By Grant Lobdell, President
Corrosion occurs in all fire protection sprinkler systems. Corrosion damage/products and mineral deposits can restrict water flow and impair mechanical operation, leaving facilities vulnerable. For these reasons, the 2025 edition of NFPA 13, Standard for the Installation of Sprinkler Systems, requires the following during system installation:
5.1.4.1 Water supplies and environmental conditions shall be evaluated for the existence of microbes and conditions that contribute to microbiologically influenced corrosion (MIC).
5.1.4.2 Water supplies and environmental conditions shall be evaluated for conditions that contribute to unusual corrosive properties.
The 2026 edition of NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, then requires an assessment of the internal condition of the piping at a minimum of every 5 years. As part of this assessment:
14.2.1.3 Tubercules or slime, if found, shall be tested for indications of microbiologically influenced corrosion (MIC).
Our testing service can help you meet these requirements. What’s more, our service can also be used to evaluate remediation efforts (e.g. nitrogen, biocide, etc.) that may have already been taken or will be taken to prove they remain effective over time.
Corrosive Properties
No further guidance is given in regard to test methods or requirements in these NFPA standards. For that, we must look to other industry standards and white papers. Among them, FM Global’s Research Technical Report from 2014, Corrosion and Corrosion Mitigation in Fire Protection Systems, is one of the most in depth and fairly recent. According to this report:
The corrosivity of sprinkler water in [a fire protection system] is significantly influenced by water quality and chemistry parameters, such as concentration of dissolved gases (O2), dissolved anions (chloride, sulfate, etc.), pH, alkalinity (HCO3- and CO32-), solids (hardness and deposits), and microorganisms.
Our service includes an analysis of all the parameters mentioned above.
Microbiologically Influenced Corrosion (MIC)
At Dyne Fire Protection Labs, an NFPA Global Solutions Company, we are bringing qPCR (quantitative polymerase chain reaction) technology to the fire protection market. qPCR is the go-to technology already in use in other markets (pharmaceutical, oil & gas, etc.) for quickly and accurately amplifying (thermal cycling) and then quantifying (fluorescence) targeted DNA. As a result, MIC results can more accurately be produced in hours instead of days/weeks, as is common with the incubation methods in the market today.
Sampling
While not explicitly required, consider sampling the water that is currently in the system (before draining) and the water that will be going into the system after draining (water supply). By doing so, you will be able to get a more complete picture of what may be going on in your system – currently and after refilling.
We include a preservative buffer with all FREE corrosion & MIC sample kits to combat the challenges of shipping microbial samples. Changes in environmental conditions (e.g. temperature) during shipping can significantly impact the microbes in solution. Some may like the different environment and multiply in transit, others may not and die out. One way to combat this is to ship water samples overnight on ice. However, this can be quite cumbersome and costly. Instead, the preservation buffer included in our FREE corrosion & MIC kits suspends the microbes in the state they were found when the sample was pulled.
Order your FREE corrosion & MIC sample kits to get started today!
Questions? Contact us today by calling (800) 632-2304 or emailing dyne.lab@nfpaglobal.com.
©Dyne Fire Protection Labs 2026