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  recently announced plans to phase
out of the Class B aqueous film-forming foam (AFFF) business*. 3M has been a major manufacturer of
AFFF foam under the “3M” and “Light Water” brands for nearly forty years.
3M has made the decision to exit this business because of the following reasons as quoted in a
recent notice to their customers:“Extensive scientific research has shown that low levels of materials from the perfluorooctanyl chemistry (the fluorochemical used in 3M AFFF) are widespread in the environment, including living organisms, and they persist for long periods of time. Although this same research shows that the use of these products does not pose a risk to people, 3M is taking this action now because it is consistent with our longstanding corporate values and environmental principles.” As a 3M customer, you are now faced with some tough decisions. Because 3M will manufacture AFFF for existing customers until December 2000 and alcohol resistant AFFF until at least December 2001, you have the following options: Mixing of Foam Concentrates: A consideration should you choose to stock two different brands of foam is the compatibility of the two foams when mixed in storage. The National Fire Protection Association’s NFPA Standard 11, Standard for Low-Expansion Foam, 1998 Edition makes the following recommendation in Section 2.4 Concentrate Compatibility: “Different types and brands of concentrates and solutions might be incompatible and shall not be mixed in storage.” 3M makes the following statement regarding the mixing of different brands of concentrates: “If you experience a foam system discharge, we strongly urge you not to “top off ” your system with a different foam agent, unless a qualified system consultant can assure compatibility.” The United States AFFF military specification does include a compatibility requirement for all the foams meeting the specification MIL-F-24385F. Specifically it states, “The concentrates of one manufacturer shall be compatible in all proportions with concentrate furnished by other manufacturers listed on the qualified products list.” What this means is if you have a 3M mil-spec foam, you can be reasonably confident that you can mix it with another brand of mil-spec foam. However, should you have a tank that contains an alcohol resistant, aqueous film forming foam or an AFFF that is not on the military specification, you should not add another brand of foam to this tank without assurance from the foam manufacturer that the foam will be compatible. An additional consideration is whether a system containing two brands of foam mixed in storage are listed or approved. Both Underwriters Laboratory and Factory Mutual list and approve systems, not components. If any component of the systems is changed, including changing foam from one brand to two brands mixed in storage, the system may no longer be listed or approved Considering the concerns when mixing foams, if a tank containing 3M foam is low, you may need to remove the 3M foam, clean out the tank and then replace it with a different brand of concentrate. However, before adding the concentrate, you will need to verify the system components are compatible with the new concentrate. Here are some things to consider before choosing a different brand of foam concentrate: 1. Check with the foam manufacturer to verify the system materials of construction are compatible with the foam concentrate. 2. If you require your systems to be listed by Underwriters Laboratory or approved by Factory Mutual or some other independent testing organization, check with the system equipment manufacturer or the testing agency to determine what other brands of foam are listed or approved with your system. 3. Verify that the system will properly proportion the new foam correctly. Some brands of foam have distinctly different viscosity values and may require a larger or smaller proportioning orifice to deliver the correct percentage of solution. To be sure you system is proportioning accurately, you may want to run a flow test and verify the foam concentration. 4. Re-evaluate your hazard and make sure you purchase alcohol-resistant foam concentrate should you have polar solvents to protect. You will also want to purchase foam with the same nominal use-concentration as your existing system is set to proportion. 3M foam products have a shelf life of 25 years when stored in accordance with 3M recommendations and 3M has stated that “3M express warranties for the (AFFF products) will remain in effect.” In addition 3M has stated their AFFF products do not pose a risk to people. In light of these facts, your 3M-foam stock should be considered a valuable asset. The first step in planning for the future without 3M foam may be to assess your current foam stocks. NFPA 11 recommends annual testing of stored foam concentrate. Specifically, chapter 8 on maintenance of foam systems states: “At least annually, an inspection shallbe made of foam concentrates and theirtanks or storage containers for evidenceof excessive sludging or deterioration. Samples of concentrates shall be sent to the manufacturer or qualified laboratory for quality condition testing.” By having an independent laboratory test your 3M AFFF, you can obtain an unbiased assessment of your existing foam. Testing can also verify the type of type of foam you have in your tanks and help to determine whether you can or cannot mix a different brand of foam into the tank. Once you have evaluated your existing stocks, you can develop a plan to secure an effective future supply of foam. Because cost is often an overriding factor, option 2—purchase a different brand of foam in the future as your 3M stocks are consumed—may be your most likely option. This option will require your facility to stock two brands of foam at least until your 3M foam stocks are depleted. Should you choose this option and you also determine that you cannot or will not mix the two brands in storage, you will need to develop a plan to separate the two brands. You may want to consider tank labels identifying the brand of foam in each tank. When the tanks containing 3M foam are less than full, you will want to remove the foam, clean the tank and refill with the substitute brand. It should be feasible to store the 3M foam that has been removed from the tank and use it for topping off other tanks containing the same type of 3M foam. It is unfortunate that 3M, a leading supplier of AFFF foam, is discontinuing their AFFF product line. For 3M customers, it will cause additional work and planning to ensure your plants are safe. However, if you develop a conversion plan taking into account listings, approvals, foam mixing issues and systems operations, you should be able to develop a plan that will keep your systems operating effectively. For more information contact; Joan Leedy at Dyne Technologies |
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