Addressing the concern of ground water contamination by perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) chemicals, the U.S. Congress moved to enforce strict restriction on the testing and use of aqueous film forming foam (AFFF). Further to this action, Congress has put in place mandates that prohibit the use, or purchase, of AFFF by 2024 in shore-based applications only. The Department of Defense and industry now face a demanding challenge to identify and prove that a new firefighting foam replacement to AFFF can meet the performance standards set forth in the Mil-Spec standard. A replacement must be free of PFOS/PFOA, or any other harmful chemical. This is a demanding challenge, to find a replacement that is both high preforming and safe for the environment.

The objective of this project was to provide test data to support Compressed Air Foam (CAF), a foam making process that when used with a PFAS-Free Foams (PFF) has shown to be effective in firefighting for aviation, naval, and military applications and can meet all fire performance requirements of the MIL-F-24385 test protocol. PFF products offer a solution thats better for the environment than AFFF, but often have difficulty in meeting the fire performance requirements of Mil-Spec. Rate of application is often required to be greater than that of traditional AFFF. An alternative foam making process using CAF will strengthen the performance of a PFF product by generating a higher quality finished foam.

Technology Description

CAF, a foam making process, is a mechanical method used to produce a finished foam. In the process, compressed breathing air or nitrogen gas is injected into the foam/water solution in a device known as a mixing chamber. This project looked to optimize the performance of PFF/CAF to the requirements of MIL-F-24385 at Mil-Spec rates of application and lower using several PFF manufactured foams.

Demonstration Results

As tested, CAF with PFF does meet the proposed new Mil-Spec. CAF will provide no less than 30% greater performance with low grade fuels like Aviation Gasoline Product and Jet A1, with up to 100% greater performance on higher grade fuels such as non-ethanol gasoline over conventional foam making process.

Implementation Issues

Recommendations resulting from this research include:

  • Continued research of PFF/CAF for Military applications.
  • Promoting further development of PFF/CAF based solutions.