Fire Protection Antifreeze Systems

The coming of winter requires building owners and managers to review their buildings and systems for protection against freezing. However, there is one building system that may already be freeze protected and should be reviewed due to recent developments — sprinkler antifreeze systems.

Based upon reports of a fire incident involving a sprinkler system that contained a high concentration of antifreeze solution, the National Fire Protection Association (NFPA) began researching and testing the possible effects of antifreeze use in sprinkler systems. Beginning in March 2011 the NFPA began issuing Tentative Interim Amendments as well as updating several NFPA sprinkler standards to address these issues.

Contained in these various publications are several items in particular which should be noted:

  • New sprinkler systems (defined as those installed after September 30, 2012) containing antifreeze are required to use “listed” antifreeze solutions. This “listing” must indicate that the solution will not ignite when discharged from a sprinkler.
  • Existing sprinkler systems (defined as those installed before September 30, 2012) containing antifreeze must be tested annually, prior to the start of winter. In addition, these systems must be upgraded with “listed” antifreeze solutions by September 2022 or replaced with alternative freeze protection methods.

At present, there are no commercially available listed antifreeze solutions. This creates numerous complications for facilities utilizing sprinkler antifreeze systems installed after September 30, 2012. Adding further complication to this issue is the fact that that not all Jurisdictions are interpreting or enforcing these requirements uniformly.

While this is by no means a complete list of all the latest NFPA requirements or potential system exceptions, it will hopefully be a starting point for review as to whether your existing sprinkler system is in compliance with current requirements. The current requirements for sprinkler systems containing antifreeze can be accessed via the NFPA website. In addition, it is recommended that the local authority having jurisdiction be contacted to determine their current requirements relating to sprinkler antifreeze systems.

If you have any questions or have a project with which we can assist you, please do not hesitate to contact Bob Haney, PE at (814) 237-2180 or