Class A and Class B Firefighting Foam

There are two major types of firefighting foam, Class A and Class B. Class A foams are used to extinguish fires caused by wood, paper, and brush. Class A foams generally do not contain per- and polyfluoroalkyl substances (also known as “PFAS”).

Class B firefighting foams are commercial surfactant solutions that have been (and continue to be) stored and used for fire suppression, fire training, and flammable vapor suppression at military installations and civilian facilities and airports, well as at petroleum refineries and bulk storage facilities, and chemical manufacturing plants and storage facilities. Additionally, local fire departments in communities have used and may maintain quantities of Class B firefighting foam in their inventories for use in training and emergency response.

Class B foams can be divided into two categories: fluorinated foams and fluorine-free foams. Fluorinated foams contain PFAS, and fluorine-free foams do not. Of the fluorinated foams, aqueous film forming foams or “AFFF” are the foams that contain varying amounts and mixtures of PFAS, and of the most concern to human health and the environment.

NH Fire Marshall/NHDES Joint Information Bulletin on PFAS/Class B Firefighting Foam

Class B Fluorine-Containing Firefighting Foams

AFFF foams have the potential to create an adverse environmental impact if released uncontrolled to the environment, particularly if the foam solutions reach drinking water sources, groundwater, or surface waters. PFAS contamination has been identified at many locations across New Hampshire where AFFF products were stored and/or discharged in multiple ways including but not limited to: through applications associated with fire or catastrophic events, system discharge or false activation, firefighter training, and system testing.

October 2, 2017, NHDES issued a letter to fire departments recommending that they voluntarily test on-site drinking water supply wells for PFAS. We are working with several fire departments that have identified PFAS contamination at their facilities to investigate the source(s) and extent of impacts, and develop a remedial action plan to address impacts as appropriate.

NH RSA 154:8-b Limiting Use of Class B Fluorine-Containing Firefighting Foams

NH Class B Foam Survey Report

During the 2019 legislative season, the NH Legislature adopted Senate Bill 257 relative to perfluoroalkyl and polyfluoroalkyl substances (also known as PFAS) in firefighting foam. RSA 154:8-b, effective September 3, 2019, among other things, required the New Hampshire Department of Environmental Services (NHDES) to survey municipalities throughout the state on the quantitative stock of legacy Class B firefighting foams containing PFAS.

Pursuant to NH RSA 154:8-b, the NHDES in partnership with the New Hampshire Department of Safety, State Fire Marshal’s Office (FMO) issued a Legacy PFAS Firefighting Foam (AFFF) Self Inventory Survey Letter to New Hampshire municipalities on July 31, 2020. The law further required NHDES to estimate the cost of, and institute a take-back program by July 1, 2021 for the purpose of safe and contained disposal of the legacy firefighting foams identified in the survey.

This NH RSA 154 Class B Foam Survey Report has been prepared to summarize the survey findings and provide recommendations and a framework for an AFFF takeback program.

Recommended Best Management Practices for Use of Class B Foams

NHDES AFFF Activities and Priorities

NHDES has several actions planned in order to support the firefighting community and comply with new legislation, including but not limited to the following:

  • Provide support to Fire Departments in selecting fluorine-foam alternatives.
  • Continue to evaluate disposal options and plan for a future Class B foam take-back program.
  • Provide technical support in identifying tools and resources for Fire Departments to better understand and implement best management practices for management, use, and disposal of Class B firefighting foam.
  • Once Class B firefighting foam has been discharged, work with the stakeholders to identify any impacted water supply wells and provide safe drinking water, investigate impacted media, and develop a plan to clean it up, as appropriate.

Additional Resources

To report a discharge of Class B foams containing PFAS, contact Amy Doherty of the Waste Management Division, Hazardous Waste Remediation Bureau at (603) 271-6542 or

Amy T. Doherty, P.G.
State Sites Section Supervisor
NH Department of Environmental Services
Hazardous Waste Remediation Bureau
29 Hazen Drive, PO Box 95
Concord, NH 03302-0095
Phone: (603) 271-6542
Fax: (603) 271-2181