It’s been 10 years since NFPA guidelines specified that site-mixed, unlisted antifreeze was no longer an approved option for wet systems. Because a listed alternative wasn’t yet widely available, new systems were almost exclusively designed as a dry system.
NFPA standards require all antifreeze fire sprinkler systems to switch to a listed antifreeze by September 30, 2022. These standards help ensure that an antifreeze system performs reliably in a fire and saves more lives, rather than contributing to fire as unlisted fluids can.
Sprinkler pipes must be safeguarded when temperatures cannot reliably remain at or above 40ºF (4ºC) ambient temperature. New and existing sprinkler systems in Residential, Light Hazard, Ordinary Hazard and Storage applications can be protected against severe cold with freezemaster™ antifreeze, a new UL-listed, factory premixed freeze protection technology.