WRITTEN BY: MICHAEL G. STAG
The first firefighting foam was developed in 1902 by Russian engineer and chemist Aleksandr Loran. Loran was working in the oil and gas industry trying to find a substance to combat petroleum-based fires for which water is wholly ineffective. Loran’s solution was the first firefighting foam which was able to extinguish oil and other flammable liquids-based fires by blanketing and smothering them.
Through the years, multiple advancements were made in the firefighting foam sector. Beginning in the 1960’s, the Naval Research Laboratory (NRL) in cooperation with the 3M Company began conducting research into the use of synthetic chemicals, namely Perfluoroalkyl and polyfluoroalkyl substances (PFAS), for use in firefighting foams as a more effective means of suppressing hydrocarbon fuel-based fires. The NRL utilized 3M’s Perfluorooctanoic acid (PFOA – used to make Teflon), also known as C8, and Perfluorooctanesulfonic acid (PFOS – the main component of Scotch Guard) to develop its Aqueous Film- Forming Foam (AFFF).
AFFF are a combination of fluorocarbons, surfactants, and solubilizers. The fluorochemical based surfactant in the NRL’s AFFF reduces the surface tension of water allowing the foam to form an aqueous film on the surface of the hydrocarbon fuel that (1) suppresses vapors, (2) deprives the fuel surface of oxygen, and (3) prevents evaporation and subsequent re-ignition of the fuel.
The NRL’s AFFF quickly extinguished fuel-based fires and prevented reignition once the fire had been put out. This synthetic foam has a low viscosity allowing it to spread across the surface of flammable liquids rapidly. Once the AFFF spreads across the flammable liquid, the fluorochemical-based surfactant reduces the surface tension of water and forms an aqueous film beneath the foam on the surface of the fuel. This film cools the liquid fuel and deprives it of oxygen, stopping the formation of flammable vapors and effectively extinguishing the fire while also preventing reignition. AFFF provided nearly instant fire knockdown which greatly helped in crash rescue firefighting. The Navy received a patent on its invention in 1966 and by the mid 1960’s the 3M Company was manufacturing AFFF for the military.
By the late 1960’s, the U.S. Navy required all of its vessels to carry AFFF. In the 1970’s the Department of Defense began using AFFF to fight fuel fires at all military installations. By the late 1970’s, the Navy- developed AFFF fire suppressant was not only in heavy use by the military, but was also used at more than 90 airports in the U.S. as well as in many civilian fire departments.
While 3M was the original manufacturer of the fluorochemical-based AFFF, other manufacturers later used telomer-based fluorochemical surfactants in their AFFF. In the mid-1970s an aqueous film-forming polar foam was developed which, in addition to hydrocarbon based fires, was also used to combat fires caused by water soluble solvents such as alcohol, acetone, methyl ethyl ketone, thinners and other flammable liquids These polar foams are referred to as alcohol-resistant (AR) foams.
Class B firefighting foams are used on Class B fires involving flammable or combustible fuels. Class A foams are for use on wildfires and other Class A combustibles such as wood and paper. The development of Class A foams came about in the 1980s in response to the needs for wild forest fire control. The surfactants used in Class A foams have an affinity for carbon causing the foam/water solution to penetrate into the wood of trees and other burning combustibles with greater efficiency.
AFFF IN USE
Firefighting foams are sold as a concentrate and are typically available in 5-gallon pails, 55-gallon drums, and 275-gallon totes. The concentrate is mixed with water, either manually or through an automated system, to form a foam that is applied to blanket a fire or flammable liquid. All types of firefighting foam concentrates are combined with water at specified ratios using an in-line eductor or other mixing device. The resulting foam solution can then be fed through either a nozzle-aspirated foam system (NAFS) or a compressed air foam system (CAFS). Both systems produce a finished foam that is a combination of water, air, and foam concentrate. Varying the ratios of these three ingredients affects the physical structure of the finished foam product. Fire trucks can be equipped with reservoirs to carry both foam and water. Often trucks also contain 5-gallon buckets of AFFF for emergency use.
The military is the biggest user of firefighting foams in the U.S., comprising nearly 75% of the market according to estimates.1 The 3M Company after its initial work with the Naval Research Laboratory was the sole provider of AFFF to the military from approximately 1962 through 1982. From 1983 to 1988 both 3M and Ansul Inc. supplied the military with AFFF. The 3M Company was again the sole supplier to the military from 1989 to 2001, and Kidde National Foam has been the military supplier of AFFF since 2002.
A report estimated that municipal fire departments make up only 13% of the firefighting foam market, while petroleum-processors comprise 5% of the market.2 Other users of firefighting foam include aviation, ships, drilling platforms, and other petro-chemical manufacturers. From the 1970’s through the 2000’s the military, airports, the petrochemical industry, the oil and gas industry, and civilian fire departments were using AFFF on a regular basis. The military stockpiled millions of gallons of AFFF and it has been estimated that the average consumption was in the range of 6-12% per year.3 Thus the military alone consumed hundreds of thousands of gallons of AFFF per year.
Regrettably the rise of non-fluorinated AFFF replacements did not come to market until 2010. Furthermore, it was not until January of 2016, that the Department of Defense issued a policy requiring the Military Departments to (1) issue service-specific risk management procedures to prevent uncontrolled land-based AFFF releases during maintenance, testing, and training activities and (2) remove and properly dispose of PFOS-based AFFF from the local supplies for non-shipboard use where practical. While these
1 Moody, Cheryl A. and Field, Jennifer A. Perfluorinated Surfactants and the Environmental Implications of Their Use in Fire-Fighting Foams. Environmental Science & Technology. Vol. 34, No. 18, pp. 3864- 3870. September 2000.
2 Moody, Cheryl A. and Field, Jennifer A. Perfluorinated Surfactants and the Environmental Implications of Their Use in Fire-Fighting Foams. Environmental Science & Technology. Vol. 34, No. 18, pp. 3864- 3870. September 2000.
3 Estimated Inventory of PFOS-based Aqueous Film-Forming Foam (AFFF) by R.L. Darwin
directives were greatly welcomed, the military’s decades of use of AFFF combined with lax or nonexistent safety protocols have created an enormous burden on the environment and public health.
AFFF USE AND ENVIRONMENTAL IMPACT
AFFF made by 3M prior to 2002 generated PFOS and PFOA as a breakdown product. Manufacturers of AFFF in the United States now use PFAS other than PFOS; however, existing stocks of PFOS-based AFFF remain in use. As noted above, PFOS and PFOA are part of a larger group of chemicals called per- and polyfluoroalkyl substances (PFAS). PFOS and PFOA are the most widely studied of the PFAS chemicals because they are the two PFAS that have been produced in the largest amounts within the United States.4 PFOS and PFOA are human-made compounds that do not occur naturally in the environment.
PFOS and PFOA are extremely persistent in the environment and resistant to typical environmental degradation processes primarily because the chemical bond between the carbon and fluorine atoms is extremely strong and stable. This persistence has earned these synthetic substances the nickname “forever chemicals”. Not long after introducing these “forever chemicals” into regular use, the military and scientists within the 3M Company began to question the environmental impacts of AFFF.
In 1974, a Navy report asked whether AFFF alternatives ought to be considered for “environmental impact” reasons. One year later, 3M scientists were made aware that PFAS chemicals were bioaccumulating in the bodies of US citizens across the nation. In 1976, Navy scientists again proposed exploring alternatives to AFFF, citing environmental concerns. For more than five decades, PFAS have contaminated drinking water sources in the U.S. and around the world, presenting massive risks to public health. Studies have found PFOS and PFOA in the blood samples of the general human population and wildlife, indicating that exposure to the chemicals is widespread.5
Higher blood levels have been found in community residents where local water supplies have been contaminated by PFOA. People exposed to PFOA in the workplace are also likely to have PFOA in blood serum at levels many times higher than the general public. Furthermore, the wide distribution of PFAS in organisms is strongly suggestive of the potential for bioaccumulation and/or bioconcentration.6
In 1978, another Navy report again identified environmental and public health risks posed by AFFF and noted the “difficulties obtaining adequate information” from 3M.7 At this point when the US Navy was questioning the health and environmental impacts of AFFF, 3M was finding PFAS chemicals at levels 1,000
4 US Department of Health and Human Services – Agency for Toxic Substances and Disease Registry. 2018. “Draft Toxicological Profile for Perfluoroalkyls”; European Food Safety Authority (EFSA). 2008.
“Perfluorooctane Sulfonate (PFOS), Perfluorooctanoic Acid (PFOA) and Their Salts.” The EFSA Journal. Volume 653. Pages 1 to 131.4 US Department of Health and Human Services – Agency for Toxic Substances and Disease Registry. 2018. “Draft Toxicological Profile for Perfluoroalkyls”; European Food Safety Authority (EFSA). 2008.
5US Department of Health and Human Services – Agency for Toxic Substances and Disease Registry. 2018. “Draft Toxicological Profile for Perfluoroalkyls”; EPA 2015, “Long-Chain Perfluoroalkyl Carboxylate and Perfluoroalkyl Sulfonate Chemical Substances; Significant New Use Rule.” Proposed Rule. 40 CFR 721. Federal Register: Volume 80 (No. 13).
6 EPA 2015, “Long-Chain Perfluoroalkyl Carboxylate and Perfluoroalkyl Sulfonate Chemical Substances;
Significant New Use Rule.” Proposed Rule. 40 CFR 721. Federal Register: Volume 80 (No. 13); United Nations Environment Programme (UNEP). 2006. “Risk Profile on Perfluorooctane Sulfonate.” Stockholm Convention on Persistent Organic Pollutants Review Committee. Geneva, 6 -10 November 2006
7 Department of the Navy, “Candidate Environmental Impact Statement – Discharging Aqueous Film- Forming Foam (AFFF) to Harbor Waters During Tests of Machinery Space Fire-Fighting Foam Systems Aboard U.S. Navy Ships” (1978)
times normal in the blood of its workers and in the flesh of fish surrounding its manufacturing plants.8 Despite the fact that 3M concluded that PFOA and PFOS “should be regarded as toxic,” 3M determined that the “risks should not be reported at this time.”
Additional animal studies conducted by 3M in 1978 and 1979 further confirmed the public health and environmental risks posed by PFOS and PFOA. It is not clear whether 3M disclosed these identified risks to the Navy or others, notwithstanding increasing contamination of blood levels and cancer rates among 3M workers.
By the very early 1980’s, the Department of Defense began investigating the environmental and health impacts of AFFF through their own animal studies. A 1981 study conducted by the Air Force found AFFF harmful to female rats and their pups, including low birth weights. Air Force Animal studies by the Air Force and Navy in 1983 and 1985 found that PFAS could damage cell growth.9
The Air Force identified firefighting foam as the suspected cause of animal and vegetation deaths near Peterson Air Force Base in 1991. As a result, the Air Force implemented policies to sequester AFFF at Peterson AFB. At the same time, the Army Corps of Engineers ordered the Fort Carson Army installation to replace the use of “hazardous” AFFF with “nonhazardous substitutes.” Five years later, the Navy started more seriously exploring non-fluorinated alternatives to AFFF. At this time the Army also began requiring soldiers to treat AFFF as a hazardous waste.
Despite the substantial evidence that AFFF was an environmental and public health threat for decades, it was not until 2000 that the EPA announced that “(f)ollowing negotiations between EPA and 3M, the company…announced that it will voluntarily phase out and find substitutes for PFOS”.10 Along with the announcement of the phase out of PFOS, it was revealed that a 3M animal study revealed significant health risks associated with PFOS exposure even at low doses. Following the announcement of the phaseout in 2000, the Department of Defense held a meeting at the Naval Research Laboratory to discuss AFFF environmental issues within the Department.11
In 2001, a Department of Defense memorandum by Curtis Bowling, the Assistant Deputy Under Secretary of Defense Force Protection, noted that PFOS was “persistent, bioaccumulating, and toxic.” More than a decade later, to prevent future releases to the environment, the DOD finally stopped land-based use of AFFF in training, testing and maintenance through a department wide policy issued in January 2016. The US Navy announced that it intended to remove, dispose, and replace legacy AFFF containing PFOS and/or PFOA once an environmentally suitable substitute is identified and certified to meet milspec requirements.
In 2017, the Army completed its PFOS/PFOA water sampling at 2,905 Army locations including 380 Army drinking water systems, both inside and outside the United States. At the same time, the U.S. Air Force
8 As evidenced by documents produced by 3M in previously filed litigation.
9 S.M. Salazar, “Toxicity of Aqueous Film-Forming Foams to Marine Organisms: Literature Review and Biological Assessment” Naval Ocean Systems Center (1985)8 As evidenced by documents produced by 3M in previously filed litigation.
10 EPA News Release, “EPA and 3M ANNOUNCE PHASE OUT OF PFOS” (2000) found at https://archive.epa.gov/epapages/newsroom_archive/newsreleases/33aa946e6cb11f35852568e1005246 b4.html
11 See “Minutes of the DOD AFFF Environmental Meeting” held at the Naval Research Laboratory Navy Technology Center for Safety and Survivability Washington, D.C. On 2-3 August 2000.
completed enterprise-wide sampling of drinking water at all installations — stateside and overseas — to ensure drinking water supplies meet EPA guidelines. In 2019, the U.S Navy began investigating PFAS contamination by sampling wells around its bases.
In 2019, the Department of Defense announced a PFAS Task Force to deal with the rising problem of PFAS contamination at military installations across the country and overseas. The DOD identified 401 active and former installations in the U.S. where there appeared to be some level of PFOS/PFOA from defense activities. In addition to these installations, as of 2014, there were 664 current or former military fire- or crash-training sites, all of which are likely contaminated with PFAS chemicals.
To address the growing problems associated with the use of AFFF by fire fighters and PFAS contamination of groundwater, the U.S. Congress included a number of provisions in the fiscal 2020 National Defense Authorization Act to restrict PFAS use by the defense departments and prohibit the use of firefighting foams that contain PFAS in training. The law also requires the Department of Defense to begin testing the blood of military firefighters to determine the extent of their PFAS exposure.