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Fire Protection Systems

5 Posts authored by: barrychase Employee

I am frequently asked what procedures or equipment are required in order to clear the protected space for occupancy after a clean agent discharge.


NFPA 2001 (2015) does not require any specific method of verifying or restoring the tenability of the protected space after a clean agent discharge. However, the standard gives the following advice:

A. The steps and safeguards necessary to prevent injury or death to personnel in areas whose atmospheres will be made hazardous by the discharge or thermal decomposition of clean agents can include the following:

(7) Provision for the prompt discovery and rescue of persons rendered unconscious in such areas. This should be accomplished by having such areas searched immediately by trained personnel equipped with proper breathing equipment. Self-contained breathing equipment and personnel trained in its use and in rescue practices, including artificial respiration, should be readily available.

(9) Provision of means for prompt ventilation of such areas. Forced ventilation will often be necessary. Care should be taken to readily dissipate hazardous atmospheres and not merely move them to another location.


In October 2014, the Standards Council approved the development of a new technical committee and a new document on hybrid (water and inert gas) fire extinguishing systems. A call for members was issued, and an initial roster of twelve voting members was appointed in April. The new committee will hold its first meeting on Sept 29-30, 2015 in St. Louis, MO.


If you have any questions on this project, please contact me.

Recently, I have received several inquiries regarding materials used to construct and/or coat a rooftop landing pad.


NFPA does not review or approve materials, products, or designs for compliance with our standards. However, NFPA 418 Standard for Heliports, 2011 Edition, requires the rooftop landing pad surface to "be constructed of approved noncombustible, nonporous materials." [5.4.1] Because the standard requires the materials to be approved, they should be reviewed and accepted by the authority having jurisdiction prior to use or application, in order to avoid costly changes. The noncombustibility of the material(s) and/or coating(s) should be appropriately substantiated by the manufacturer and/or helipad designer. The following criteria for determining noncombustibility has been accepted by the technical committee for the 2016 edition of NFPA 418:

  1. A material that, in the form in which it is used and under the conditions anticipated, will not ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat
  2. A material that is reported as passing ASTM E136, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 Degrees C
  3. A material that is reported as complying with the pass/fail criteria of ASTM E136 when tested in accordance with the test method and procedure in ASTM E2652, Standard Test Method for Behavior of Materials in a Tube Furnace with a Cone-shaped Airflow Stabilizer, at 750 Degrees C


The Second Draft of the 2016 edition is open for NITMAM until August 21, 2015.


If you have other questions on NFPA 418, please visit the “Technical Questions” tab at

Please Note:  NFPA members and public sector officials may request a Technical Document Interpretation.  Interpretations are provided by NFPA staff on an informal basis.   If you are not a member of NFPA and would like information on the benefits of membership, please call NFPA Customer Sales at +1 800 344-3555 or visit our web site at .

The 2016 Edition of NFPA 409 Standard on Aircraft Hangars was issued by the Standards Council at their April 2015 meeting. This new edition incorporates several significant changes that impact the design of fire protection systems in new Group I and Group II aircraft hangars.


#1 - Foam System Zoning. Low-level foam systems in Group I hangars can now be divided into zones that are independently activated, based on activation of an associated sprinkler zone or automatic detection zone. Manual activation is still required to cause all zones to discharge simultaneously and to provide coverage over the entire storage and servicing area. However, automatic activation of smaller zones may limit the affected area and the consumed quantity of foam solution in the event of an isolated fire or accidental discharge.


#2 - Water Reservoirs. The standard has long required water reservoirs to be divided into equal parts, in order to ensure that at least half of the required supply is always maintained in service. This has been changed to a recommendation, because the water reservoirs for hangars are dedicated supplies that do not require redundancy in all cases.


#3 - Redundant Fire Pumps. Historically, NFPA 409 has attempted to ensure the reliability of hangar protection systems by requiring the installation of a redundant fire pump, such that the minimum water demand can be met with the largest pump out of service. This has been relaxed in recognition of the reliability of modern fire pumps that are maintained in accordance with industry standards. The 2016 edition requires a minimum of two pumps, but a redundant pump will not be required for systems that use two or more pumps to meet the minimum demand. All pumps must be of equal capacity.


#4 - Reserve Supplies of Foam Concentrate. Previous editions have required the installation of a connected reserve supply of foam concentrate with a manual means of switching between the main and reserve supplies. The reserve supply is now permitted to meet the requirements of the 2016 edition of NFPA 11 Standard for Low-, Medium-, and High-Expansion Foam. This edition of NFPA 11 does not require a connected reserve (though it is obviously permissible to provide one). Instead, the reserve supply must be either stored on-site or available within 24 hours in order to put the system back into service after operation.


To review all of the changes in the new edition of NFPA 409, see the Second Draft Report.

11-2016The 2016 edition of NFPA 11 Standard for Low-, Medium-, and High-Expansion Foam will be presented for action during the 2015 NFPA Technical Meeting, which will take place during the Conference and Expo in Chicago on June 22-25. In total, fifteen amending motions have been certified for this document.


If pursued, amending motions 11-1 through 11-14 will seek to accept public comments related to self-expanding foam systems, which are not currently addressed by NFPA 11. If the motions pass, the scope of the standard will be expanded to incorporate requirements for this new technology.


If pursued, amending motion 11-15 will seek to reject a second revision that limits the use of unprotected carbon steel pipe to wet pipe systems that are filled with foam solution or water (Second Revision No. 12). If the motion passes, the standard will return to the First Draft text, which permitted unprotected carbon steel pipe to be used for any system having outlets that are closed to the atmosphere.


For information regarding the NFPA Standards Development Process, visit