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    Why Keep an Inadequate Fire Extinguishing System?

    By Mark Conroy


    Cooking appliances have historically been protected with pre-engineered (packaged) systems that use an extinguishing agent that chemically reacts (saponification) with cooking oil to create a thick blanket of foam to suffocate the fire and prevent the escape of combustible vapors, thereby preventing re-ignition. Other fire protection solutions involving engineered systems, alternative extinguishing agents, and elaborate enclosure just can’t compete with pre-engineered systems utilizing an extinguishing agent that has the ability to saponify when applied to the burning cooking oil.

    A little more than a dozen years ago, the fire protection industry came to the realization that the benchmark test for listing these pre-engineered systems was not rigorous enough to reflect a typical installation. The fire test standard was updated to require using fryers with vegetable oil. Dry chemical systems that passed the old test are not able to pass the new test protocol. Only wet chemical systems are able to pass the new fire tests and be listed for this application.

    Unfortunately, only part of the problem was solved. Although dry chemical systems can no longer be installed for the protection of cooking appliances and associated hood and duct systems, the listing standard does not impact existing installations. Similar to other listing standards, it only affects the listing of products.

    NFPA 101, paragraph 9.3.2 requires that existing systems be approved in order to remain in place. Specifically, it says: “Commercial Cooking Equipment. Commercial cooking equipment shall be in accordance with NFPA 96, Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations, unless such installations are approved existing installations, which shall be permitted to be continued in service.” Paragraph 9.2.3 is referenced throughout NFPA 101, and applies to existing hospitals, hotels, and restaurants.

    The problem is with existing systems and the statement “unless such installations are approved existing installations”. Since the word “approved” means “acceptable to the authority having jurisdiction”, this implies that documentation would exist that the authority has approved the existing installation.

    From the standpoint of the fire equipment distributor (FED), there is a certain liability to servicing a system that is not documented as an “approved existing installation” in accordance with NFPA 101. Most FED’s won’t assume this liability and are justified in not servicing the systems until the installation becomes an “approved existing installation”. Since NFPA 101 requires that these systems need to be “approved existing installations”, it is up to the facility owner to acquire documentation from the Authority Having Jurisdiction and provide it to the FED. If these systems can’t be serviced because they are not “approved”, the facility owner should replace them with systems that meet NFPA 101, paragraph 9.3.2. The only other option to an “approved existing installation” is one that meets NPFA 96, paragraph 10.2.3 which says “Automatic fire extinguishing systems shall comply with UL 300 or other equivalent standards and shall be installed in accordance with the requirements of the listing.”

    Allowing a dry chemical fire extinguishing system that met listing criteria and is now deemed to be inadequate is probably not the intent of the committee in establishing this requirement. Only systems that meet the currently accepted level of safety established by the listing criteria outlined in NFPA 96 paragraph 10.2.3 or equivalent should be permitted to remain in place.

    The above article is the opinion of the author and does not necessarily represent the position of a NFPA technical committee or the NFPA and may not be considered to be or relied upon as such. Mark Conroy is an engineer with Brooks Equipment Company of Charlotte, NC.


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