NEXT GENERATION FIRE SUPPRESSION TECHNOLOGY PROGRAM: 

FY2004 PROGRESS

Richard G. Gann 

Building and Fire Research Laboratory 

National Institute of Standards and Technology 

Gaithersburg, MD 20899 USA 

Tel: (301) 975-6866; Fax: (301) 975-3652; e-mail: rggann@nist.gov 

INTRODUCTION 

Initiated in 1997, the Department of Defense’s Next Generation Fire Suppression Technology 

Program (NGP) has completed its seventh year of research. The NGP goal is to 

“Develop and demonstrate technology for economically feasible, environmentally acceptable 

and user-safe processes, techniques, and fluids that meet the operational requirements 

currently satisfied by halon 1301 systems in aircraft.” 

Fires and explosions continue to be among the greatest threats to the safety of personnel and the 

survivability of military aircraft, ships, and land vehicles in peacetime and during combat 

operations. However, over the past six years, research to identify replacement fire suppressants 

has declined considerably, within the NGP, domestically and internationally, despite the 

continuing need. To date no commercial or military aircraft have had their halon 1301 systems 

replaced, while new systems are being installed in the cargo bays of commercial jetliners. 

Meanwhile, the international community is continuing to cast an eye on the necessity of 

maintaining the large halon 1301 reserves and even considering the requirement of a total 

phaseout. Thus, the demands on research to identify new approaches to aircraft fire suppression 

are unabated, nor have the demands on the new technologies lessened. 

NGP technology is already having an impact on aircraft fire suppression systems, and NGP 

research has generated unparalleled contributions to the published literature, all of which can be 

obtained via the NGP web site: www.bfrl.nist.gov/866/NGP. Much of the most recent progress 

is being reported at this Conference. 

TECHNICAL PROGRESS 

New Flame Suppression Chemistry

The NGP continues to examine systematically the most promising chemical families. While this 

search has produced additional knowledge of what makes a good suppressant, to date we have 

not identified a likely successor to halon 1301 for in-flight aircraft fires. The list of criteria to 

guide the search is: 

1. Fire suppression efficiency at least comparable to halon 1301 (about 3 % by volume) and

certainly higher than the hydrofluorocarbons (HFCs). Based on prior experience, this

focuses the search on compounds that contain at least one bromine, iodine or phosphorus

atom, although other possible functionalities can arise.
1

2. Short atmospheric lifetime (current preference of the order of a month), to keep ozone 

depletion potential (ODP), global warming potential (GWP) and any future unidentified 

environmental contamination issues to a minimum. 

3. Boiling point sufficiently low that for gaseous agents, an extinguishing concentration can 

be achieved within a specified time following discharge. An approximate theoretical 

upper limit is near 30 °C if the minimum temperature in flight is -40 °C. 

4. Low toxicity relative to the concentration needed for suppression. 

With regard to criterion 3, an effort is underway to improve understanding of the actual aircraft 

temperatures at which halon 1301 has been deployed. Data from incidents of halon release from 

all three services have been gathered. They document the altitude at which each release 

occurred, and we are converting this to an approximate temperature. The results will help refine 

the selection criterion for agent volatility, provide guidance to the dispersion optimization 

project, and assist platform managers in their selection of suppressant for their particular aircraft. 

A rapidly released suppressant fluid disperses partially as droplets and partially as a gas. The 

high momentum droplets can fill a volume rapidly. For halon 1301, the droplets flash vaporize, 

completing the efficient dispersion of a gaseous suppressant. Thus all of the suppressant 

contributes to the effective concentration at the fire zone. For a chemical with a higher boiling 

point and/or a higher heat of vaporization, more of the fluid reaching the fire may still be in the 

liquid phase. Larger droplets may impact and stick to cold surfaces, may not flash vaporize en 

route to the flames, and also may pass through the flames without vaporizing fully. Thus, some 

(or even much) of the agent may not contribute to the effective concentration in the fire zone. To 

compensate for this, the mass of the fire suppression system may need to be increased 

significantly, either by carrying a larger mass of agent or by heating the storage and delivery 

hardware. Thus, given knowledge of the (low) ambient temperature, it is important to be able to 

estimate the true effective concentration of a potential halon alternative. This involves droplet 

evaporation time, flame zone residence time, and saturation vapor pressure. Using the Fire 

Dynamics Simulator, we are simulating the degree of vaporization of various aerosols in a 

simulated engine nacelle and developing criteria for the physical properties that lead to an 

acceptable suppression efficiency. The input conditions for the engine nacelle reflect an 

expected range of agent deployment conditions: incoming air temperatures from 298 K to 233 K, 

nacelle interior temperatures from 298 K to 373 K, input air flow velocity of 1 m/s, mean 

suppressant drop size of ca. 20 μm, and vapor fraction immediately following release of the 

pressurized agent between 0.2 and 0.7. The results will lead to the ability to estimate the true 

effective concentration of suppressant in a two-phase dispersion. 

 

Sensitization to cardiac arrhythmia is recognized as the primary toxic effect of the halogenated 

compounds that dominate the search for halon alternatives. Estimating the cardiac sensitization 

concentration for a single compound or for a series of related compounds can have a major 

impact on whether an effective and safe alternative suppressant is identified. If a chemical is 

preferentially soluble in a barely polar liquid such as octanol, and less soluble in a polar fluid 

such as water, it may be more likely to accumulate in heart nerve and muscle cells membranes 

and cause cardiac arrhythmia. Determination of the octanol-water partition coefficient, KOW, is 

rapid and requires only a few mg of the compound. Examining the data for volatile anesthetic 
2

gases (Table 1) shows some potential for a possible correlation between KOW values and the 

occurrence of cardiac arrhythmia. 

Table 1. Anesthesia Compounds – Partitioning and Arrhythmia Properties1,2

Property Halothane Enflurane Isoflurane Desflurane Sevoflurane 

Oil-water Ratioa 220 120 170 19 55 

Arrhythmiab +++ + + ~ ~ 

a

 The "oil" phase is commonly, but not exclusively, octanol. 

b

 The symbols "+++," "+," and "~" reflect, in order, a decreasing tendency of the anesthetic to induce premature 

ventricular contractions in human patients during anesthesia. The last of these indicates only a slight tendency. 

The current phase of the examination of chemical families for potential CF3Br replacements is 

following the general guidance from the most recent assessment of the field.3 

• Last year, the NGP examined seven phosphorus-containing compounds (PCCs). Four of 

these appeared to be stable. However, despite substantial fluorination, the lowest boiling 

point (Tb) was 42 °C, and further examination of the PCCs awaits resolution of the 

boiling point criterion. 

• To determine whether there is reason to pursue the metal-containing compounds further, 

the NGP is investigating the features that lead to effective chemical action in quenching 

flame chemistry and the features that can limit the concentration of the active species in 

the flame zone. 

• Recognizing the importance of the binding energy of a suppressant to one of the free 

radicals that participate in the chain branching chemistry of flame propagation, we have 

conducted computation studies to elucidate the specific desirable values. The cases 

studies were the binding of bromine and hydrogen atoms, sodium with hydroxyl radicals 

and iron with oxygen atoms, all examined in a stoichiometric methane-air mixture. The 

binding energies were varied about the accepted values, and the resulting effect on the 

flame velocity was assessed. It was concluded that the bond energy between a catalytic 

scavenger and a flame radical must be in the range of 300 kJ/mole to 400 kJ/mole. 

The most promising remaining new chemicals are generally bromine containing for efficient 

flame quenching and fluorinated to keep boiling points low. The nitrile group (-CN) has been 

described as a "pseudohalogen," so compounds containing this functionality are being explored 

as well. In particular, members of the following families are in the process of being acquired for 

flame extinguishment testing: 

• Fluoronitiriles and bromofluoronitriles. CF3CN has a Tb of -64 oC. The flame 

extinguishment performance for this chemical and the full family is unknown, so this 

 

1

 Hemmings, H. Jr., and Hopkins, P., Foundations of Anesthesia - Basic and Clinical Sciences, Chapters 24 and 41, 

Harcourt Publishers Ltd., 2000. 

2 www.virtual-anaesthesia-textbook.com/vat/volatile.htm. 

3

 Tapscott, R.E., Sheinson, R.S., Babushok, V., Nyden, M.R., Gann, R.G., "Alternative Fire Suppressant Chemicals: 

A Research Review with Recommendations," NIST Technical Note 1443, National institute of Standards and 

Technology, Gaithersburg MD, 2001. 
3

result could open an unanticipated direction for a new candidate. CF2BrCN is expected 

to have a suppression efficiency at least comparable to halon 1301; its Tb is only 3 oC. 

The atmospheric lifetimes of the nitriles are expected to be short due to hydrolysis of the 

CN group. 

• Bromofluoropropene oxides (oxiranes). These compounds are expected to have short 

atmospheric lifetimes, but this needs to be confirmed. The lowest boiling points are 

estimated to be between 0 °C and 10 oC. 

• Bromofluoropropenes. The atmospheric lifetimes should be low since the double bond is 

reactive in the troposphere. The calculated log KOW values are near that of halon 1301 

for all possible penta-, tetra- and trifluorinated bromofluoropropenes. We are also 

seeking to obtain the three fully halogenated compounds with the lowest calculated KOW

values: CFBr=CFCF3 (Tb = 27 oC), CF2=CBrCF3 (Tb = 25 oC), and CF2=CFCF2Br. 

• Bromofluoroethers. They are expected to have relatively low toxicity and good flame 

extinguishment properties but will require some degree of hydrogenation to minimize 

ODP impact. Prime candidates are CBrF2-O-CF3, (Tb ca. -30 °C to -8 °C), CBrHF-O-CF3

and CBrF2-O-CHF2 (predicted to boil in the range 5 °C to 15 oC) and CBrF2-O-CF3. 

 

Improved Suppressant Delivery 

Prior NGP research had developed new types of solid propellant fire extinguishers (SPFE) that 

have both reduced combustion temperatures and increased flame suppression efficiency, which 

in turn will enable freedom of selection of the momentum of the suppressant stream. These have 

now been examined further. The combination of propellants based on the advanced high 

nitrogen propellant BTATZ (C4H4N14) and incorporation of coolant species into the propellant 

composition reduces exhaust temperatures by as much as 30 % vs. current baselines. The 

incorporation of potassium carbonate in the solid propellant composition decreases by up to a 

factor of three the mass of suppressant needed to extinguish mid-scale flames. Fire testing using 

hybrid fire extinguisher (HFE) configurations, in which the coolant or chemical additive is added 

downstream of the combusting propellant, showed that high-boiling agents can be delivered even 

at low temperatures, their low vapor pressures offset by the heating and pressurizing power of 

the solid propellant driven HFE. This has produced an additional ca. 30 % increase in mass 

efficiency (Figure 1). Hydrofluorocarbons and hydrofluoroethers were comparably effective on 

a mass basis. 

Tests in several military platforms were used to evaluate the effectiveness of SPFE technology. 

These test series typically included side-by-side testing of both inert and chemically active SPFE 

systems. While these test series differed in bay size, clutter, airflow, fuel flow rate and pre-burn 

conditions (and therefore fire threat), the resulting threshold successful propellant masses show a 

consistent benefit. 

These results show the validity both of the mid-scale test facility used to screen SFPE 

formulations and, more importantly, of the large improvements in efficiency from the NGPdeveloped SFPE technologies. The improved mass efficiency enables: 

• Greater flexibility in design, which can translate into a reduced number of different 
4

SPFE configurations on a given aircraft, resulting in lower per unit costs and also lower 

logistics costs; 

• Simplified existing fire protection system configuration by using a lesser number of 

different sizes of SPFEs; and 

• Opportunities to upgrade fire protection system performance without substantive 

changes to the platform.

Figure 1. Side-by-Side Testing of Inert and Chemically Active (CA) SPFEs on Sub-scale 

(FTF) and Full-Scale Military Aircraft Platforms [blue bars: inert effluent, yellow bars: 1st

generation chemically active systems; green bars: 2nd generation chemically active systems] 

NGP experiments with CF3I (Tb = -22 °C) discharges into a simulated engine nacelle at -40 oC 

have shown that inefficient dispersion should be expected when discharging a suppressant fluid 

into a system whose temperature is well below the fluid boiling point. Much of the liquid 

deposited on the nacelle floor and evaporated over many seconds. Thus, basing the design mass 

of agent for an engine nacelle on room temperature test data could lead to significant 

underestimation of the mass needed for in-flight fire suppression. Current work is directed at 

generalizing these results to a broader range of fluid boiling points and to different temperature 

differentials. The next combination will be CF2Br2 (Tb = 24.6 °C) discharged into the NIST 

nacelle simulator at room temperature and 0 °C. This compound was selected for its physical 

properties and ease of detection. 

We have completed a series of experiments to provide data regarding the behavior of suppressant 

droplets as they encounter a single well-defined cylindrical obstruction in their path. These 

results become the basis for interpreting the interactions with complex clutter and for the 
5

treatment of aerosol suppressants in suppressant flow modeling. Experiments were performed 

with water (Tb = 100 °C), HFE-7000 (Tb = 34 °C) and HFE-7100 (Tb = 61 °C). The findings 

were that: 

• As the droplets approach the upstream surface of the cylinder, they bent away and little of 

the water (< 5 %) impacted the surfaces and dripped into the collector. 

• The concentration of droplets behind the cylinder was significantly reduced from the 

upstream value. 

• Many impinging droplets rebounded off of the surface and into the free stream. As 

expected, there was no evidence of secondary breakup of the droplets. 

• Fine droplets were preferentially entrained into the recirculation region behind the 

cylinder while the larger droplets impacted the cylinder surface, accumulated and dripped 

off, and/or rebounded and dispersed radially outward into the free stream. 

• When the cylinder was heated, droplet vaporization at the surface did not result in the 

complete removal of the smaller size droplets from the distribution, but rather decreased 

the size of all droplets. 

• Droplet size increased and velocity decreased with increasing agent boiling point (Figure 

2); the differences for the two HFEs are small but real. The HFE droplets with their 

lower boiling points vaporized even before reaching the obstacle surface. 

Figure 2A. Comparison of the Droplet Mean Size for Three Agents (The flow direction is 

from right to left.) 

-120 -100 -8 0 -60 -40 -20 0 20 40 60

0

10

20

30

40

50

60

70

80

Flow

Direction

R = 20 mm

Diameter (

μm)

Streamwise Direction (mm)

 HFE7000

 HFE7100

 WATER
6

Figure 2B. Comparison of the Droplet Streamwise Velocity for Three Agents 

We have now demonstrated that VULCAN simulations are capable of reproducing observed 

behavior of a gas phase suppressant with a single clutter object. The behavior is shown in Figure 

3. Case A1 compares well with the experimental measurements of flames stabilized behind an 

obstruction in a laboratory wind tunnel (Figure 4).4

 We then investigated the effect of a second 

clutter element on the suppression of fires stabilized behind a primary clutter object. The second 

element was situated to affect the flow patterns but not directly stabilize the flame. Nonetheless, 

the aerodynamic drag on the secondary clutter can create high and low pressure regions on the 

leading and trailing sides of the clutter. For high-pressure regions located adjacent to flamestabilizing recirculation zones (Figure 4, Case A5), mixing of suppressant into the stabilization 

region is substantially enhanced, leading to reduced suppressant requirements. Conversely, if the 

low-pressure region is adjacent to the flame-stabilizing recirculation zones (Figure 4, Case A3), 

mixing of suppressant into the stabilization region is inhibited, leading to slightly greater 

suppressant requirements. 

 

4

 F. Takahashi, W. J. Schmoll, E. A. Strader, V. M. Belovich, “Suppression Behavior of Obstruction-Stabilized 

Pool Flames,” Combust. Sci. Tech. 163, 107-130 (2001). 

-12 0 -100 -80 -60 -40 -20 0 20 40 60

0

10

20

30

40

50

Flow

Direction

R = 20 mm

Streamwise Velocity (m/s)

Streamwise Direction (mm)

 HFE7000

 HFE7100

 WATER
7

Figure 3. Fires Stabilized Behind a Backward-Facing Step in a Square Wind Tunnel. [The 

hot colors represent the flame, purple is the JP-8 pool, blue is the inlet and gray represents 

the structure, less the left wall and top surface that have been removed for visibility.] 

Case A1 

Case A3 

Case A5 
8

Figure 4. Comparison of Calculated and Experimental4 Suppression Times. The 

Correlation5 is of the Experimental Values. 

VULCAN simulations are also being conducted to identify conditions for which suppression of a 

pool fire will and will not be successful in a ground-based F-18 E/F engine nacelle simulator. A 

four-nozzle design leads to good suppressant distribution (in the absence of a fire) over the 

expected range of operating conditions. In order to create conditions for which fires will not be 

suppressed, we have capped each of the nozzles in turn. Figure 5 indicates that capping nozzle 2 

has the most dramatic effect, leaving a substantial fraction of the nacelle volume with 

insufficient suppressant to extinguish a fire. The lack of suppressant is most severe along the 

lower nacelle regions where pool fires would exist. Interestingly, Figure 5 also indicates that 

capping nozzle 3 has a minimal effect on the suppressant distribution. Suppressant dispensed 

from nozzle 3 tends to overlap in space with the suppressant dispensed from other nozzles. 

Thus, the outcome of an experiment with nozzle 3 capped will be instructive. 

 

5 Hamins, A., Presser, C.;, and Melton, L., “Suppression of a Baffle-Stabilized Spray Flame by Halogenated 

Agents,” Proc. Combust. Inst. 26, 1413-1420 (1996).
9

Figure 5. Effect of Removing Distribution Nozzles on the Volume Fraction of the Nacelle 

for which the Suppressant Mass Fraction Exceeds 0.3 during Fire Extinguishment

4. Enhanced Powder Panels for Dry Bay Fire Protection 

The NGP has completed its research into enhanced powder panels with both success and high 

visibility. These aircraft fire protection devices, attached to flammable fluid containers adjacent 

to dry bays, provide passive, lightweight, effective fire protection against ballistic impact. The 

new designs have a 60 % reduction of weight (to an areal density as low as 0.136 g/cm2) and 

thickness (to as low as 1.65 mm) over our prior designs. These are 30 % lighter and 40 % 

thinner than conventional commercial panels, yet they release as much as 21 times more powder 

mass or 42 times greater percentage of total powder. Much of this was due to an innovative 

overall panel design that maximizes its front face fracture relative to commercial powder panels. 

These advanced panels were calculated to be lighter than other active dry bay fire extinguishing 

systems and current commercial powder panels for two diverse dry bay applications. 

Live fire demonstration tests of the optimized enhanced powder panels were conducted in a 0.45 

m3

 dry bay and fuel tank containing at least 49 L of JP-8. Nine tests were conducted with 12.7 

mm armor piercing incendiary projectiles fired at a velocity of approximately 757 m/s. Figure 

6A shows the commercial powder panel following a test that resulted in fire ignition, although 

the panel dislodged from the fuel tank during the impact event. Figures 6B and 6C show two 

different enhanced powder panel designs. Four of the six enhanced powder panel tests resulted 

in prevention of fire ignition. One of the other two tests resulted in the extinguishment of a fire 

0.28 s after impact; however, it was most likely caused by the ignition of a pool of residual fluid 
10

from a previous fuel tank leak. The sixth test also resulted in fire ignition, but as in the 

commercial panel test, the panel dislodged from the fuel tank due to an ineffective adhesive. 

Powder dispersion was evident throughout the dry bay following enhanced powder panel tests 

and remained dispersed for at least five minutes or more in most tests as can be seen by 

observing the left side of the "dry bay" in Figure 6D. 

Figure 6. Photographs Following Live Fire Demonstration Tests

A. Commercial Powder Panel 

B. Enhanced Design 1 

C. Enhanced Design 2 D. Enhanced Design 2 

WHAT LIES AHEAD? 

As the NGP approaches the meeting of its goal, the research will be focusing on two technical 

components: 

• Evaluating the “world of chemistry” for new flame suppression chemicals that are 

operable in aircraft dry bays and engine nacelles. It is essential that as many candidates 

as possible are identified and screened as potential halon 1301 alternatives. It is equally 
11

important that chemical families with no potential be so designated, along with the 

reasons for the designation. Thus, for other applications or should suppressant 

requirements change for fire suppression in aircraft, future investigators will have the 

benefit of the current program findings. 

• Developing principles for optimizing suppressant storage and delivery. Both research 

and engineering experimentation have shown that there is much system effectiveness to 

be gained if the suppressant is deployed efficiently and much to be lost for a delivery 

design that is incompatible with the suppressant properties. 

As these efforts near completion, a modest series of real-scale fire suppression tests will be 

conducted with the purpose of demonstrating the validity of the above findings. 

RECENT PUBLICATIONS 

New Flame Suppression Chemistry 

Shreeve, J.M., Singh, R.P., Tapscott, R.E., and Mather, J.D., "Fluoroalkyl Phosphorus 

Compounds," Final Report to SERDP, Report 2003/1/34501, New Mexico Engineering Research 

Institute, Albuquerque, NM, 2003. 

Williams, B.A., and Fleming, J.W., "Influence of Bond Energies on Catalytic Flame Inhibition: 

Implications for the Search for New Fire Suppressants," NRL/MR/6180--03-8728, Naval 

Research Laboratory, Washington DC, 2003. 

Mather, J.D., and Tapscott, R.E., "Tropodegradable and Other Environmentally Acceptable 

Flame Extinguishants," in Gann, R.G., Burgess, S.R., and Reneke, P.A., eds., Papers from 1991-

2003 Halon Options Technical Working Conferences (HOTWC), CD-ROM, NIST SP 984-1, 

National Institute of Standards and Technology, Gaithersburg, MD, 2003. 

Improved Suppressant Delivery 

Ghee, T. and Keyser, D. “Basic Aerodynamic Shapes in a Low-Speed, Highly Turbulent Flow 

Field,” AIAA 2003-3953, Am. Inst. Aero. Astro., Washington, DC, 2003. 

Presser, C., Widmann, J.F., and Papadopoulos, G., "PIV Measurements of Droplet Transport in a 

Homogeneous Turbulent Flow over a Cylinder," AIAA 2003-0846, Am. Inst. Aero. Astro., 

Washington, DC, 2003. 

Presser, C., Papadopoulos, G., and Widmann, J.F., "Droplet-Laden Homogeneous Turbulent 

Flow Past Unheated and Heated Cylinders," Proc. ASME/JSME Joint Fluids Engineering Conf. 

(FEDSM'03), FEDSM2003-45240, on CD, Am. Soc. Mech. Eng., New York, NY, 2003. 

DesJardin, P.E., Presser, C., Disimile, P.J., and Tucker, J.R.., "A Phenomenological Droplet 

Impact Model for Lagrangian Spray Transport." AIAA 2003-1322, Am. Inst. Aero. Astro., 

Washington, DC, 2003. 

Presser, C., Avedisian, C.T., and Johnson, B.S., "Phase Doppler Measurements of Liquid Agent 

Transport over a Heated Cylinder," in Gann, R.G., Burgess, S.R., and Reneke, P.A., eds., Papers 

from 1991-2003 Halon Options Technical Working Conferences (HOTWC), CD-ROM, NIST SP 

984-1, National Institute of Standards and Technology, Gaithersburg, MD, 2003. 
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Disimile, P.J., Tucker, .R., Crosswell, B., and Davis, "The Transport of Water Sprays Past 

Generic Clutter Elements Found Within Engine Nacelles" in Gann, R.G., Burgess, S.R., and 

Reneke, P.A., eds., Papers from 1991-2003 Halon Options Technical Working Conferences 

(HOTWC), CD-ROM, NIST SP 984-1, National Institute of Standards and Technology, 

Gaithersburg, MD, 2003. 

J. C. Hewson, S. R. Tieszen, W. D. Sundberg, P. E. Desjardin, "CFD Modeling of Fire 

Suppression and Its Role in Optimizing Suppressant Distribution," in Gann, R.G., Burgess, S.R., 

and Reneke, P.A., eds., Papers from 1991-2003 Halon Options Technical Working Conferences 

(HOTWC), CD-ROM, NIST SP 984-1, National Institute of Standards and Technology, 

Gaithersburg, MD, 2003. 

Presser, C., Avedisian, C.T., and Johnson, B.S., "Phase Doppler Measurements of Liquid Fire 

Suppressants over a Heated Cylinder," AIAA 2004-0479, Am. Inst. Aero. Astro., Washington, 

DC, accepted for 2004. 

Yang, J.C., Manzello, S.L., Nyden, M.R., Connaghan, M.D., “Cold Discharge of CF3I in a 

Simulated Aircraft Engine Nacelle,” Fire Safety Science – Proc. of the Seventh International 

Symposium, 715-728, (2003). 

Cyphers, D.C., Frederick, S.A., and Haas, J.P., “Demonstrating Enhanced Powder Panels,” in 

Gann, R.G., Burgess, S.R., and Reneke, P.A., eds., Papers from 1991-2003 Halon Options 

Technical Working Conferences (HOTWC), CD-ROM, NIST SP 984-1, National Institute of 

Standards and Technology, Gaithersburg, MD, 2003. 

Haas, J.P., Cyphers, D.C., and Frederick, S.A., “Enhanced Powder Panel Concepts,” Twenty 

Seventh Annual American Institute of Aeronautics and Astronautics Dayton-Cincinnati 

Aerospace Science Symposium, Dayton, OH, March 5, 2002. 

Cyphers, D.C., “Enhanced Powder Panels - Applying New Ideas to an Old Fire Extinguishing 

Method,” FS-World.com Fire & Safety Magazine, pp. 39-45, Fall 2003.