Document NNEyMd8jZqO6bZeLBNq41VbpR

REV F1 American Pacific Corp (2-BTP Clean Fire Extinguishant) Exhibit A - Additional Background on the Effort to Replace Severe Ozone Depleting Halons with 2-BTP A. Designing the Ideal Halon-like Fire Extinguishing Agents Early halon replacement research programs focused on surveying all chemical classes to determine those types of chemicals that had desirable fire suppression capabilities.1, 2, 3 Both the National Institutes of Standards and Technology (NIST) and the New Mexico Engineering Research Institute (NMERI) were leaders in examining possible fire suppressant chemicals. Independently and later together, these research organizations looked at nearly every element in the periodic table to determine which elements might hold promise as possible chemical constituents for halon replacement agents. Even before the signing of the Montreal Protocol, researchers identified at least four criteria that must be satisfied simultaneously to have a viable halon replacement candidate for critical use applications such as for aviation:4 1. Highly effective in suppressing multiple classes of fires in both indoor and outdoor environments and preventing explosions. 2. Short atmospheric lifetime to minimize the negative effects on the environment. 3. Low acute toxicity so as not to harm personnel during the fire extinguishing process. 4. Clean (gaseous or volatile) and non-conductive so as not to leave a residue on high-value assets or short circuit electronics. Obviously, any acceptable replacement candidate must also be manufacturable at a reasonable cost and be compatible with extinguisher hardware materials. When uses and applications were evaluated to fill the need for a halon-like agent, those uses and applications which do not require all four criteria typically could be replaced with a non-halon-like agents (CO2, dry-chemical, inert gases, foam, water mist, etc.). Critical uses and applications that do require all four criteria to be met simultaneously are aviation, marine (boats, ships, yachts, engine compartments, control rooms), commercial (Clean Rooms, power plants, heavy mechanical equipment, laboratories, process control rooms, transmission facilities, telecommunications facilities, utility vaults), transportation (automobiles, railroad machinery), military (computer and control rooms, flight lines, training 1 Nimitz, J. S., Tapscott, R. E., Skaggs, S. R., and Beeson, H. D., Survey of Near-Term (Group 1) Candidate Fire Extinguishing Agents, Air Force Engineering and Services Laboratory, Tyndall Air Force Base, Florida, July 1989. NMERI IH 89/100. 2 Tapscott, R. E., Lee, M. E., Moore, T. A., Moore, J. P., Nimitz, J. S., Skaggs, S. R., and Floden, J. R., Next Generation Fire Extinguishing Agent, Phase V Initiation of Halon Replacement Development, ESLTR8703, Vol. 5 of 5, Air Force Engineering and Services Laboratory, Tyndall Air Force Base, Florida, August 1989. NMERI SS 2.06(2). 3 Pitts, W. M., Nyden, M.R., Gann, R. G., Mallard, W. G., and Tsang, W. Construction of an Exploratory List of Chemicals to Initiate the Search for Halon Alternatives, NIST Tech Note 1279. Air Force Engineering and Services Laboratory, Tyndall AFB, Florida, national Institutes of Standards and Technology. Gaithersburg, Maryland, USA, August 1990. 4 Skaggs, S. R., "Second-Generation Halon Replacements," Proceedings of the Halon Alternatives Technical Working Conference, 11-13 May 1993, Albuquerque, New Mexico. REV F1 facilities), protection of some cultural or historical assets, and certain other industrial applications where electronics and precision machinery are being protected. Since the initial efforts to replace halons started in the early 1990's, halons deployed in several uses and applications have been replaced by non-halon-like agents, because there were adequate lower performance conventional alternative fire protection strategies that did not impact the life safety capabilities.5 Two common non-halon-like agents that are installed are dry chemical (in the form of monoammonium phosphate, sodium and potassium bicarbonate (Purple K, etc.) and carbon dioxide (CO2). The problem with dry chemical is that it obscures spaces where it is deployed with a cloud of powder and the deployment and byproducts typically result in corrosion of equipment protected. The NFPA Standard 10 (section 5.5.6.1) states "dry chemical fire extinguishers shall not be installed for the protection of delicate electronic equipment...dry chemical residue will probably not be able to be completely and immediately removed, and, in addition, multipurpose dry chemical exposed to temperatures in excess of 250F (121C) or relative humidity in excess of 50 percent can cause corrosion") risking critical damage.6 The problem with CO2 is that it is not rated for Class A (normal combustible) fires and given its gaseous nature, ineffective outside where even a slight wind negates its effectiveness.6 However, there are still certain uses and applications that require a clean, highly effective at suppressing fires, acutely non-toxic, environmentally friendly halon-like agent. The criteria for the ideal halon replacement (drop-in) candidate are outlined above. For years, researchers theorized what chemical characteristics were required to meet those criteria in their quest for suitable halon replacement candidates.4 The ideal halon replacement would contain either bromine or iodine to be highly effective at fire suppression and explosion prevention. Bromine and iodine interrupt the catalytic combustion chain reaction, which is much more effective than reducing the oxygen at the combustion source ("smothering" effect like with CO2 and other inert gases). A chemical containing bromine or iodine also requires some chemical feature to be present that reduces the tropospheric lifetime, so the chemical does not reach the stratosphere and contribute to ozone depletion and global warming. Chemical features known to reduce the atmospheric lifetime include the presence of unsaturated carbon bonds, polar constituents such as oxygen, and iodine atoms. Unsaturated compounds (those containing carbon to carbon double or triple bonds) are susceptible to degradation by reaction with hydroxyl free radicals in the troposphere limiting their atmospheric lifetimes. Atmospheric lifetimes of polar-substituted chemicals may be limited by water solubility, which allows the compound to be "rained out" of the atmosphere. The presence of iodine atoms allows tropospheric photolysis, reducing this chemical's atmospheric lifespan. Thus, the incorporation of any of these features limits the impact on stratospheric ozone and global warming. Given that an ideal halon replacement candidate contains bromine or iodine for highly effective fire suppression and either unsaturated carbon bonds, polar substituents, or iodine to lower the atmospheric lifetimes, the molecule must also incorporate features to limit the toxicity.4 In other words, the same characteristics that make a chemical reactive in the lower atmosphere providing limited environmental impact, also make the chemical reactive in the body, which could lead to an undesirable toxicity. Increasing the number of fluorine atoms on the molecule helps to reduce the toxic effects of the chemical. The US Department of Defense funded the Next Generation Fire Suppression Technology Program (NGP)Error! Bookmark not defined. where the goal of the program was "to develop and demonstrate by 2004, retrofittable, economically 5 Report of the Fire Suppression Technical Options Committee, Vol 1., 2022 Assessment Report, UN Environment Programme, December 2022. 6 NFPA 10 Standard for Portable Fire Extinguishers, 2018 edition, National Fire Protection Association. REV F1 feasible, environmentally acceptable, and user-safe processes, techniques, and fluids that meet the operational requirements currently satisfied by halon 1301 systems in existing weapons systems."7 This approach to new chemical screening (pg. 623) included segregation of groups.7 The groups included chemicals families that were not to be pursued further. Those chemical families included (table 7-12), brominated, chlorinated and fluorinated alkanes (already well studied), chlorinated alkenes (toxicity concerns), fluorinated alkenes (limited fire suppression efficiency), alkynes (limited fire suppression efficiency), chlorinated ethers (limited fire suppression efficiency), fluorinated alcohols (limited fire suppression efficiency, along with toxicity concerns), chlorinated aldehydes and ketones (limited fire suppression efficiency), nitrogen-containing compounds (limited fire suppression efficiency), hexavalent sulfur (limited fire suppression efficiency), iodinated ethers (toxicity concerns), chlorinated ethers (limited fire suppression efficiency), fluorinated ethers (already well studied), iodinated or chlorinated alcohols (toxicity concerns), iodinated or brominated aldehydes and ketones (toxicity concerns), halogenated (I, Br, F) aromatics (toxicity concerns), nitrates, nitrites, nitroso compounds (toxicity concerns), difluorosulfur compounds (toxicity concerns), alkali metal or alkaline earth compounds (already well studied), boron or aluminum compounds (limited suppression efficiency), and titanium, antimony, germanium or silicon containing compounds (toxicity concerns). Chemicals families that were selected for further study were listed in table 7-11(pg. 625).7 Table 7-11 Chemical Family Iodine containing alkanes and alkenes Bromine containing alkenes Iodine containing ethers Bromine containing ethers Bromine containing alcohols Fluorine containing aldehydes and ketones Nitriles Fluoro- and bromofluoroamines Sulfoxides Phosphorous containing acids and esters Phosphonitriles and Phosphorous halides Copper containing compounds Iron containing compounds Tin containing compounds Manganese containing compounds High Priority X X X X Recommendation Further Quick Look Study X X X X X X X X X X X 7 Advanced Technology for Fire Suppression in Aircraft, Final Report of the Next Generation Fire Suppression Technology Program, (US) National Institute of Standards and Technology (NIST) Special Publication 1069, Richard G. Gann Editor, US Department of Commerce, June 2007. REV F1 Research projects looked at many of the chemicals identified as requiring "Further Study." For example, NMERI investigated phosphorous nitrides8 and iodine-containing chemicals9 as halon replacement agents. In many cases, the compounds were either not volatile enough to be effective 3-dimensional agents, were not clean and electronically non-conductive, or were toxic. One class of chemicals that showed great promise was the bromofluoroalkene family (pg 662).7 Table 7-27 (pg. 663) presented candidates for three carbon compounds with 3, 4, or 5 fluorine atoms. 2-BTP is considered a bromine-containing alkene in this context. Table 7-27 Chemical Name 2-bromo-1,1,3,3,3-pentafluoropropene 3-bromo-1,1,2,3,3-pentafluoropropene 1-bromo-1,2,3,3,3-pentafluoropropene 3-bromo-1,1,3,3-tetrafluoropropene 2-bromo-1,3,3,3-tetrafluoropropene 1-bromo-1,2,3,3-tetrafluoropropene 1-bromo-1,3,3,3-tetrafluoropropene 3-bromo-1,2,3,3-tetrafluoropropene 3-bromo-1,1,2,3-tetrafluoropropene 2-bromo-1,1,3,3-tetrafluoropropene 2-bromo-3,3,3-trifluoropropene 3-bromo-1,3,3-trifluoropropene 2-bromo-3,3,3-trifluoropropene 2-bromo-1,1,3-trifluoropropene 2-bromo-1,3,3-trifluoropropene 3-bromo-1,1,2-trifluoropropene 3-bromo-1,2,3-trifluoropropene 3-bromo-1,1,3-trifluoropropene 3-bromo-2,3,3-trifluoropropene 1-bromo-2,3,3-trifluoropropene 1-bromo-1,2,3-trifluoropropene 1-bromo-1,3,3-trifluoropropene 1-bromo-2,3,3,3-tetrafluoropropene Chemical Formula CF2=CBrCF3 CF2=CFCF2Br CFBr=CFCF3 CF2=CHCF2Br CFH=CBrCF3 CFBr=CFCF2H CFBr=CFCF3 CHF=CFCF2Br CF2=CFCFHBr CF2=CBrCF2H CH2=CBrCF3 CFH=CHCBrF2 CHBr=CHCF3 CF2=CBrCFH2 CFH=CBrCF2H CF2=CFCBrH2 CFH=CFCFBrH CF2=CHCFBrH CH2=CFCF2Br CHBr=CHCHF2 CFBr=CFCFH2 CBrF=CHCHF2 CHBr=CFCF3 Cis/trans Isomers Y Y Y Y Y Y Y Y Y Y Y Y Y Advanced Agent Development Programs 8 Skaggs, S. R., Kaizerman, J., and Tapscott. R. E., "Phosphorus Nitrides As Fire Extinguishing Agents," Proceedings of the Halon Options Technical Working Conference, 10-12 May 1995, Albuquerque, New Mexico. 9 Tapscott, R. E., Skaggs, S. R., and Dierdorf, D. S., "Perfluoroalkyl Iodides and Other New Generation Halon Replacements," 208th Annual Meeting of the American Chemical Society, 21-25 August 1994, Washington, DC. REV F1 The Advanced Streaming Agent Program was established in the 1993 timeframe.10 The objectives of the program were to develop a halon 1211-equivalent, clean, environmentally safe streaming fire suppressant to replace halon 1211 used in flightlines. This started with an identification of appropriate compound families based on 1) assessment of global environmental effects, 2) assessment of toxicity, 3) assessment of synthesis and manufacturability, and 4) testing of extinguishment effectiveness. Its successor program, the Advanced Agent Working Group (AAWG),11 established with the purpose of identifying a new generation of halon substitutes, included as members, in addition to AMPAC, BP Exploration (Alaska) on behalf of the Alaska North Slope Oil & Gas Field Owners, the US Army, Navy and Air Force, the US EPA, Halon Alternatives Research Corporation, NIST, National Air and Space Administration (NASA), Dupont, UK MoD, QinetiQ (formerly UK Defence Evaluation and Research Agency), NMERI, and Kidde plc. For an extended period, the AAWG held quarterly progress meetings. NMERI led the work on the evaluation of an advanced group of chemicals that might be effective as halon substitutes. The tools used for development included both laboratory evaluations and medium and large-scale field testing.i Bench scale laboratory testing included the use of the Cup Burner Apparatus to screen candidate agents' fire suppression ability. The Cup Burner test utilizes a glass column with glass beads at the bottom where fuel (typically n-heptane) is burned in a controlled manner and agent is introduced into the column in a precise manner to measure the volume of agent necessary to extinguish the flame. These data were a good predictor of the concentration needed for a total flooding agent in an enclosed space. The data was most useful in comparing the performance of candidate agents to both halon 1211 and 1301 baselines and to other candidate agents. In 1999, NMERI provided a progress report on advanced agent development at the Halon Technical Options Working Conference.12 The key term "tropodegradable" was adopted to describe a class of candidate agents and it was pointed out that there are four primary processes for removal of organic molecules from the troposphere: 1. Reaction with atmospheric hydroxyl free radicals, 2. Photolysis, 3. Physical removal and 4. Reaction with tropospheric ozone. Hydroxyl free radicals exist in low concentrations throughout the atmosphere and are highly reactive with synthetic chemicals that might be present. Photolysis (decomposition by sunlight) occurs with only a few chemicals under study as halon substitutes. Rainout is the most common physical removal method. Tropospheric ozone, of course, plays a different role from ozone in the stratosphere (which is beneficial). 2-BTP is part of the bromofluoroalkene group that contains carbon-carbon double bonds. These molecules react rapidly with both hydroxyl free radicals and tropospheric ozone, thus, providing a short atmospheric lifetime. NMERI identified advanced agent candidates by number.12 2-BTP was accordingly assigned number 873, which was used for progress reports and by AMPAC in its early evaluations. In 1999, NMERI reported that 70 compounds had been identified and eight had been tested for acute toxicity in experimental rats for exposures of 5 minutes. Compound 873 and another compound seemed to have the most benign impact during this screening test. NMERI measured n-heptane Cup Burner performance for Compound 873 and found it was 2.55% by volume. This compared favorably to that of halon 1301 (approximately 3.0%, table 1, pg. 133). 10 Skaggs, S. R., Moore, T. A., and Dierdorf, D. S., Advanced Streaming Agent Program, Program Workplan, Wright Laboratories (WL/FIVCF), Tyndall Air Force Base, Florida and Applied Research Associates, Inc., Tyndall Air force Base, Florida, November, 1993. NMERI OC 94/12. 11 Tapscott, R. E, Heinonen, E. W., and Skaggs, S. R., "Advanced Agent Working Group," Proceedings of the Halon Options Technical Working Conference, 10-12 May 1995, Albuquerque, New Mexico. 12 Mather, J. P. and Tapscott, R. E., "Tropodegradable Halocarbons and Main Group Element Compounds," Proceedings of the Halon Options Technical Working Conference, April 21-29, 1999, Albuquerque, New Mexico. REV F1 Kidde later provided an update on advance agent development at the Halon Technical Options Working Conference in 2001.13 Kidde developed an alternate Cup Burner design where the fuel temperature was elevated. This resulted in a new set of Cup Burner data to be used for comparison purposes. Using this apparatus, the extinguishing concentration for 2-BTP was found to be higher, 4.7%, while other compounds were also measured using this device to be higher, including halon 1301 at 4.1%. The major AAWG update in 2002 summarized its work where eight candidates were evaluated.14 The paper concluded that 2 BTP "... is a drop-in replacement for halon 1211. Like halon 1211, it is a chemically acting fire extinguishant, and both agents have similar toxicological profiles. Unlike halon 1211, BTP has a significantly reduced environmental impact, by virtue of it being tropodegradable." As demonstrated above, after decades of research and testing, screening and evaluation, few chemicals have fit the halon-like replacement criteria of being electrically non-conductive, volatile enough to provide 3-dimensional coverage, environmentally low impact, acutely non-toxic, and manufacturable in quantities to serve world-wide demand for aviation and critical industrial and military uses. Only 2-BTP comes close to being an ideal halon replacement agent. There are currently no other clean fire protection agents available that won't jeopardize safety in critical applications. 13 Grigg, J., Chattaway, A., and Ural, E., "Evaluation of Advanced Agent Working Group Agents by Kidde," Proceedings of the Halon Options Technical Working Conference, April 24-26, 2001, Albuquerque, New Mexico, USA. 14 Grigg, J., Chattaway, A., "The Evaluation of Bromotrifluoropropene as a Halon 1211 Replacement," Proceedings of the Halon Technical Options Technical Working Conference, 2002, Albuquerque, New Mexico USA.