ASTM F1129-88(1995)e1

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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e1
Designation: F 1129 – 88 (Reapproved 1995)
Standard Guide for
Using Aqueous Foams to Control the Vapor Hazard from
Immiscible Volatile Liquids
This standard is issued under the fixed designation F 1129; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Section 11 was added editorially in September 1995.
INTRODUCTION
The vapor released by spills of volatile hazardous substances (either flammable or toxic) can present
a significant hazard to life and property in the spill area and for some measurable distance downwind.
Such spills may also cause natural resource damage by penetration into the ground or by movement
into groundwater.
Aqueous foam blankets have been shown to be an effective mechanism to mitigate the hazard
arising from vapor release of volatile chemicals and to block accidental ignition of flammable liquids.
Because they are a common tool of the fire services, they are available early in the spill response.
Foams can be used to control spill vapors to extend evacuation time and may offer a long-term control
for the life of the incident.
Effective actions have been demonstrated for a wide variety of chemical classes—volatile organics,
water reactive inorganics and certain classes of liquefied gases.
The water reactive compounds and liquefied gases require special considerations peculiar to each
chemical grouping. Although foam solutions are not considered to be dispersants, foam treatment may
enhance the penetration of water soluble materials into the ground, or transport into the groundwater,
or both. Adequate information is not available to generalize on such questions.
1. Scope 3.2 foam—a mass of bubbles formed by the mechanical
agitation of foam solution with air.
1.1 This guide restricts itself to addressing the application of
3.3 foam expansion—the ratio of air to water in the foam. A
foam to water immiscible liquid compounds with boiling
measure of the volume of foam produced for each volume of
points above 15°C for vapor control of landspill or contained
foam solution used.
spills on water.
3.4 high expansion—a ratio of greater than 100:1. (See
1.2 This standard does not purport to address all of the
Foam Equipment for practical ranges of expansion.)
safety concerns, if any, associated with its use. It is the
3.5 foaming agent—an organic compound or mixture of
responsibility of the user of this standard to establish appro-
compounds which lowers the surface tension of water and
priate safety and health practices and determine the applica-
imparts a foaming capability to it. Five major types of foam
bility of regulatory limitations prior to use. For hazard state-
liquid concentrates are in general use by the fire service.
ments, see Section 10.
3.6 protein—a mixture of hydrolyzed animal protein with
2. Referenced Documents
various stabilizing materials. Protein foam may be used only at
low expansion. The surface tension of protein foam solutions
2.1 NFPA Standards:
in water is 40 to 50 dyne/cm. Protein foams are subject to
11 Low Expansion Foam and Combined Agent Systems
bacterial and fungal attack and may have shelf life limitations.
11A Foam Systems Medium and High Expansion
3.7 surfactant—also known as syndet or detergent foam.
3. Terminology
These foams are based on high-foaming synthetic surface
active agents. While these foams are normally used at high
3.1 aqueous foam—a mixture of water and a foaming agent.
expansion, they may also be applied through low expansion
foam-making devices. Surface tensions are in the range 23 to
This guide is under the jurisdiction of ASTM Committee F-20 on Hazardous
Substances and Oil Spill Responseand is the direct responsibility of Subcommittee
30 dyne/cm.
F20.22 on Mitigation Actions.
3.8 aqueous film forming foam—also known as AFFF (A
Current edition approved Feb. 26, 1988. Published April 1988.
2 triple F). AFFF is a mixture of fluorocarbon and hydrocarbon
Available from National Fire Protection Association, Batterymarch Park,
surfactants. It is usually used at low expansion. The very low
Quincy, MA 02269.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
F 1129
surface tension of AFFF solution permits the formation of an 6. Stability
aqueous film on top of most hydrocarbon fuels. Because
6.1 Stability is used in two senses, foam collapse rate and
maintenance of this film requires drainage of solution from the
resistance to chemicals. Foam collapse rates are measured only
foam, AFFF is fast draining and the foam is not persistent. The
for high expansion foams. They will range from 8 to 20 in. (20
film is easily disrupted and should not be relied upon for vapor
to 50 cm) per h in laboratory tests, but can be higher in the field
sealing unless a visible foam blanket is present. The surface
due to sun, wind, and precipitation. Stability in contact with
tension of AFFF solutions in water is 15 to 19 dyne/cm.
reactive chemicals is a property unique to each foam type.
3.9 fluoroprotein—conventional protein foam modified by
the addition of fluorocarbon surfactants. Fluoroprotein foams
7. Foam Equipment
are similar to protein foams except that they produce foam with
7.1 Low Expansion Foam—Several types of foam-making
greater fluidity, dry chemical resistance (for clarification see
devices are available for generating low expansion foams. The
NFPA Standard 11) and greater resistance to fuel pick-up. They
traditional foam nozzle consists of a tube through which a jet
are used only at low expansion. The surface tension of
of foam solution is projected. Holes in the tube just down-
fluoroprotein foam solution (FP) is 27 to 30 dyne/cm. Film-
stream of the jet permit the aspiration of air. Various types of
forming fluoroprotein agents (FFFP) are being marketed with
obstructions are fixed in the tube to create turbulence and mix
surface tensions in the 16 to 17 dyne/cm range.
the aspirated air with the foam solution. There are many
3.10 alcohol or polar solvent—there are two types of foams
variations in design of foam nozzles, but all produce expansion
which are resistant to destruction by water miscible polar
ratios in the 6:1 to 12:1 range, depending on the type of foam
compounds. One type, (1) based on protein foam, has been
liquid used.
available for years. This type, called 88alcohol,’’ since that was
7.1.1 Water fog nozzles may be used to generate foam with
the polar compound it was usually used against, contains a
AFFF or synthetic agents. Such foam rarely exceeds an
water insoluble metal stearate. The insoluble material serves as
expansion ratio of 4:1. AFFF made this way has a very fast
a barrier between the fuel and the foam. Because the stearate
drainage and short life. Some water fog nozzles are designed
interferes with foaming, the foam liquid must be added to the
for the attachment of foam-making tubes. When the foam-
water close to the foam-making device. Alcohol type protein
making tubes are in use, the foam-making ability of the water
foam is not suitable for use on hydrocarbons nor is it effective
fog nozzle is essentially the same as that of a true foam nozzle.
if applied from a nozzle. Gentle (NFPA Type I) application is
7.1.2 Foam nozzles in smaller sizes (up to 250 g/m) (945
required, as described in NFPA Standard 11. A second type of
L/m) may be used on hose lines. Larger capacity foam nozzles
material, (2) usually termed polar solvent resistant, contains a
are mounted on monitors or turrets. Foam nozzles are available
water soluble polymer. When this polymer contacts a water
as straight stream devices, and combination straight stream and
miscible polar fuel, it gels and forms a membrane which floats
spray. Some designs permit several different patterns.
on the fuel and serves as a barrier to protect the foam from
7.1.3 Straight streams give the best range, but may cause the
destruction by the fuel. Polar solvent resistant foams may be
foam stream to plunge into the spill. Plunging can aggravate
either surfactant or AFFF based. They behave like a conven-
vapor release and, in the case of a fire, may reduce control and
tional foam on hydrocarbons. They may be applied by nozzle
increase extinguishment times. If possible, straight streams
or by any other low expansion foam-making equipment on
should be impinged against an obstacle or the ground in front
either hydrocarbons or polar fuels. Alcohol or polar solvent
of the spill and the foam allowed to flow onto the spill.
resistant foams produce surface tensions in water ranging from
7.2 High Expansion Foam—High expansion foam genera-
15 to 50 dyne/cm.
tors spray the solution onto a screen or net and induce an
4. Significance and Use airflow to blow the foam. Air is supplied either by aspiration in
the case of handheld hose line units or by a fan in the case of
4.1 It is intended as a general guide to correct use. Specific
larger units (see NFPA 11A for design illustrations). Air
decisions on when or if foam should be used will depend on the
aspirating units, because of their limited air supply, produce
circumstances and conditions of each spill situation.
expansions of less than 350:1 and have capacities of less than
3 3
5. Film Forming
1000 ft /min (28 m /min). Larger units using water, electric, or
diesel powered fans can produce expansions up to 1000:1 and
5.1 Film forming is the development of a thin film of
3 3
are available in sizes up to 30 000 ft /min (85 m /min).
aqueous solution over the surface of a nonaqueous liquid
7.2.1 Two types of water power are available, (1) water
chemical in response to a surface tension differential. Since
reaction motors, and (2) water turbines.
water is denser than many liquid organic compounds, it will
7.2.1.1 Reaction motors divert a small portion of the foam-
sink through such compounds. Foam agents reduce the surface
ing solution to form a jet and drive a paddle wheel attached to
tension of water. If the surface tension of the foaming solution
is less than that of the organic compound, the drainage coming the fan. They are less expensive and light in weight, but require
higher pressures to operate, are less efficient foam-making
from the foam will tend to form a water film between the foam
and the organic co
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