1、Designation:F1129/F1129M09 Designation: F1129/F1129M 12Standard Guide forUsing Aqueous Foams to Control the Vapor Hazard fromImmiscible Volatile Liquids1This standard is issued under the fixed designation F1129/F1129M; the number immediately following the designation indicates the yearof original ad
2、option or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe vapor released by spills of volatile hazardous substances (either
3、flammable or toxic) can presenta 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 movementinto groundwater.Aqueous foam blankets have been shown to be an effecti
4、ve technique to reduce the hazard arisingfrom vapor release of volatile chemicals and to reduce the chance of accidental ignition of flammableliquids. Because they are a common tool of the fire services, they are available early in the spillresponse effort. Foams can be used to control spill vapors
5、to extend evacuation time and may offer acontrol for the life of the incident.Effective actions have been demonstrated for a wide variety of chemical classesvolatile organics,some water reactive inorganics, and certain classes of liquefied gases.The water reactive compounds and liquefied gases requi
6、re special considerations peculiar to eachchemical grouping.Although foam solutions are not considered to be dispersants, foam treatment mayenhance the penetration of water soluble materials into the ground, or transport into the groundwater,or both. Adequate information is not available to generali
7、ze on such questions.1. Scope1.1 This guide restricts itself to addressing the application of foam to water immiscible liquid and some water reactivecompounds with boiling points above 15C for vapor control or fire suppression of land spill or contained spills on water.1.2 The values stated in eithe
8、r SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.3 This stand
9、ard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For hazard statements, see Sec
10、tion 10.2. Referenced Documents2.1 ASTM Standards:2F716 Test Methods for Sorbent Performance of AbsorbentsF726 Test Method for Sorbent Performance of Adsorbents2.2 NFPA Standards:NFPA 11 Standard for Low-, Medium-, and High-Expansion Foam33. Terminology3.1 alcohol or polar solvent foamThis is one ty
11、pe of foam that is resistant to destruction by water miscible polar compounds.It is usually termed polar solvent resistant, and contains a water soluble polymer. When this polymer contacts a water miscible1This guide is under the jurisdiction of ASTM Committee F20 on Hazardous Substances and Oil Spi
12、ll Response and is the direct responsibility of Subcommittee F20.21on Initial Response Actions.Current edition approved Nov.April 1, 2009.2012. Published December 2009.April 2012. Originally approved in 1988. Last previous edition approved in 20012009 asF1129 019. DOI: 10.1520/F1129_F1129M-0912.2For
13、 referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3Available from National Fire Protection Association (NFPA), 1
14、Batterymarch Park, Quincy, MA 02169-7471, http:/www.nfpa.org.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all ch
15、anges accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
16、United States.polar fuel, it gels and forms a membrane which floats on the fuel and serves as a barrier to protect the foam from destruction bythe fuel. Polar solvent resistant foams may be either surfactant or AFFF based. They behave like a conventional foam onhydrocarbons. They may be applied by n
17、ozzle or by any other low expansion foam-making equipment on either hydrocarbons orpolar fuels. Alcohol or polar solvent resistant foams produce surface tensions in water ranging from 15 to 50 dyne/cm.3.2 aqueous film forming foam (AFFF, pronounced “A triple F”)AFFF is a mixture of fluorocarbon and
18、hydrocarbonsurfactants. It is usually used at low expansion. The very low surface tension ofAFFF solution permits the formation of an aqueousfilm on top of most hydrocarbon fuels and alcohol-compatible material is resistant to destruction by miscible or immisciblewater-reactive or strong polar compo
19、unds, or both. Because maintenance of this film requires drainage of solution from the foam,AFFF is fast draining and the foam is not persistent. The film is easily disrupted and should not be relied upon for vapor sealingunless a visible foam blanket is present. The surface tension of AFFF solution
20、s in water is 15 to 19 dyne/cm.3.3 aqueous foama mixture of water and a foaming agent.3.4 fluoroprotein foamconventional protein foam modified by the addition of fluorocarbon surfactants. Fluoroprotein foamsare similar to protein foams except that they produce foam with greater fluidity, dry chemica
21、l resistance (for clarification see NFPA11) and greater resistance to fuel pick-up. They are used only at low expansion. The surface tension of fluoroprotein foam solution(FP) is 27 to 30 dyne/cm. Film-forming fluoroprotein agents (FFFP) are being marketed with aqueous surface tensions in the 16to 1
22、7 dyne/cm range.3.5 foama mass of bubbles formed by the mechanical agitation of foam solution with air.3.6 foam expansionthe ratio of air to water in the foam. A measure of the volume of foam produced for each volume of foamsolution used.3.7 foaming agentan organic compound or mixture of compounds w
23、hich lowers the surface tension of water and imparts afoaming capability to it. Five major types of foam liquid concentrates are in general use by the fire service.3.8 high expansion foama volumetric ratio of greater than 200:1. (See foam equipment for practical ranges of expansion.)3.9 low expansio
24、n foama volumetric ratio of typically 6:1 or 12:1 but less than 20:1.3.10 medium expansion foama volumetric ratio of 20:1 to 200:1. (See foam-making equipment.)3.11 protein foama mixture of hydrolyzed animal protein with various stabilizing materials. Protein foam may be used onlyat low expansion. T
25、he surface tension of protein foam solutions in water is 40 to 50 dyne/cm. Protein foams are subject to bacterialand fungal attack and may have shelf life limitations, as well as a biological oxygen demand (BOD) in water. a mixture ofhydrolyzed animal protein with various stabilizing materials. Prot
26、ein foam may be used only at low expansion. The surface tensionof protein foam solutions in water is 40 to 50 dyne/cm. Protein foams are subject to bacterial and fungal attack which can limitshelf life. When released to the environment, they contribute to biological oxygen demand (BOD). If a biocide
27、 is included, see 9.5.3.12 surfactant foamalso known as syndet or detergent foam. These foams are based on high-foaming synthetic surface activeagents. While these foams are normally used at high expansion, they may also be applied through low expansion foam-makingdevices. Surface tensions in water
28、are in the range 23 to 30 dyne/cm.4. Significance and Use4.1 This guide is intended as a general guide to the correct use of foams. Specific decisions on when or if foam should be usedwill depend on the circumstances and conditions of each spill situation.4.2 Polar solvent resistant AFFF can be appl
29、ied to some water reactive chemicals with a medium expansion foam nozzle toextinguish a fire and to reduce toxic vapor release to the environment.5. Film Forming Foam5.1 Film forming foam develops a thin film of aqueous solution over the surface of a non-aqueous liquid chemical in responseto a surfa
30、ce tension differential. Since water is denser than many liquid organic compounds, it will normally sink through suchcompounds. Foam agents reduce the surface tension of water. If the surface tension of the foaming solution is less than that of theorganic compound, the drainage coming from the foam
31、will tend to form a water film between the foam and the organic compound.The term “film forming” has been applied basicallycustomarily to those foaming systems with low surface tensions, normallybelow 24 dyne/cm. Film forming may occur, however, whenever the ratio of surface tensions is appropriate.
32、5.2 Use of polar solvent foam on some water reactive chemical compounds, such as silanes, will reduce the amount of waterthat comes in contact with the compound-reducing toxic vapor release. Water reactive vapors are scrubbed or reacted by the foamto lessen the vapor release to the environment.6. St
33、ability6.1 Stability is used in two senses, as a foam collapse rate and as a resistance to chemicals. Foam collapse rates are measuredonly for high expansion foams. They will range from 8 to 20 in. 20 to 50 cm per h in laboratory tests, but can be higher in thefield due to sun, wind, and precipitati
34、on. Stability in contact with reactive chemicals is a property unique to each foam type.6.2 Stability of foam in contact with water reactive chemical compounds is unique to each foam type. However, the rate thatthe water drains from the foam blanket, represented by the quarter (or 25 %) drain-down t
35、ime, is thought to be the primary factorin this regard. For example, when foam is applied to a chlorosilane compound, water draining from the foam reacts with thechlorosilane chemical forming a layer of hydrolysis products on the surface. It is this layer of hydrolysis products that, when aF1129/F11
36、29M 122sufficient thickness and consistency is established, affects the fire extinguishing capability or vapor suppression, or both, byexcluding oxygen and limiting vapor evolution. However, the hydrolysis layer shall be formed relatively slowly for extinguishingcapability or suppression of vapors t
37、o take place. If the drainage rate is too fast (that is, quarter drain-down time is short), thehydrolysis reaction takes place too quickly, producing a large amount of heat, which in turn produces more vapors. In addition,the rapid reaction causes turbulence on the water reactive chemical surface, p
38、reventing the formation of a stable layer of hydrolysisproducts. If the drainage rate is too slow (that is, quarter drain-down time is too long), the hydrolysis reaction takes place tooslowly, and a stable hydrolysis layer is not established before the foam blanket dissipates.7. Foam Equipment7.1 Lo
39、w Expansion FoamSeveral types of foam-making devices are available for generating low expansion foams. Thetraditional foam nozzle consists of a tube through which a jet of foam solution is projected. Holes in the tube just downstream ofthe jet permit the aspiration of air. Various types of obstructi
40、ons are fixed in the tube to create turbulence and mix the aspiratedair with the foam solution. There are many variations in design of foam nozzles, but all produce expansion ratios in the 6:1 to 12:1range, depending on the type of foam liquid used.7.1.1 Water fog nozzles may be used to generate foa
41、m with AFFF or synthetic agents. Such foam rarely exceeds an expansionratio of 4:1. AFFF made this way has a very fast drainage and short life. Some water fog nozzles are designed for the attachmentof foam-making tubes. When the foam-making tubes are in use, the foam-making ability of the water fog
42、nozzle is essentially thesame as that of a true foam nozzle.7.1.2 Foam nozzles in smaller sizes (up to 250 g/m) 945 L/m may be used on hose lines. Larger capacity foam nozzles aremounted on monitors or turrets. Foam nozzles are available as straight stream devices, and combination straight stream an
43、d spray.Some designs permit several different patterns.7.1.3 Straight streams give the best range, but may cause the foam stream to plunge into the spill. Plunging can aggravate vaporrelease and, in the case of a fire, may reduce control and increase extinguishment times. If possible, impinge a stra
44、ightstreamsstream against an obstacle above the spill, or onto the ground in front of the spill andspill, so the foam allowed to will flowonto the spill with reduced velocity.7.2 Medium Expansion FoamProper application of medium expansion foam requires matching the foam concentrate with aneductor (i
45、n line proportioning system), and foam nozzle. The pressure drop across the eductor and the pressure delivered at thenozzle shall be set correctly in order to ensure the correct dilution of the foam concentrate and make a foam of the right expansionratio with slow water drainage. Only use Use only t
46、hose foam generation and delivery systems that are recommended by the foamconcentrate manufacturer.7.2.1 Limit the distance between the educatoreductor and the nozzle to the manufacturers recommendation. If possible, roll thefoam gently onto the spilled material. Once the area is covered, stop the f
47、oam application and allow the foam to work at forminga barrier membrane. It is best to limit use to the least amount of foam necessary to cover the spill in order to minimize the amountof water added to the spill. Reapply foam as necessary to maintain the blanket over the spilled material.7.3 High E
48、xpansion FoamHigh expansion foam generators spray the solution onto a screen or net and induce an airflow toblow the foam. Air is supplied either by aspiration in the case of handheld hose line units or by a fan in the case of larger units(see NFPA 11 for design illustrations). Air aspirating units,
49、 because of their limited air supply, produce expansions of less than350:1 and have foam capacities of less than 1000 ft3/min 28 m3/min. Larger units using water, electric, or diesel powered fanscan produce expansions up to 1000:1 and are available in sizes up to 30 000 ft3/min 85 m3/min of foam.7.3.1 Two types of water power are available, (1) water reaction motors, and (2) water turbines.7.3.1.1 Water reaction motors divert a small portion of the foaming solution to form a jet and drive a paddle wheel attached tothe fan. They are less expensive and lig
