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Eco-Friendly Foam Extinguishing Agents for Class A Fires

1.

DEVELOPMENT NEEDS

Since Japan is blessed with comparatively abundant
water resources, we rely solely on water to extinguishClass A fires in buildings etc. Nations with more limited
water resources, however, in order to extinguish such fires
effectively using smaller amounts of water, have long
been engaged in research and development of water
additives such as foam extinguishing agents, consisting
mainly of surfactants. In the United States there are evenareas where virtually all fire-fighting actions involve theuse of foam extinguishing agents for Class A fires.
In recent years many countries have used extinguishingfoams for Class A fires, and Japan has gradually begun toadopt fire-fighting strategies using them. At the present
time, however, most of the foams for Class A fires available on the market are not produced domestically but areimported, mostly from Western countries.
An ecosystem risk assessment for foam extinguishing
agents carried out in 1994 by the Forest Service of theUSDA found that when direct run-off into rivers andstreams occurs, there is a high risk to aquatic life, due primarily to residues of synthetic surfactant constituents, andthat consideration must be given to preventing it entering
the water system. Similarly in Japan, the 2003 Report on
Investigation and Studies Relating to Measures against
Forest Fires from the Fire and Disaster Management
Agency and the Forestry Agency raises concerns about
the direct and indirect effects on the environment of theapplication of fire extinguishing agents.
Accordingly Furukawa Techno Material has focused its
attention not on synthetic surfactants but on soap, theconstituents of which break down readily in the naturalenvironment, and by developing a surfactant having soap
as the primary constituent, has made possible the realiza-tion of an extinguishing foam that causes less damage tothe environment. We believe that this extinguishing agent
is responsive to environmental needs, and have begun
work on product development.

2.

R&D PROGRAM

Based on these considerations, therefore, in 2001
Furukawa Techno Material, together with Shabondama
Sekken K.K., known for its manufacture of natural soaps,
and the Kita-Kyushu City Fire Department, formed a joint
development project team. In fiscal 2003, after a 2-yearbasic research period, a new member was added--KitaKyushu Municipal University, Faculty of International
Environmental Engineering--in a new project combining
private industry, academia and government, and we havebegun this R&D work anew based on the new organizational structure. Figure 2 shows the interaction of theseR&D entities.

3.

PHYSICAL PROPERTIES OF PRODUCTDEVELOPEDThe basic constituents are fatty acids extracted fromplants that Shabondama Sekken uses in its own products. The complete product developed here (hereinafterreferred to as “soap-based extinguishing agent”) has theproperties listed below, and is suitable for use for firefighters actually on the front line.
• Main constituent:
Organic surfactant (soap constituent)• Mixing ratio with water: 1%• Specific gravity:
1.137 (at 20°C)-32.5°C• Flow point:• Ignition point:
100°C or more
• Dynamic viscosity: 49 cSt (at 20°C)

Kita-Kyushu Municipal Univ.
Shabondama Sekken K.K.

Furukawa
Techno Material

Kita-Kyushu
City Fire Dept.

Study on constituents,composition andmanufacturing method
Evaluate environmental toxicity

Evaluate properties
and conditions
Fire-extinguishingexperiments
Study composition

Verify in actualﬁres

Actualadoption

Propose improvements
Verify existing problems
Propose improvements
Propose improvements

Figure 1

Spraying of water with foam during a Class A fire.

Figure 2

Organization of R&D system.

Furukawa Review, No. 32

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Eco-Friendly Foam Extinguishing Agents for Class A Fires

FIRE-EXTINGUISHING PERFORMANCE

Within Japan, where foam extinguishing agents for ClassA fires are not widely used, performance standards havenot been clearly set forth. Furukawa Techno Materials
therefore proposes an experimental model for extinguishing wood fires.
Based on repeated in-house evaluation, a small-scalemodel was adopted for the fire-extinguishing experiments,and once a clear expectation regarding the desired performance was reached, it was put into practice using theIntegrated Experimental Fire-Extinguishing Experiment
Building belonging to the National Research Institute of Fireand Disaster, an independent administrative entity, using anA-2 model of the same standard as those used during examination of the performance of fire extinguishers and using
144 pieces of wood of equivalent size (900 x 35 x 30 mm).
As a result of the experiments, as shown in Figures 3and 4, it was found that repeated spraying using water
alone did not result in extinguishment and led to damage
and collapse, whereas, in spraying with the soap-based
agent under development, the fire was substantially put
out by the third spraying. In this way it was confirmed thaton an experimental scale we could put out the fire using asmaller amount of water than with water alone. We also

1st spray

2nd spray

3rd spray

4th spray

Spraying of waterconfirmed a fire extinguishing performance equivalent tothat of existing synthetic surfactant-based foam.

5.

ENVIRONMENTAL EVALUATIONThe soap-based extinguishing agent uses natural oils as
the surfactant that is its principal constituent, and therefore aims at reducing the impact on the natural environment by increasing biodegradability.
With respect to impact on the environment, on theassumption that the liquid used in actual fire-fighting
actions will flow along the ground and through rainwaterdrains into streams and rivers and eventually into theocean, environmental toxicity evaluations on living organisms (Paramecium caudata, green paramecium, andOryzias latipes (himedaka) were carried out using tap
water, river water and brackish water (the water formed by
the mixing of river water and sea water in river estuaries).
In evaluations involving Paramecium caudata, the soapbased extinguishing agent was found, as shown in Figure
5 and Table 1, to be from 10 to 200 times lower in toxicity

12 hours of survival (% of control)

4.

140

Soap-based extinguishing agent
Commercial extinguishing agent A
Commercial extinguishing agent B
Commercial extinguishing agent C

1201008060

Paramecium caudate

40200031030100300

1000

Spraying of water with 0.5 % synthetic surfactant

Spraying of water with 1 % soap-based extinguishing agent

Figure 3

Photos comparing fire-extinguishing experiments.

12 hours of survival (% of control)

Concentration (ppm v/v)
1201008060
Green paramecium40200031030

1003001000

Concentration (ppm v/v)
900
Start of spray

Temperature (℃)

800

Figure 5Water
0.5% synthetic surfactant

1st spray

700

1% soap-based
extinguishing agent

2nd spray

600

Tests of toxicity to Paramecium caudata and green
paramecium.

3rd spray

500

Table 1

4th spray

400
300

LD50 values for Paramecium caudata and green paramecium.

5th spray

200

Tap water (boiled)100

Soap-based extinguishing agent

980~1200 ppm

1500~1800 ppm

Commercial extinguishing agent A

17 ppm17 ppmCommercial extinguishing agent B

5.8 ppm

13 ppmCommercial extinguishing agent C

23 ppm28 ppmCommercial extinguishing agent D

55 ppm56 ppmCommercial extinguishing agent E

50 ppm51 ppmFurukawa Review, No. 32

2007

00：00

1：00

2：003：00

4：00

5：00

6：00

7：00

8：00

9：00

Elapsed time (min:sec)

Figure 4

Graph comparing the temperatures at nozzle inexperiment for extinguishing wood fires.

Paramecium caudata Green paramecium73

Eco-Friendly Foam Extinguishing Agents for Class A Fires

than commercially available extinguishing agents.
In fish toxicity evaluations using Oryzias latipes (himedaka), as shown in Figure 6 and Table 2, it was confirmedthat as water flowed from a river to its estuary, its toxicity
tended to decrease. This is because the soap that is themain constituent of the soap-based agent reacts with minerals in the water (Ca, Mg, etc.) to form metallic soaps,and as a result its surfactancy decreases.

6.

VERIFICATION IN ACTUAL FIRES

In parallel with the various evaluations described above,from fiscal 2005 into 2007 ten foam fire trucks of the KitaKyushu City Fire Department were supplied with the product being developed here, and were used in fighting actual fires, allowing us to evaluate front-line performance andmake improvements in problem areas.
During this period, in addition to improving its temperature characteristics for winter and summer, etc., the firefighters who actually used the soap-based extinguishing
agent were asked about their impressions and needs toelicit its advantages. The most prominent one given was theease with which the foam dissipated. The foam of existing
synthetic surfactant-based extinguishing agents persists asmuch as half a day or more after spraying, interfering withinvestigations of the cause of the fire and resulting in thedanger of poor footing during the fire-fighting operation,and this has been presented as a real concern in fire-fight-

ing manuals from other countries. With the product developed here, on the other hand, the foam dissipates quickly,
about 30 minutes after spraying, and it was widely praisedfor this characteristic, not found in the existing products.
In addition, in fiscal 2006, a full-scale fire-fighting experiment was carried out using municipal housing scheduled
for demolition. The building used in the test was an oldstyle council flat block of quasi-fire-resistant construction(plan: two rooms plus kitchen, area: 26.9 m2) with a combustion load, including wood, tatami mats, paper slidingdoors, etc. of 35 kg/m2, and recreated an actual multi-unit
housing fire. The fire engine used was one specificallyintended as for foam fire-extinguishing agents (CAFS)
developed by Morita Corporation, a participant in thisproject since fiscal 2005.
Figure 7 shows the conditions of the fire-extinguishingexperiment.
As a result of this it was confirmed that using a 0.5 %mixture, the fire was extinguished by spraying 480 liters(approximately 17.8 l/m2). According to statistical datafrom the city of Yokohama, the amount sprayed whenextinguishing fires in medium- and high-rise buildings
using water was 309 l/m2. Comparing the data from thisexperiment, it is confirmed that the fire was extinguishedwith about 1/17th as much liquid, verifying that the soapbased extinguishing agent developed here enables fires
to be extinguished effectively with less liquid sprayed.

→←

1500

Toxicity

High

500
1000
2000
2500
3000
3500
4000
4500

Commercial extinguishing agent A
Commercial extinguishing agent B
Commercial extinguishing agent C
Commercial extinguishing agent D
Soap-based extinguishing agent
Ultrapure water

CONCLUSION

As we have seen above, close cooperation of private industry, academia and government has resulted in developmentof a fire-extinguishing agent that meets the needs of theenvironment, and has contributed to the development offire-fighting strategies that represent a radical change fromwhat went before. This fire-extinguishing agent is scheduled to go on the market in the latter part of fiscal 2007.

0Low

TLm value (50 % survival after 12 hr)

7.

Tap water

Brackish water

Hardness zero ××← Condition of use →→→Condition at discharge
to natural world

Figure 6

Graph of tests of toxicity to Oryzias latipes (himedaka).

Table 2

Tests of toxicity to Oryzias latipes (himedaka) (50 %survival level).
Tap water

TLm12

TLm24

TLm48

Soap-based extinguishing agent

400 ppm

200 ppm

200 ppm

Commercial extinguishing agent A

25 ppm25 ppm25 ppmCommercial extinguishing agent B

20 ppm20 ppm18.5 ppm

Commercial extinguishing agent C

65 ppm65 ppm65 ppmCommercial extinguishing agent D

200 ppm

200 ppm

200 ppm

Brackish water (25% sea water)

TLm12

TLm24

TLm48

Soap-based extinguishing agent

4000 ppm

1330 ppm

650 ppm

Commercial extinguishing agent A

15 ppm

7.5 ppm

7.5 ppm

Commercial extinguishing agent B

65 ppm55 ppm20 ppmCommercial extinguishing agent C

65 ppm20 ppm20 ppmCommercial extinguishing agent D

185 ppm

133 ppm

73 ppm

For more information, please contact:
Fire Prevention Products Division, Furukawa Techno
Material		 TEL: +81-463-24-9341 FAX: +81-463-24-9346		 URL: http://www.fitec.co.jp/ftm/Figure 7

Conditions of fire-extinguishing experiment.

Furukawa Review, No. 32

200774