MIC (Microbiologically Influenced Corrosion) is a serious problem in Wet and Dry Fire Sprinkler Systems.

Introducing FSS-ProGuard 295UL the first and only UL Listed corrosion and bacterial inhibitor solution designed specifically to satisfy the requirements of NFPA 13.

TIM O’LEARY | Huguenot Laboratories

7/29/2019

MIC is caused by bacterial in combination with four other environmental conditions: Metals (host location), nutrients, water, and oxygen. (although some types of bacteria need little to no oxygen). The bacteria that cause MIC are ubiquitous in the environment and piping materials. MIC is a cause of concern in many industries such as chemical processing, oil and gas, underground pipeline, water treatment and construction trades. MIC is most prevalent in fire sprinkler systems. That’s because they are stagnate water systems. MIC in fire sprinkler systems is concentrated and accelerated by the activity of specific bacteria within a fire-sprinkler system, resulting in the premature failure of metallic system components.

The National Fire Protection Association (NFPA) has published information on dealing with MIC in Fire Sprinkler Systems and offers some consideration specific to this application.

The 2019 Edition of NFPA 13 states:

5.1.5 Water Supply Treatment
5.1.5.1 Water supplies and environmental conditions shall be evaluated for the existence of microbes and conditions that contribute to microbiologically influenced corrosion (MIC). Where conditions are found that contribute to MIC, the owner(s) shall notify the sprinkler system installer and a plan shall be developed to treat the system using one of the following methods:
(2) Treat all water that enters the system using an approved bacterial inhibitor.
(4) Install corrosion monitoring station and monitor at established intervals
.

5.1.5.2 Water supplies and environmental conditions shall be evaluated for conditions that contribute to unusual corrosive properties. Where conditions are found that contribute to unusual corrosive properties, the owner(s) shall notify the sprinkler system installer and a plan shall be developed to treat the system using one of the following methods:

(2) Treat all water that enters the system using a listed corrosion inhibitor.
(3) Implement an approved plan for monitoring the interior conditions of the pipe at established intervals and locations.



5.1.5.3 Where listed bacterial inhibitors and/or corrosion inhibitors are used, they shall be compatible with system components. Where used together, they shall be compatible with each other.

7.8 Additives and Coatings

7.8.1 Additives to the water supply intended for control of microbiological or other corrosion shall be listed for use within fire sprinkler systems.

7.8.2 Internal pipe coatings, excluding galvanizing, intended for control of microbiological or other corrosion shall be listed for use within fire sprinkler systems.