NFPA 2001

FSSA TECHNICAL BULLETIN 
No. TB-2-2007

Update on NFPA 2001 Minimum Design Concentration for Class C Fires

As announced in the FSSA News Flash on June 6, 2007, the NFPA membership supported the motion made by Dr. Mark Robin (DuPont) to keep the minimum design concentration for Class C fire hazards at 1.2 times the minimum extinguishing concentration for Class A fires.  This Class C concentration has been used in the field since the inception of NFPA 2001 in the early 1990s.  FSSA supported the motion.

After the action by the NFPA membership, the motion to keep the minimum design concentration at the current level was submitted to the NFPA 2001 technical committee for ballot per NFPA procedure.  The result of the technical committee ballot was 19 votes in favor of the motion and 10 votes against the motion.  The result of the ballot was one vote short of the required 2/3 majority for approval.  Thus the motion approved by the NFPA membership failed to gain approval of the technical committee.

The effect of this vote by the technical committee is covered in Section 4.7.1(c) of NFPA's Regulations Governing Committee Projects:

"If the Association recommended amendment is not approved by the TC and TCC , such action of the Committee shall be deemed to be a recommendation that the portion of the Report modified by the Association recommended amendment be returned to the TC; the remainder of the Report stands as recommended by the association; and any existing text to which the returned portion pertains shall stand."  

THE PRESENT 

The "bottom line" is NFPA 2001 will go forward to the NFPA Standards Council as published in the Report on Comments with the exception of Comment 2001-61a which sought to increase the minimum design concentration for Class C hazards to 1.6 times the minimum Class C extinguishing concentration.  This portion of the report goes back to the Technical Committee for reconsideration during the next revision cycle.  So for the time being, we expect the minimum design concentration specified for Class C fire hazards in NFPA 2001 to remain at the current 1.2 times Class A minimum extinguishing concentration.

(Note:  Strictly speaking, the Standards Council in issuing a standard may make modifications as they see fit — but it would be an extreme case for the council to ignore the recommendations of both the Association and Technical Committee.  Generally actions which ignore these recommendations would only be considered if an appeal were filed on a given matter.  No appeal was filed on NFPA 2001 by the 6/26/07 deadline.)

GOING FORWARD

Brad Stilwell representing Fike at the NFPA annual meeting stated, "I believe more work needs to be done to understand the issue. I am here as a Fike employee saying that we are going to do that. We think it's a benefit to the industry to further study this to get the right answer so people do understand what it takes to extinguish a Class C fire."

FSSA will continue to support the efforts of industry to define and answer the question of best protection for Class C fire hazards.  It is in the best interests of the special hazards fire protection industry and the public served by the industry to expeditiously continue testing to better define the concentrations needed for Class C fire hazards. 

For the present, when conditions permit, one should consider removing all energy sources which can augment a fire or cause re-ignition of a fire upon discharge of a clean agent system. In case of a fire in energized electrical equipment, disconnecting electric power from the equipment turns the fire into a Class A fire. 

In those cases where disconnecting electric power would cause serious consequences, it should be understood that the current 1.2 times Class A MEC design concentration, while thus far successful in handling the fires reported from the field, possibly could be insufficient to extinguish "energy augmented" combustion in some scenarios.  Industry continues moving ahead with additional research concerning design concentrations for Class C fires.

Respectfully submitted by,

Thomas Wysocki, FSSA Technical Director
Guardian Services, Inc.