The 2014 edition of NFPA 25, the standard for the inspection, testing and maintenance of water-based fire protection systems, was written to specifically include emergency changes regarding the use of antifreeze. Those changes were based on events in which activated sprinkler systems, fortified with antifreeze, actually intensified blazes rather than extinguished them. This was likely due to onsite errors in mixing the solutions that introduced excessive amounts of the active ingredients glycerin and propylene glycol, both of which increase flammability when present in high concentrations.
NFPA 25 is the standard for the inspection, testing and maintenance of water-based fire protection systems. Once adopted by local code bodies, authorities having jurisdiction (AHJs) require strict adherence to NFPA 25 – and frankly, there is no reason not to design, repair or maintain a system to the standard.