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Simple Summary Compressed air, detergent, and water make up compressed air foam. Our laboratory has previously reported that compressed air foam may be an effective method for mass depopulation of caged layer hens. Gases, such as carbon dioxide and nitrogen, have also been used for poultry euthanasia and depopulation. The objective of this study was to produce compressed air foam infused with carbon dioxide or nitrogen to compare its efficacy against foam with air and gas inhalation methods (carbon dioxide or nitrogen) for depopulation of caged laying hens. The study showed that a carbon dioxide-air mixture or 100% nitrogen can replace air to make compressed air foam. However, the foam with carbon dioxide had poor foam quality compared to the foam with air or nitrogen. The physiological stress response of hens subjected to foam treatments with and without gas infusion did not differ significantly. Hens exposed to foam with nitrogen died earlier as compared to methods such as foam with air and carbon dioxide. The authors conclude that infusion of nitrogen into compressed air foam results in better foam quality and shortened time to death as compared to the addition of carbon dioxide. Abstract Depopulation of infected poultry flocks is a key strategy to control and contain reportable diseases. Water-based foam, carbon dioxide inhalation, and ventilation shutdown are depopulation methods available to the poultry industry. Unfortunately, these methods have limited usage in caged layer hen operations. Personnel safety and welfare of birds are equally important factors to consider during emergency depopulation procedures. We have previously reported that compressed air foam (CAF) is an alternative method for depopulation of caged layer hens. We hypothesized that infusion of gases, such as carbon dioxide (CO2) and nitrogen (N2), into the CAF would reduce physiological stress and shorten time to cessation of movement. The study had six treatments, namely a negative control, CO2 inhalation, N2 inhalation, CAF with air (CAF Air), CAF with 50% CO2 (CAF CO2), and CAF with 100% N2 (CAF N2). Four spent hens were randomly assigned to one of these treatments on each of the eight replication days. A total of 192 spent hens were used in this study. Serum corticosterone and serotonin levels were measured and compared between treatments. Time to cessation of movement of spent hens was determined using accelerometers. The addition of CO2 in CAF significantly reduced the foam quality while the addition of N2 did not. The corticosterone and serotonin levels of spent hens subjected to foam (CAF, CAF CO2, CAF N2) and gas inhalation (CO2, N2) treatments did not differ significantly. The time to cessation of movement of spent hens in the CAF N2 treatment was significantly shorter than CAF and CAF CO2 treatments but longer than the gas inhalation treatments. These data suggest that the addition of N2 is advantageous in terms of shortening time to death and improved foam quality as compared to the CAF CO2 treatment.

Simple Summary Reportable diseases, such as avian influenza, spread rapidly among poultry, resulting in the death of a large number of birds. Once such a disease has been diagnosed at a farm, infected and susceptible birds are rapidly killed to prevent the spread of the disease. The methods to eliminate infected caged laying hens are limited. An experiment was conducted to study the effectiveness of foam made from compressed air, water, and soap to kill laying hens in cages. The study found that stress levels of the hens killed using compressed air foam in cages to be similar to the hens killed by carbon dioxide or the negative control. Hens exposed to carbon dioxide died earlier as compared to the foam methods. The authors conclude that application of compressed air foam in cages is an alternative to methods such as gas inhalation and ventilation shutdown to rapidly and humanely kill laying hens during epidemics. Abstract During the 2014–2015 US highly pathogenic avian influenza (HPAI) outbreak, 50.4 million commercial layers and turkeys were affected, resulting in economic losses of $3.3 billion. Rapid depopulation of infected poultry is vital to contain and eradicate reportable diseases like HPAI. The hypothesis of the experiment was that a compressed air foam (CAF) system may be used as an alternative to carbon dioxide (CO2) inhalation for depopulating caged layer hens. The objective of this study was to evaluate corticosterone (CORT) and time to cessation of movement (COM) of hens subjected to CAF, CO2 inhalation, and negative control (NEG) treatments. In Experiment 1, two independent trials were conducted using young and spent hens. Experiment 1 consisted of five treatments: NEG, CO2 added to a chamber, a CO2 pre-charged chamber, CAF in cages, and CAF in a chamber. In Experiment 2, only spent hens were randomly assigned to three treatments: CAF in cages, CO2 added to a chamber, and aspirated foam. Serum CORT levels of young hens were not significantly different among the CAF in cages, CAF in a chamber, NEG control, and CO2 inhalation treatments. However, spent hens subjected to the CAF in a chamber had significantly higher CORT levels than birds in the rest of the treatments. Times to COM of spent hens subjected to CAF in cages and aspirated foam were significantly greater than of birds exposed to the CO2 in a chamber treatment. These data suggest that applying CAF in cages is a viable alternative for layer hen depopulation during a reportable disease outbreak.

This article in view of the realistic requirement of fixed fire extinguishing system in the places of water-insoluble liquid, establishes stationary compressed air foam experiment platform in combination with the advantage of compressed air foam technology. Key component nozzle and mixing chamber of the system is designed. By cold spray test, obtains parameters of gas-liquid flow、pressure, foam mixing ratio which result in different types of foam. The division of different types of foam basis is put forward, and take drainage time as indicators, get the most stable foam parameter combination; by extinguishing experiment, get the better combination of dry foam and small nozzle whose extinguishing effect is best. The results can be guidance for production research of integrated compressed air foam and system application in combustible liquid places.

In this article, based on simplifying of extinction agent's extinguishing mechanism and the fuel's combustion characteristic, an extinguishing model is established. Three kinds of fuels - 93 # gasoline, 0 # diesel oil, 95% ethanol, are applied. The compressed air Aqueous film forming foams (AFFF) is used as the extinction agent, The heat release rate of the fuels is obtained by the free burning test, the extinguishing time under different effective extinguishing intensity is obtained by the implementing actual extinguishing test. Investigation is implemented on extinguishing models of compressed air AFFF for diesel oil/gasoline extinguishing and insoluble AFFF for ethanol extinguishing, therefore the calculation method for the fire extinguishing models of different extinction agent for different fuels is obtained.

The rescue service in Luleå took an initiative in 2014 and completed a try-out with CAF-system and A-foam against a liquid fire of kerosene. The use of the CAF system against liquid fires is in great interest because increased use of A-foam could lower the use of film-forming foams that contain harmful fluorinated substances. This would lead to positive effects on the environment.The try-out in 2014 was successful and indicated that CAF-system with A-foam was a good extinguisher. Luleå rescue service began planning more large-scale try-outs, this time against gasoline fires and this study is part of that project. The aim of this study has been to get an idea of the extinguishing capacity of CAF-system and A-Foam. A literature search showed that no tests similar to those envisaged in this project were documented. The empirical study consisted of 12 small- and 2 large-scale experiments. The liquid that were used in the experiment were gasoline. The small-scale experiment followed the SP-Method 2580 and the large-scale experiment where conducted in a 60 m2 large pit. A summary of the small-scale experiment shows that no control over the fire was obtained when the foam was applied by a direct deposition technique. The foam strikes in to the fuel too hard and the blanket of foam broke down faster than new foam was applied. It required a soft deposition technique to control the fire at the small-scale experiment. The first large-scale experiment failed when no correct foam quality was obtained during the try-out. The second try-out started with the use of a traditionally CAF nozzle, which produces wet heavy foam, and no control of the fire was obtained. The foam equipment had to be changed to a medium expansion nozzle before the fire could be controlled. With the medium expansion nozzle the fire was extinguished in about 5 minutes. More expanded foam, which results in smoother application, was needed to control the fire at the large-scale experiment. The application technique is important when extinguishing fires with CAF-system and A-foam. During both the small-scale experiment as well as the large-scale experiment re-ignition attempts were conducted. These re-ignition attempts indicated that A-foam has poor fire resistance. The foam blanket quickly broke down and the fire developed to full power again shortly after being exposed to an open flame. The conclusion of the study is that a CAF system and A-foam is capable of extinguish a petrol fire of about 60 m2 with a medium expansion nozzle and an application rate of about 2.8 l / (m2 ∙ min). Validerat; 20150924 (global_studentproject_submitter)

This paper describes a newly-developed compressed-air foam (CAF) system, based on an overhead fixed-pipe installation, and presents results showing its fire suppression performance. The CAF system generates foams by injecting compressed air into the flowing foam solution. The resulting foam is characterized by excellent fire-mitigation properties. This is because compressed-air foams, at the expansion ratios of between 1:4 to 1:10, consist of very small and uniform-in-size air bubbles. The system needs little water to operate and is able to provide effective protection against Class A and B fires. The system's performance was compared to the performance of water mist and sprinkler-based installations. The experiments confirmed that the CAF system is effective in suppressing Class A and B fires. For the scenarios evaluated, the compressed-air system generated foams with sufficient momentum to penetrate the fire plume and to reach the fuel surface. The experimental results indicate that, in an open space, the foam system performs much better than water mist in extinguishing wood crib and flammable liquid pool fires. In an enclosed space, both water mist and compressed-air foam perform equally well against flammable liquid fires. The suppression performance of the CAF system on large wood crib fires was much better than a sprinkler system.

Power transformers deal with high voltage electric power and there is always a possibility of fire incidents. Because of the fire risks and the important role power transformers play in supplying electricity to the community, they must have a proper fire protection system in place., Aussi disponible en français: Protection des transformateurs électriques

Les transformateurs d'alimentation utilisent un courant électrique de haute tension, et ces appareils présentent toujours des risques d'incendie. En raison de ces risques et du rôle important que jouent les transformateurs dans la distribution de l'électricité aux collectivités, il est essentiel de prévoir avec ces appareils un système de protection incendie approprié., Also available in English: Protecting power transformers

Many halocarbon products have been introduced in the market place to fill the gap in the fire suppression area left by halons. Novec1230, which has zero ozone depletion potential, a very short atmospheric-life-time and a global warming potential of one, is one of those halocarbon products., Fire Suppression and Detection: A Technical Working Conference: 16-19 February 2010, Orlando, Florida

This paper describes the test facility and results for a fixed-pipe compressed-air-foam (CAF) system featuring an innovative air injection method and foam distribution nozzles. A prototype system was used to access whether a CAF system could meet fire safety requirements and compared its performance to that of a foam-water sprinkler system typically used in hangars. The experimental procedure used was similar to the test requirement listed in the UL162 standard., Hazardous Areas Conference 2009: 17 June 2009, Calgary, AB

Mobile compressed air-foam (CAF) is a new fire suppression system that can produce superior quality foam with high momentum. NRC undertook studies to evaluate the effectiveness of mobile CAF systems. Several full-scale compartment fire tests were conducted to compare the fire suppression performance of a manually-applied CAF system with that of hose stream applications using water alone and using water-foam solutions., Suppression and Detection Symposium (SUPDET) 2009: 01 February 2009, Orlando, FL.

This paper describes the test facility and results for a fixed-pipe compressed-air-foam (CAF) system featuring an innovative air injection method and foam distribution nozzles. A prototype system was used to access whether a CAF system could meet fire safety requirements and compared its performance to that of a foam-water sprinkler system typically used in hangars. The experimental procedure used was similar to the test requirement listed in the UL162 standard., 2008 Fire Suppression and Detection Research Applications - A Technical Working Conferernce (SUPDET 2008), March 11, 2008, Orlando, FL.

The National Research Council of Canada (NRC) has developed a means of producing Compressed-Air-Foam (CAF) in a fixed pipe system. This system provides superior quality foam with uniform distribution and high momentum. In previous studies, NRC has proven by full-scale tests that CAF has superior fire suppression performance compared to current foam or sprinkler systems. Recently, a study was carried out to develop a CAF distribution system and to evaluate the fire suppression capability of the CAF system for the protection of power transformers. This paper describes the experimental facility, including the power transformer mock-up and instrumentation, and presents experimental results of the fire suppression capability of the CAF system for power transformer protection., 7th AOSFST Symposium: 1 September 2007, Hong Kong

Power transformers play an important role in making communities function by distributing the power. Power transformers deal with high voltage electric power and there is a strong possibility of accidental fire incidents in the power transformer. Because of the high possibility of fire occurrence and the important role they play in the maintenance of normal life in the community, the power transformers must have a proper fire protection system in place to provide the best fire protection., 2006 Fire Suppression and Detection Research Application Symposium: 01 February 2006, Orlando, FL., U.S.A.

Compressed-air foam (CAF) has been proven to be an effective fire suppression material for both class A and B fires. Comparison testing between CAF and standard foam water sprinklers had been conducted previously to quantify the amount of CAF required to outperform a foam water sprinkler system in extinguishing a liquid fuel pan fire and provide superior burn-back protection as specified in the UL162 Foam Equipment and Liquid Concentrates standard. Concerns about variations in the delivered CAF density due to fluctuating water supply pressures and its performance on actual spill fires have been raised in the industry. This paper describes a series of full-scale Class B fire tests designed to address these concerns. Tests were conducted, using the fire test method described in the UL162 Foam Equipment and Liquid Concentrates standard, to establish minimum and maximum delivered densities of CAF by varying the water supply pressures. A safety factor could then be associated with the normal design application density. Tests were also conducted on a 6 m by 6 m poured concrete slab to compare CAF and standard foam water sprinklers in extinguishing free flowing heptane spill fires with and without shielded areas. These fires ranged in size from 4.65 m2 to 13 m2., Symposium on Advances in Fire Suppression Technologies, October 1, 2005, San Diego, CA.

Aussi disponible en français: La mousse à air comprimé: un succès de commercialisation de l'IRC

Compressed-air foam (CAF) has been proven to be an effective fire suppression material for both class A and B fires. Comparison testing between CAF and standard foam water sprinklers had been conducted previously to quantify the amount of CAF required to outperform a foam water sprinkler system in extinguishing a liquid fuel pan fire and provide superior burn-back protection as specified in UL162 'Foam Equipment and Liquid Concentrates'. Concerns about variations in the delivered CAF density due to fluctuating water supply pressures have been raised in the industry. This paper describes a series of full-scale Class B fire tests designed to establish minimum and maximum delivered densities of CAF by varying the water supply pressures. A safety factor could then be associated with normal design application density., Il a été prouvé que la mousse sous pression (MSP) est un agent d'extinction efficace pour les feux tant de classe A que de classe B. Des tests de comparaison entre la MSP et les gicleurs mousse-eau standard avait été réalisés auparavant afin de quantifier la mousse requise pour éteindre un feu de combustible liquide contenu dans une poêle avec plus d'efficacité qu'un système de gicleurs mousse-eau, et procurer une protection contre la réinflammation supérieure à celui-ci, tel qu'indiquée dans la norme UL162, Foam Equipment and Liquid Concentrates. L'industrie s'est dite préoccupée par les variations possibles de la densité de la MSP en raison de la fluctuation de la pression d'alimentation en eau. On décrit dans ce document une série d'essais de réaction au feu de classe B en vraie grandeur, conçus pour établir les densités fournies minimales et maximales de MSP suivant la variation des valeurs de pression d'alimentation en eau. Un facteur de sécurité pourrait alors être associé à la densité normale d'application de calcul.

Compressed-air foam (CAF) has been proven to be an effective fire suppression material for both class A and B fires. Comparison testing between CAF and standard foam water sprinklers had been conducted previously to quantify the amount of foam required to extinguish a liquid fuel fire that was contained within the bounds of a pan as specified in the UL162 Foam Equipment and Liquid Concentrates standard. To date only a few smaller scale tests had been conducted using CAF to extinguish free flowing spill fires. This paper describes a series of full-scale Class B fire tests designed to compare CAF (Compressed-air Foam) and standard foam water sprinklers in extinguishing free flowing spill fires with and without shielded areas., Il a été prouvé que la mousse sous pression (MSP) est un agent d'extinction efficace pour les feux tant de classe A que de classe B. Des tests de comparaison entre la MSP et les gicleurs mousse-eau standard avait été réalisés auparavant afin de quantifier la mousse requise pour éteindre un feu de combustible liquide contenu à l'intérieur d'une poêle, tel qu'indiqué dans la norme UL162, Foam Equipment and Liquid Concentrates. À ce jour, seuls quelques essais à plus petite échelle ont été menés avec de la MSP pour éteindre des feux de liquide inflammable en écoulement libre. On décrit dans ce document une série d'essais de réaction au feu de classe B, en vraie grandeur, conçus aux fins de la comparaison de l'efficacité de la MSP et de celle des gicleurs mousse-eau standard pour éteindre des feux de liquide inflammable en écoulement libre, avec et sans écrans de protection.

Air aspirated foam is created close to or in the nozzle by entraining air with a water jet and impacting on one or more obstacles. Some of the energy of the stream is used to agitate the mixture and foam is produced. 'Foam-water' refers to a foam solution of water and foam concentrate that has not been expanded by air. Compressed-air foam (CAF) has been proven to be an effective fire suppression material for both Class A and B fires, however, the effectiveness of CAF compared to air-aspirated systems and foam water systems has not yet been quantified. While air-aspirated foam systems have been around for many years the development of high quality Aqueous Film-Forming Foam (AFFF) concentrates have allowed foam systems with little or no air expansion to be used in controlling large flammable liquid fuel fires. To effectively compare these systems a series of 22 full scale fire tests were conducted with CAF, air-aspirated foam and foam water solution using 4.64 m2 pool fire. This paper describes a series of 22 full scale Class B fire tests designed to compare CAF, air-aspirated, and foam water solution in extinguishing a 4.64 m2 pool fire in accordance with the CAN/ULC-S560-98 Standard for Category 3 Aqueous Film-Forming Foam (AFFF) Liquid Concentrates [1]. In addition to visual observations, radiant heat flux was also measured at a point 1.83 m from the edge of the fuel pan and 1.5 m off the ground., 8th Fire Suppression and Detection Research Application Symposium: 21 January 2004, Orlando, Florida

Fixed pipe compressed-air foam (CAF) systems have been developed over the past decade through a research collaboration between the National Research Council of Canada (NRCC) and the Department of National Defence. Prototype CAF systems have demonstrated, through full-scale testing [1-3], their superior fire suppression performance for controlling and extinguishing fires for a number of hazards, including flammable liquids. To date, however, no detailed comparison testing with other similar fire suppression systems for flammable liquids has been undertaken.Fixed pipe CAF systems represent a major innovation in fire suppression technology. By injecting air into a foam-water stream in a mixing chamber, a significantly superior foam is produced primarily as a result of uniform, small bubble sizes. That foam is transported through a piping system to rotary nozzles which distribute foam over a prescribed area. There are currently no specific fire suppression performance or installation standards for CAF systems; thus, to assess the new technology for potential applications, comparisons must be made using existing standards for similar fire suppression systems., Le système d'extinction par mousse à air comprimé (CAF) a été élaboré au cours de la dernière décennie dans le cadre d'une collaboration entre le Conseil national de recherches du Canada (CNRC) et le ministère de la Défense nationale. Le prototype a montré, lors d'essais à grandeur réelle [1-3], que le système CAF avait la meilleure performance extinctrice devant un grand nombre de situations dangereuses, y compris devant les incendies de liquides inflammables. Toutefois, à ce jour, il n'existe encore aucune étude comparative détaillée avec d'autres systèmes d'extinction dans cette dernière situation. Le système CAF représente une importante innovation dans les techniques d'extinction. L'injection d'air dans un jet de mousse et d'eau qui passe dans une chambre de mélange, produit une mousse supérieure en quantité et en qualité, résultat du mélange de bulles uniformes et de petite taille. Cette mousse est transportée par un système de tuyaux vers des buses rotatives qui la distribuent dans une zone déterminée. Il n'existe pour l'heure aucune performance mesurée ni de norme d'installation pour le système CAF; il est donc urgent, si l'on veut évaluer les applications possibles de cette nouvelle technologie, de la comparer en fonction des normes en vigueur de systèmes d'extinction d'incendie comparables.

Aussi disponible en français: Nouveau système d'extinction par mousse à air comprimé pour les hangars d'avions

In recent years, with the halon phase-out, there has been a major thrust towards finding new advanced fire suppression systems. Some of the newly developed fire suppression systems include halocarbon and inert gaseous agents, water mist systems, compressed-air-foam systems, and aerosol and gas generators. Halocarbon agents are chemicals similar to halon except that its molecular structure was modified to reduce or eliminate the chlorine and bromine atoms that are responsible for ozone depletion. They can extinguish fires at their design concentration, however, they produce Thermal Decomposition Products (TDP) including hydrogen fluoride (HF) at much higher levels than halon. Inert gas agents extinguish fire by oxygen depletion. They have zero ODP and no Global Warming potential, and they are not subject to thermal decomposition when used in extinguishing fires. However, they require high-pressure storage cylinders which has implications for space and weight. Fire suppression by water mist is mainly by a physical mechanism. Water mist fire suppression systems have demonstrated a number of advantages, such as good fire suppression capability, no environmental impact and no toxicity. However, water mist does not behave like a total flooding agent, thus the fire suppression effectiveness of water mist depends on the potential size of the fire, properties of the combustibles, and the degree of obstruction, as well as the water mist characteristics. Aerosol systems produce micron size dry chemical particles and gas products, and extinguish fires by removing and recombining flame propagation radicals and by absorbing heat. Gas generators produce a large quantity of inert gases by combustion of solid propellants, and extinguish fires by oxygen depletion. All of the recently developed fire suppression systems extinguish fires at their design conditions, however, no one system can be chosen as the best system for all applications. Some perform better than others in a particular application. All have some limitations and concerns that have to be dealt with in extinguishing fires., Aussi disponible en français: Vue d'ensemble de l'état d'avancement en matière de technologie de l'extinction des incendies, Invited Keynote Lecture at the 2nd NRIFD Symposium Proceedings: 17 July 2002, Tokyo, Japan

National Research Council (NRC), in collaboration with National Defence Canada (DND), has initiated a project to investigate the feasibility of using a newly-developed compressed-air-foam (CAF) fire suppression system to provide fire safety protection to aircrafts and hangar structures. Previous research has indicated that such an objective can be met if the fire suppression system achieves 90% control of the fire in 30 s and extinguishment in 60 s. As a part of this project, a prototype CAF protection system was developed and evaluated to determine whether it meets the project objective. Fire suppression tests of the prototype CAF system with three simulated aircraft hangar fire scenarios, provide technical evidence that the CAF system can meet the fire protection objective using a combination of overhead CAF nozzles and portable low-level nozzles, which could be located near each aircraft to suppress any fire that would be concealed from the overhead nozzles., Interflam 2001, Proceedings of the Ninth International Conference: 17 September 2001, Edinburgh, UK

Proceedings of Halon Options Technical Working Conference 2000 (HOTWC 2000): 02 May 2000, Albuquerque, New Mexico

Fire fighting foam has been in use in the Fire Services for over 75 years. It was originally designed as a surfactant to improve the absorption of water into Class A combustibles such as wood and paper. It quickly found use in fighting flammable liquid spill fires since the foam could float on the surface of the burning fuel and extinguish the fire by sealing off the surface. This separates, the fuel from the flame, absorbs the fuel vapour and prevents thermal feedback to the fuel. As a result, foam concentrates evolved along two lines: AFFF or "Aqueous Film Forming Foams" for Class B or liquid fires and Class A for wildland and structural fires.

Proceedings of Fire Suppression and Detection Research Application Symposium: 24 February 1999, Orlando, Florida

98' International Symposium on Safety Science and Technology: 07 October 1998, Beijing, China

International Wildland Fire Foam Symposium and Workshop: 03 May 1994, Thunder Bay, Ont., Canada

International Conference on Fire Research and Engineering: 10 September 1995, Orlando, Florida, USA