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Changes in NFPA 2001 Standard for Clean Agent Fire Extinguishing Systems

NFPA has recently issued the 2012 edition of NFPA 2001 Standard for Clean Agent Fire Extinguishing Systems. This latest edition of the Standard contains several changes, some of  which impact the DuPont product line of total flooding clean fire extinguishing agents (FM-200®, FE-25™, and FE-13™). This white paper details the changes to NFPA 2001 and discusses the impact of the changes as they relate to the use of DuPont clean fire suppression agents.

Minimum Design Concentrations

The 2012 edition of NFPA 2011 introduces changes to the minimum design concentration requirements for both Class A and Class C fires.

Class A Minimum Design Concentration.  The Class A minimum design concentration (MDC) is now required to be 1.2 times the Class A minimum extinguishing concentration (MEC),  as established in accordance with UL 2166 (halocarbons) or UL 2127 (inert gases), or the heptane cup burner value, whichever is higher.

Class C Minimum Design Concentration The Class C minimum design concentration (MDC) is 1.35 times the Class A MEC, as established in accordance with UL 2166 (halocarbons) or UL 2127 (inert gases). 

Table 1 compares required minimum design concentrations for the current (2012) and previous (2008) editions of NFPA 2001.

Table 1. Comparison of Design Concentrations: NFPA 2001

2008 Edition 2012 Edition
Class A MEC Class A & Class C MDC Class A MDC Class C MDC
FM-200® 5.2–5.8 6.25–6.7 6.7 7.0
FE-25™ 6.7 8.0 8.7 9.0
FE-13™ 12.6 15.1 15.1 17.0
Novec™  1230 3.5 4.2 4.5 4.7
Inergen® 28.5 34.2 34.2 38.5
Argonite® 31.6 37.9 37.9 42.7

Q: Do the new design concentration requirements affect the safety in use of DuPont FE products in normally occupied areas?

A: No. As seen below in Table 2, the minimum design concentrations (MDC) for Class A and Class C hazard protection remains well below the maximum allowed levels. DuPont FM-200® and FE-25TM use levels are determined using the PBPK methodology. The MDC for DuPont FE-13TM is well below the cardiac sensitization NOAEL of 30% v/v.

Table 2. Comparison of Design Concentrations: NFPA 2001

Class A MDC
2012 Edition
Class C MDC
2012 Edition
Maximum
Permitted Human Exposure

Use in Normally Occupied Areas?
FM-200® 6.7 7.0 10.5% (a) Yes
FE-25™ 8.7 9.0 11.5% (a) Yes
FE-13™ 15.1 17.0 30% (b) Yes

(a) Based on PBPK methodology
(b) Based on cardiac sensitization NOAEL

 

Q:  Do the new design concentrations alter the weight effectiveness of DuPont FE products as compared to other types of clean agents?

 

A:  No.  As seen in Table 3, HFCs remain the most effective clean agents based on the weight of agent required.

Table 3. Agent Requirements: NFPA 2001 (2012 Edition)

Class A Hazards Class C Hazards
Class A MDC
2012 Edition
(% v/v)

Agent Required per 1000 ft3
(lb)
Class C MDC
2012 Edition
(% v/v)

Agent Required per 1000 ft3
(lb)
FM-200® 6.7 32.5 7.0 34.1
FE-25™ 8.7 30.0 9.0 31.2
FE-13™ 15.1 32.5 17.0 37.4
Novec™  1230 4.5 40.7 4.7 42.6
Inergen® 34.2 36.9 38.5 42.8
Argonite® 37.9 41.8 42.7 48.9

Environmental Properties

The 2012 edition of NFPA 2001 includes a list of ozone depletion potentials (ODPs) and global warming potentials (GWPs) for the agents included in the standard.  The 2012 edition also contains a revised Section 1.6, which will read (changes from the 2008 edition shown in italics):

“1.6 Environmental Factors.  When an agent is being selected to protect a hazard area, the effects of the agent on the environment shall be considered.  Selection of the appropriate fire suppression agent shall include consideration of the following items:

(1) Potential environmental effect of a fire in the protected area

(2) Potential environmental impacts, including but not limited to Ozone Depletion Potential (ODP) and Global Warming Potential (GWP), of the clean agents that could be used.”

Q:  With higher GWP values compared to other agents, should HFC agents not be used due to a large impact on climate change?

A:  Absolutely not.  The GWP value itself does NOT indicate the impact of a given molecule on climate change. The impact of HFCs in fire suppression applications on climate change is minuscule – less than 0.01% of the impact of all greenhouse gas (GHG) emissions. 

Section A.1.6 of the 2012 edition of NFPA 2001 includes the following information to clear up this common misconception:

“Global Warming Potential (GWP)

It is important to understand that the impact of a gas on climate change is a function of both the GWP of the gas and the amount of the gas emitted. For example, carbon dioxide (CO2) has one of the lowest GWP values of all GHGs (GWP=1), yet emissions of CO2 account for approximately 85% of the impact of all GHG emissions. The US EPA has employed its Vintaging Model [US EPA, Inventory of Greenhouse Gas Emissions: 1990-2007, US EPA 2009] to estimate the emissions of GHGs from various sources, and the most recent results are shown in Table A.1.6(b) and Table A.1.6(c), which indicate the relative impact of GHG emissions (Tg of CO2 equivalents) for the various GHGs (Table A.1.6(b)) and for HFCs as a function of industry (Table A.1.6(c)).

As can be seen from Table A.1.6(b) and Table A.1.6(c), the impact (in Tg of CO2 equivalents) of HFC emissions from fire suppression applications represents 100 x ( 0.7/7150.1) = 0.0098% of the total impact of all GHGs, i.e the impact of HFC emissions from fire protection applications represents less than 0.01% of the impact of all GHG emissions. Recent results from the HEEP program, which estimates the emissions of HFCs from fire suppression, are in good agreement with the results of EPA's vintaging model results for the emission of HFCs from fire suppression applications.”

Table A.1.6(B) Relative Impact of GHG Emissions


GHG 
Emissions,
Tg CO2 Equivalents
 

% of Total Impact 
CO2 5706.4 83.6
CH4 666.5 9.8
N2O 306.2 4.5
HFCs 123 1.8
PFCs 5.6 0.1
SF6 14 0.2
All GHGs 6821.8 100%

Source: Inventory of U.S. GHG Emissions & Sinks: 1990-2010 (U.S. EPA 4/15/2012)

Table A.1.6(C) Impact of HFC Emissions


Application
Emissions,
Tg CO2 Equivalents
 

% of Total Impact 
Refrigeration/Air Conditioning 97.6 79.4
Aerosol 9.3 7.6
Foam 5.4 4.4
R-22 Manufacture 8.1 6.6
Solvents 1.3 1.1
Fire Protection 0.9 0.7
Semiconductor Manufacture 0.3 0.2
Total HFC Emissions 123.0 100%

Source: Inventory of U.S. GHG Emission & Sinks: 1990-2010 (U.S. EPA 4/15/2012)

 

Conclusion

The recent changes to the NFPA 2001 Standard result in only minor changes in the Class A and Class C minimum design concentrations for the DuPont family of clean fire suppression agents. DuPont HFC-based clean agents remain the most cost effective choice in clean agent fire protection for both occupied and unoccupied areas, and continue to offer the highest efficiency on a mass basis. These properties, along with low environmental impact and safety in use, ensure the future of clean agent fire protection with the DuPont family of clean agents.