At the August Standards Council meeting, the Council approved four Tentative Interim Amendments (TIAs) dealing with the use of antifreeze in sprinkler systems. The TIAs approved for NFPA 13 and NFPA 13R require the use of a listed antifreeze solution for all new systems. The listing for the antifreeze solution must indicate that the solution will not ignite when discharged from a sprinkler.
A similar TIA was also approved for NFPA 13D systems. The baseline requirement in the NFPA 13D TIA requires all new 13D antifreeze systems to utilize a listed solution. The difference between the NFPA 13 and 13R TIAs and the 13D TIA is that there is a requirement in the NFPA 13D TIA that permits the use of traditional antifreeze solutions, glycerine and propylene glycol, where specifically approved by the AHJ. The designer must submit documentation to AHJ that confirms that the use of a traditional solution is acceptable for that specific project. One way to do this, as noted in the annex, is to compare the design scenario to a test scenario referenced in the Fire Protection Research Foundation reports on antifreeze usage with residential sprinklers. There were no changes to the requirements for existing NFPA 13D systems.
A fourth TIA was approved for NFPA 25, addressing existing NFPA 13 and 13R systems. This TIA requires traditional antifreeze solutions to be phased out by the year 2022. This TIA also establishes several thresholds for anti-freeze solutions found in existing systems. The first threshold is set at 30% propylene glycol and 38% glycerin. Where it is determined that the antifreeze concentrations are at or below these levels, they are permitted to remain in the system until 2022. The next threshold establishes the maximum allowable concentration for existing systems.Where testing of the solution in an existing system yields concentrations in excess of 40% propylene glycol or 50% glycerin, these solutions must be drained from the system.
Where solutions are found to be between these thresholds of "safe" and "unsafe" solutions (30% and 40% propylene glycol or 38% and 50% glycerine) a deterministic risk assessment must be conducted to determine if it is appropriate to allow the antifreeze to remain in place. Similarly where solutions are drained because they exceed the maximum, "unsafe" threshold stated above, a risk assessment must be conducted to determine if a solution less than 50% glycerine or 40% propylene glycol would be appropriate. The risk assessment, as noted in the Annex, should consider the results of the testing conducted using standard spray sprinklers that is summarized in the Fire Protection Research Foundation reports.
For more information visit www.NFPA.org/antifreeze, where the TIAs have been posted and there are additional resources to address the use of antifreeze in sprinkler systems.