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Spring 2000 Volume 8

Feature Articles

On April 30, 1998, a fire erupted in a laundry room in a nursing home in Lamoni, Iowa. As the fire spread, resident evacuation began. This fire was later determined to be of electrical origin and not unlike many other fires investigated around the country, except for one unusual item - the total failure of the sprinkler system!

The laundry room in which the fire began was sprinkled, and the single head should have quickly controlled the fire, but it didn’t. Investigators found the fusible link had functioned, but even though the head was opened, no water passed through it. Although maintenance records were current, the system failed. Why? When investigators pulled the head they found it plugged with hardened, rust-colored, granular material. Eventually, every head in the wing of the nursing home was inspected and found to be plugged. It was finally determined that the branch line was severely corroded and partially plugged. The culprit — Microbiological Influenced Corrosion (MIC). According to Roy Marshall, State Fire Marshal of Iowa, subsequent testing of sprinkler systems in healthcare facilities revealed that one-third of all systems had some degree of MIC.

What Is MIC?
Simply put, MIC is corrosion influenced by the activities of bacteria. MIC results in the formation of deposits (nodules) and subsequent severe pitting. This can lead to blockage of pipes and rapid failure of the fire protection system piping. It has recently been recognized that MIC in such systems is a problem throughout North America, affecting many different types of materials (e.g., steel and copper) and systems (e.g., wet and dry).

The effects of MIC in fire protection systems are costly and potentially dangerous. Pinhole leaks in the pipe are one obvious indication that MIC is present. The cost of lost time and damage to products and equipment from leaks is often many times that of the necessary repairs. A terminal at the McCarran International Airport in Las Vegas, for example, was experiencing an unusually high number of pinhole leaks in its fire sprinkler system. During the course of repairing these leaks in the less than 10-year-old system, technicians noticed a significant amount of internal buildup of nodules in the system piping.

The real problem with MIC is buildup inside the piping that impacts the hydraulic characteristics of the pipe. This buildup can break off into pieces and could plug sprinkler heads. Such was the case in the nursing home fire.

Monitoring For MIC
Recent articles from the American Fire Sprinkler Association indicate that MIC can be found in a variety of U.S. regions and in different types of fire sprinkler system piping. Therefore, monitoring piping for MIC is important to your system’s integrity.

Monitoring procedures should include analysis of source water and water from several different points in the system. If possible, the inside of one or more sections of the pipe should be closely examined for nodules and bacteria. Monitoring should be done routinely since conditions can change over time.

If MIC is detected, the interior of your fire protection system must first be cleaned to remove existing deposits and other debris. Treatment with a biocide without proper cleaning will not stop existing MIC sites from continuing to corrode. After cleaning the fire protection system, water entering the system must be treated to kill microbes entering the system. Tests of the success of cleaning and treating should be done routinely.

Slay The Monster In Your System With The Expertise of EMC
If you are experiencing unexplained pinhole leaks in your fire protection system, they may be linked to MIC. Some of these systems may have piping or heads so plugged as a result of MIC they will not function. According to the Fire Marshal for the State of Iowa, commercial property owners need to be concerned that MIC can exist undetected as the current sprinkler testing requirements offer no assurance that MIC would be identified during routine maintenance.

EMC loss control professionals have been monitoring the development of enhanced and new testing, monitoring and treatment procedures to reduce the likelihood of MIC in fire protection systems. Call your EMC agent to find out more about how EMC can help slay the monster that may be lurking in your system.

Environmentally induced corrosion (rust) that affects the exterior of fire protection components can be remedied by galvanized and copper pipe and sprinklers with special coatings.

Rust which affects the inner pipe is generally not a problem (except for dry pipe systems and even then the interval for problems is 20 plus years).

MIC is different! MIC affects most alloys such as ductile iron, steel (including stainless and galvanized), and copper. The effect of MIC does vary between the different alloys with ductile iron corroding slower than steel.

p>Following the fire in Lamoni, Iowa’s Office of the State Fire Marshal and the Health Facilities Division of the Department of Inspections and Appeals recommended that annual sprinkler maintenance at health care facilities include a visual check for the presence of MIC to be performed in the following locations:

  • Near the mid-section of the riser.
  • Near the mid-section of the cross-main.
  • At not less than three random locations on the branch lines.

If MIC is discovered in these locations, additional testing must be completed to determine the problem’s severity.

That’s good advice for any type of facility!

Late last year, OSHA released its long-awaited, much-debated proposed ergonomics program standard. In announcing the proposal, Secretary of Labor Alexis Herman stated, “Work-related musculoskeletal disorders (WMSD) such as back injuries and carpal tunnel syndrome are the most prevalent, most expensive and most preventable workplace injuries in the country.”

According to OSHA, more than 647,000 Americans suffer serious injuries and illnesses due to work-related musculoskeletal disorders. WMSD account for more than 34 percent of all lost workday injuries and illnesses and cost employers $15 to $20 billion annually in direct workers’ compensation costs.

Whether OSHA’s proposal goes through as written is dependent in part on public hearings in Washington, D. C., which begin February 26, 2000. The OSHA plan is based in part on ergonomics programs that have been successful for some employers.

The OSHA program requires employers to:

  • Demonstrate management leadership of its ergonomics program.
  • Establish a way for employees to report WMSD signs and symptoms and to get prompt response.
  • Identify the “ergonomics risk” that results in WMSD hazards and eliminate or reduce those hazards to the extent feasible.
  • Provide periodic training to employees so they know about WMSD hazards and the company’s ergonomics program.
  • Make WMSD management available, at no cost to employees, whenever a covered WMSD occurs.
  • Evaluate their ergonomics program periodically to ensure it is in compliance with the OSHA standard.
  • Maintain 100 percent of “benefits” for employees on “restricted work duty” and 90 percent for those off work as a result of a WMSD. (This is more than required by workers' compensation statutes in most states.)

Although some of the elements of this plan could be easily adopted, others may be time-consuming and expensive to implement for companies.

You can review OSHA's ergonomics standard proposal at Fax your comments about the proposal to OSHA at 202-693-1648 or call 202-693-2116. Electronic comments can be made at

With the hurricane and tornado season approaching, EMC and its Project Impact partners have produced a video that provides information about constructing a safe room. Such rooms are an important element of a comprehensive storm-preparedness program. Contact Jessie Stefanski at 515-345-7383 to obtain a copy of this presentation.

The Federal Volunteer Act of 1997 provides protection for volunteers (such as firefighters, Boy Scout leaders, etc.) when acting within the scope of their duties.

What do boiler explosions, failure of aircraft components, and costly shutdown of process plants have in common? They all may be the result of stress corrosion cracking. Such problems occur with the failure of metals under the combined action of a corrosive environment and tensile stress. The tensile stress may be externally applied or internal (residual), and is often a combination of both. The corrosive environment necessary for stress corrosion cracking is specific for an alloy system, and is often not harmful in the absence of stress.

Stress corrosion cracking can occur with little or no evidence that corrosion is occurring. It may develop as fine cracks. There may be no visual indication of impending failure. Often stress corrosion cracking occurs under relatively mild corrosive conditions for the alloy involved.

Working in conjunction with Hartford Steam Boiler Inspection and Insurance Company, EMC loss control professionals can help you implement mitigation procedures to reduce the likelihood of stress corrosion cracking in your boiler system. Such actions may include lowering internal stresses below the threshold for cracking, eliminating the corrosive environment or recommending alternative materials which are more resistant to stress corrosion cracking.

Whether you suspect a problem or not, play it safe and ask your insurance agent to have EMC’s and HSB’s loss control professionals take a closer look at your boiler and machinery.

Complement your safety meeting by using EMC’s newest safety education video tapes. VHS tapes are available to EMC policyholders on a free-loan basis. Don’t overlook this resource to enhance your current training efforts.

Ask your EMC agent for EMC’s newest Audio-Visual Directory; or click here to go to our Policyholder Information & Resources page to see our online Safety Video Catalog.

Information that will be needed at the time of ordering includes: your policy number, contact name, complete mailing address, telephone number, video(s) desired, and the date needed.