In 2009, fire protection professionals changed their views of antifreeze sprinkler systems. That was the year that a woman was killed, and four others were injured when a kitchen grease fire caused a sprinkler system, containing antifreeze solution, to discharge. The antifreeze solution in the system was determined to be 71.2% glycerin and water. It ignited when discharged causing a deadly explosion. Prior to this incident, it was common practice to mix antifreeze solution in the field to charge a system.
Because of this event, several changes were made to the NFPA codes including the following:
- NFPA 13, Sprinkler Systems, 8.6.2.1 required antifreeze solutions to be listed for use in sprinkler systems. This eliminated the use of solutions mixed on site.
- The concentration of antifreeze solution has been limited to 38% and 30% by volume for glycerin and propylene glycol, respectively for most applications.
- A placard is now required specifying 1) the locations of antifreeze, 2) the antifreeze manufacturer and 3) the concentration and volume of antifreeze in the system.
NFPA 25, Inspection, Testing and Maintenance of Water-Based System, Section 5.3.4 requires annual testing of the antifreeze in the system. The specific gravity or refractive index shall be measured to determine the concentration of the antifreeze solution. If the concentration is outside the allowable range, the solution must be drained and replaced with a listed solution.
Dyne offers laboratory testing of antifreeze in sprinkler systems and the laboratory testing goes above and beyond the testing that can be conducted in the field. Dyne can:
- Confirm not only the concentration but the type of the solution i.e., glycerin or propylene glycol.
- Verify whether the solution is a listed antifreeze solution.
Though laboratory testing is not a requirement of NFPA codes for Antifreeze Systems (field testing is acceptable), it may give you peace of mind to not rely on the paperwork and documentation for what type of solution is in the system by giving you absolute confirmation.
If you have any questions regarding this article, please contact Dyne Fire Protection Labs at lab@dyneusa.com or (800) 632-2304.
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