Antifreeze Update

It has been over two months since the NFPA Standards Council issued Tentative Interim Amendments to NFPA 13, 13D and 13R banning the use of antifreeze in new sprinkler systems protecting dwelling units (See eTechAlert No. 187 – August 17, 2010). The NFSA petition to the NFPA Board to overturn the TIAs was denied based on “no extraordinary circumstances that would require the intervention of the Board of Directors.”

In its August 5th decision, the Standards Council had advised the “relevant committees” to “consider this question in a coordinated manner and report back to the Council no later than its October 2010 meeting with any proposed actions or recommendations.” The Standards Council is holding its October meeting today and tomorrow in San Antonio, Texas. What is the current status of the effort to have the various NFPA technical committees address key issues of allowable concentrations, non-dwelling occupancies and existing systems?

A task group of the Automatic Sprinkler Technical Correlating Committee (TCC) met by teleconference and at the end of September delivered their recommendations to the NFPA 13 Installation Criteria Committee, the NFPA Residential Sprinkler Committee (for 13D and 13R), and the NFPA 25 Committee on Inspection, Testing and Maintenance. These committees are in the process of having their own teleconferences in order to address the TCC task group recommendations by the end of October.

What did the TCC task group recommend? Their recommendations can be summarized as follows:

  • TIAs to be issued on older editions of the NFPA standards as well as the current editions
  • TIAs to address all systems, not just those protecting dwelling units
  • Only factory premixed antifreeze solutions to be allowed
  • For new systems, maximum concentrations by volume of 35% propylene glycol or 45% glycerin, except that 40% propylene glycol and 50% glycerin be permitted where maximum static and flowing pressures do not exceed 80 psi, and higher concentrations for ESFR systems when specifically listed for such applications. Special listed antifreeze solutions would also be permitted.
  • For existing systems, testing of the existing solution, and replacement of solutions exceeding 40% propylene glycol or 50% glycerine with premixed solutions not exceeding such concentrations. Drops not exceeding 36 inches in length would not be required to be drained unless the antifreeze type is changed. Special listed antifreeze solutions would also be permitted. In existing non-residential occupancies, antifreeze systems not exceeding 40 gallons capacity protecting normally unoccupied spaces would be allowed to remain in service regardless of antifreeze type and concentration. Examples might be attics, trash enclosures, crawl spaces, isolated storage areas, industrial equipment areas and dust collectors.

The TCC is also recommending additional research to investigate factors of operating pressures, short duration discharges, and antifreeze flow characteristics.

As the various committees consider the TCC task group recommendations, they will likely make their own recommendations. The NFPA Standards Council is next scheduled to meet in March of 2011, but they have indicated they will consider an emergency meeting to address this issue.