QUINCY, MA --A fire in August 2009 shed light on the potential problems with the combustibility of antifreeze solutions used in sprinkler systems. According to research completed by the Fire Protection Research Foundation, “under certain conditions, solutions of glycerin and propylene glycol antifreeze have been found to ignite when discharged from automatic sprinkler systems.”

This led to a significant amount of research and standards development activities to understand and mitigate this issue, which included a sunset date for legacy unlisted antifreeze solutions of September 30, 2022.

NFPA® often receives many questions around what systems need to be drained and filled with a listed solution and how to test the antifreeze. In order to help answer these questions and more, NFPA has developed a fact sheet that summarizes the requirements for antifreeze solutions in sprinkler systems that are designed, inspected, tested, and maintained in accordance with the 2023 edition of NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, as well as the 2022 editions of NFPA 13, Standard for the Installation of Sprinkler Systems; NFPA 13D, Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes; and NFPA 13R, Standard for the Installation of Sprinkler Systems in Low-Rise Residential Occupancies.

This new, free, downloadable fact sheet summarizes the requirements for new and existing systems as well as outlines the steps needed to take when testing the solutions in existing systems.