NFPA Establishes Sprinkler Antifreeze Requirements
An updated Safety Alert from the National Fire Protection Association addresses the use of antifreeze in new and existing occupancies. It replaces July and August 2010 Alerts that said antifreeze shouldn't be used in residential sprinklers.
An updated Safety Alert from the National Fire Protection Association clarifies when antifreeze solution may be used in both existing and new occupancies, after a fire raised questions about the combustibility of these solutions. The new Alert references four Tentative Interim Amendments (TIAs) for NFPA sprinkler standards that were issued March 1 by the NFPA Standards Council and spells out the acceptable concentrations of two specific types of solutions.
The NFPA sprinkler Technical Committees concluded the four TIAs "achieve a more comprehensive approach to the treatment of antifreeze in NFPA sprinkler standards, and provide new requirements for the use of antifreeze in both new and existing residential occupancies and in non-residential occupancies as well," according to NFPA. The four TIAs apply to:
- NFPA 13, Standard for the Installation of Sprinkler Systems (2010 edition)
- NFPA 13R, Standard for the Installation of Sprinkler Systems in Residential Occupancies up to and Including Four Stories in Height (2010 edition)
- NFPA 13D, Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes (2010 edition)
- NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems (2011 edition)
NFPA's summary indicates new sprinkler systems containing antifreeze must use only factory-premixed antifreeze solutions. The maximum allowable concentration of glycerin for a new system is 48 percent by volume, while the maximum allowable concentration of propylene glycol for a new system is 38 percent by volume. The factory-premixed solutions used in NFPA 13 and 13R systems must be provided with a certificate indicating the type of antifreeze, the concentration, and the freezing point. Factory premixed antifreeze solutions of propylene glycol in excess of 40 percent by volume are permitted in ESFR (Early Suppression Fast Response) systems where the sprinklers are listed for such use in a specific application. Factory premixed antifreeze solutions other than propylene glycol and glycerin are permitted only where they are specifically listed for use in sprinkler systems, and new systems must be annually inspected after being installed.
Existing NFPA 13D sprinkler systems must be tested annually by a qualified individual. Existing NFPA 13 and NFPA 13R Sprinkler Systems must be tested annually before freezing weather begins. "If it is determined that the solution found in the system is no longer permitted or if the type of anti-freeze cannot be reliably determined, the system must be drained and replaced with an acceptable factory premixed solution," the summary states. "If the initial tests indicate that the solution type is acceptable, test samples must be taken at the top and bottom of each system (in some cases an additional sample must be taken). If all the test samples indicate a concentration of glycerin not greater than 50% by volume or propylene glycol not greater than 40% by volume, then the solution is permitted and may remain in the system. If any of the samples indicate a concentration in excess of the permissible maximum concentrations (i.e. 50% glycerin/40% propylene glycol), the system must be emptied and refilled with a factory premixed solution."