NFPA 25 2026 Edition – How Does This Impact Dyne Test Reports? - October 2025

by Alyssa Dunn, General Manager

The 2026 edition of NFPA 25 has officially been released. A copy of this new edition can be viewed at nfpa.org. There are a few changes from the 2023 edition to the 2026 edition that may impact your Dyne test reports.  

Sprinkler Testing

One of the major changes to testing requirements comes from the addition of section 5.3.1.1.1.7.

Where sprinklers have been installed for 50 years in dwelling units, one of the following shall occur

1. The sprinklers shall be replaced with fast-response sprinklers.
2.  Representative samples of the sprinklers shall be tested for thermal sensitivity such that the RTI does not exceed 65 (meters-seconds)1⁄2.

A dwelling unit can be defined as “One or more rooms arranged for the use of one or more individuals living together, as in a single housekeeping unit normally having cooking, living, sanitary, and sleeping facilities that include, but are not limited to, hotel rooms, dormitory rooms, apartments, condominiums, sleeping rooms in nursing homes, and similar living units” according to NFPA 25 2026 Edition Section 3.3.11.

Essentially, if you have a building where individuals could be living, the sprinklers in that living area should be fast response sprinklers or pass the RTI requirements for fast response sprinklers. Dyne will be adding a disclaimer to the sprinkler test report indicating if the sprinkler is from a dwelling unit, it should have an RTI that does not exceed 65 (meters-seconds)1⁄2 according to NFPA 25 2026 Edition Section 5.3.1.1.1.7. You will find both the response time and RTI results for each sprinkler on your test reports.

Although not directly related to a change on your test report, NFPA 25 2026 Edition now includes the requirement that “sprinklers affected by a fire as determined by the AHJ” shall be replaced in accordance with 5.4.1.1 (4).

Antifreeze Testing

The 2026 edition of NFPA 25 updated some of the wording for antifreeze solution testing, but the requirements remain the same. Annual testing is still required toward the beginning of the heating season prior to the onset of freezing conditions according to section 5.3.4.

Further clarification is provided regarding existing systems in section 5.3.4.4.2.

An existing nonlisted antifreeze solution that tests with its specified concentration shall be permitted to remain in an existing system if the concentration of premixed antifreeze solution is limited to 30 percent propylene glycol by volume or 38 percent glycerine by volume.

This is not a change from the previous edition, but the 2026 Edition emphasizes nonlisted solutions can remain in service in existing systems provided they still test with specific concentrations.

Foam Concentrate Testing

There were no major changes to the foam testing requirements in the 2026 edition of NFPA 25. Annual testing of foam concentrates is still required according to section 11.3.1.1.