of foam should include for the current Wisconsin analyte list. Some laboratory analyses can also determine the level of total organic fluorine in a foam product, but at significantly higher detection limits and using non-certified methods.
  2. If you get your foam sampled for PFAS and need assistance interpreting the results, contact Jason Lowery.
Can DNR conduct foam sampling?

Several laboratories are working with the DNR to obtain certification to analyze for PFAS. The DNR will accept PFAS results from all of these laboratories while they undergo the certification process. To obtain the lowest PFAS detection limits, foam analysis should be done using an EPA Modified 537 Method for Wisconsin's list of 36 PFAS analytes of concern.

Why doesn't DNR procure a list of safe foams? Why should every department conduct sampling if other fire departments have already sampled the same product? Can the DNR develop a directory of sample results so that we are not duplicating effort?

The DNR agrees that a centralized list of foams with lower PFAS concentrations would be beneficial. Below are links to publicly available websites with information about foams with purportedly lower PFAS concentrations. The DNR has not verified the accuracy of any of this information, nor is the DNR affiliated with any of the organizations below.

Foams marketed as "PFAS-free" may still contain measurable concentrations of PFAS. For example, one foam certification group requires a total organic fluorine concentration of < 1 part-per-million to be labeled as PFAS-free. However, the DNR, other states and the EPA are using the measurement of parts-per-trillion for PFAS standards. For example, 1 ppm of PFOS is the equivalent of 1,000,000 ppt. The Wisconsin Department of Health Services (DHS) has proposed an Enforcement Standard of 20 ppt for the total PFOA-plus-PFOS concentration, which is significantly lower than 1 ppm.

PFAS C6 foam products are advertised by some manufacturers as a "green option." Are they a green option?

Class B (and class A/B) AFFF and AR-AFFF foams are all currently manufactured with intentionally added PFAS. Some new foams are being sold as "fluorine-free" foam, which do not contain intentionally added PFAS and may work effectively on most types of flammable liquid fires. However, the foam concentrate label must say FFF (fluorine-free foam), F3, or fluorine-free specifically to ensure no PFAS ingredients are included. So-called C6 foam products contain PFAS.

If a Class B or A/B foam concentrate label does not specifically state that the foam is fluorine-free, the foam likely contains PFAS. Some C6 foam products are more water-soluble and travel farther in groundwater. The C6 foams tend to be concentrated at higher levels to match the effectiveness of the older C8 foams. For all these reasons, the C6 foams may be just as harmful to the environment and public health as the original C8 foams and should not be considered a "green" nor "sustainable" option.

Where are the sample results for the DNR's class A foams that show they are PFAS-free? How do we know if the DNR's Class A foams have 'intentionally added PFAS?'

The following documents are a copy of the sample results and a paper on class A firefighting foam that the DNR uses.

Why is all of the attention on fire departments – what about other PFAS sources?

When fire departments respond to large chemical fires, they utilize a significant volume of water that is generally uncontrolled. When they use PFAS-containing foam to respond to a Class B fire, that foam and water contain highly concentrated levels of PFAS. Thus, fire departments are a focus at this time because of the ongoing use of fluorinated foam by fire departments and confusion about what PFAS compounds are in which fluorinated foam products. Fluorinated foam continues to be used in ways that can result in significant discharges of PFAS compounds into the environment. No other ongoing use of PFAS-containing materials or products of which the DNR is aware has the potential to regularly result in substantial PFAS discharges to the environment.

In addition to assessing ongoing materials usage that has the potential to result in new PFAS discharges, the DNR continues to assess and investigate legacy PFAS contamination. This includes properties and areas with past fluorinated foam use or training, including airports, Department of Defense locations, and petroleum and oil refining and storage areas. The scope of the DNR's PFAS work goes far beyond fire departments.

Legacy contaminant areas also include historical manufacturing and disposal areas, such as:

  • textiles, including leather, clothing and carpets;
  • furniture, including upholstery;
  • electroplating and metal fabrication;
  • specialty paper;
  • paint manufacture, storage and handling;
  • chemical manufacture, storage and handling; and
  • landfills.
Is it possible for sampling and analysis to keep up with changes in formulations?

It is possible with current technology to randomly sample and analyze product formulations from major distributors of firefighting foams. If any PFAS are intentionally used in a foam formulation, they are typically present in levels that are easy for certified laboratories to detect. Most instrumentation can identify PFAS on the ppt level, and rapid screening techniques are becoming available that will allow even more widespread analyses in coming years.

Is the FAA instructing airports to use PFAS foams until 2020?

Fluorinated foams are required at FAA airports until October 2021 as a result of the FAA Reauthorization Act of 2018 (HR302); the FAA has been directed to stop requiring the use of fluorinated foam no later than October 2024. Fluorinated foams may still be used for emergencies and also for testing equipment in Wisconsin. By state law, intentionally added PFAS-containing foam may not be used in Wisconsin for training purposes as of September 1, 2020. Compliance with both FAA and Wisconsin regulations is possible because FAA does not require the use of fluorinated foams for training purposes. We recommend seeking any clarifications or verifications on this topic at

What is the process for removing class B foam from engines and decontaminating the tank?

Professional firefighting associations, the FAA, and US Department of Defense facilities may have best practice guidance available for decontamination of equipment. Since the process may vary depending on the types of foam and equipment used, we recommend that fire departments request assistance from qualified environmental contractors to identify an appropriate decontamination process. Decontamination processes recommended by such contractors often utilize detergents and multiple rinses for the equipment and a de-foaming agent in the wastewater containers before disposal.

How can fire departments dispose of fluorinated foam?

In 2022, the DNR and the Department of Agriculture, Trade & Consumer Protection (DATCP) will be contracting with a third party to collect and dispose of fluorinated firefighting foam. Fire departments that have fluorinated foam for disposal should watch for communications from their professional associations about this upcoming collection opportunity. Questions about fluorinated foam collection and disposal and how to participate can be submitted to


Additional Information and Resources

The DNR intends to maintain a partnership with the Wisconsin State Fire Chiefs Association, the Wisconsin State Firefighters Association and all Wisconsin fire departments to address this issue. Resources, information and guidance will be posted below as they become available.