Portable Fire Extinguishers

Transcription

1 Portable Fire Extinguishers Chapter Overview With its self-contained features, transportability, ease of use, varied style, and application, the portable fire extinguisher may well be the unsung hero of fire suppression. Despite today s climate of technological advances, and newer, bigger, and more sophisticated apparatus and equipment, this simple yet valuable tool warrants a second look as a first line of defense for fire fighters. After students complete this chapter and the related course work, they will be able to state the primary purpose of portable fire extinguishers. Students will have an understanding of portable fire extinguishers, including the types of agents and operating systems used, the classification and rating system for fire extinguishers, and the basic steps of fire extinguisher operation. Students will also be able to define Class A, B, C, D, and K fires, and identify the safe and effective suppression methods for each. In addition, students will be able to explain the care and maintenance of portable fire extinguishers, including recharging and hydrostatic testing. NFPA 1001 Standard Fire Fighter I Extinguish incipient Class A, Class B, and Class C fires, given a selection of portable fire extinguishers, so that the correct extinguisher is chosen, the fire is completely extinguished, and correct extinguisherhandling techniques are followed. [p , , ] (A) Requisite Knowledge. The classifications of fire; the types of, rating systems for, and risks associated with each class of fire; and the operating methods and limitations of portable fire extinguishers. [p , , ] (B) Requisite Skills. The ability to operate portable fire extinguishers, approach fire with portable fire extinguishers, select an appropriate extinguisher based on the size and type of fire, and safely carry portable fire extinguishers. [p ] Fire Fighter II NFPA 1001 contains no Fire Fighter II Job Performance Requirements for this chapter. Additional NFPA Standards NFPA 10, Standard for Portable Fire Extinguishers NFPA 11, Standard for Low-, Medium-, and High- Expansion Foam Objectives and Resources Knowledge Objectives After studying this chapter, you will be able to: State the primary purposes of fire extinguishers. Define Class A fires. Define Class B fires. Define Class C fires. Define Class D fires. Define Class K fires. Explain the classification and rating system for fire extinguishers. Describe the types of agents used in fire extinguishers. Describe the types of operating systems in fire extinguishers.

2 Chapter 7 Describe the basic steps of fire extinguisher operation. Explain the basic steps of inspecting, maintaining, recharging, and hydrostatic testing of fire extinguishers. Skills Objectives After studying this chapter, you will be able to perform the following skills: Transport the extinguisher to the location of the fire. Operate a carbon dioxide extinguisher. Attack a Class A fire with a stored-pressure water-type fire extinguisher. Attack a Class A fire with a multipurpose dry chemical fire extinguisher. Attack a Class B flammable liquid fire with a dry chemical fire extinguisher. Attack a Class B flammable liquid fire with a stored-pressure foam fire extinguisher. Use a wet chemical (Class K) fire extinguisher. Use a halogenated agent-type extinguisher. Use dry powder fire-extinguishing agents. Support Materials Dry erase board and markers or chalkboard and chalk LCD projector, slide projector, overhead projector, and projection screen PowerPoint presentation, overhead transparencies, or slides Assortment of portable fire extinguishers to enable each student to discharge Eye protection (instructor and students) for hands-on demonstration and practice Enhancements Direct the students to visit the Internet at for online activities. Direct the students to relevant sections in the Student Workbook for application of the content introduced in this chapter. Direct the students to relevant sections in the Student Review Manual to prepare for examinations. Direct the students to the corresponding online FireLearn module to study the knowledge and critical thinking skills presented online. Teaching Tips Contact a local equipment vendor for samples and literature. Assemble an assortment of portable extinguishers, including several of the obsolete (carbon tetrachloride, sodium bicarbonate) extinguishers to illustrate the evolving technology and safety considerations. Consider a triad teach back to confirm inspection and maintenance skills. Place students in groups of three (multiples of three) and assemble portable extinguishers in sets of three (multiples of three). Label the units and allow students to select from cards labeled Each student demonstrates an inspection and states maintenance considerations for the respective unit. Rotate groups as supplies allow. Obtain a copy of NFPA 10, Standard for Portable Fire Extinguishers, and the NFPA Fire Protection Handbook for classroom reference. Skill Drill steps are included prior to the section on maintenance. Depending on your audience analysis, you may want to break the class prior to discussing inspection, maintenance, recharging, and hydrostatic testing for hands-on demonstrations and practice, and then reconvene to cover care and maintenance issues. This breaks up the amount of information and allows students to apply newly-received information. To aid in recognition of fire classifications, create a mnemonic or memory-jogger such as the following: Class A fires reduce material to ash; Class B materials usually are stored in bottles; Class C materials usually involve current; Class D materials react dramatically to water; and Class K materials usually are involved with kitchens.

3 146 Fire Service Instructor: Principles and Practice, Second Edition Reading and Preparation Review all instructional materials, including Fundamentals of Fire Fighter Skills, Chapter 7, and all related presentation support materials. Review local firefighting protocols for Chapter 7. Review Chapter 1, The History and Orientation of the Fire Service, Chapter 5, Fire Behavior, Chapter 16, Fire Hose, Nozzles, Streams, and Foam, Chapter 20, Wildland and Ground Fires, and Chapter 21, Fire Suppression, in Fundamentals of Fire Fighter Skills to provide a context for supporting the use of fire extinguishers in today s fire service. Use this as a motivator for anticipating future classes. Familiarize yourself with the content of NFPA 10, Standard for Portable Fire Extinguishers, and NFPA 11, Standard for Low-, Medium-, and High-Expansion Foam Systems, to be prepared to respond to student questions and/or expand on elements of the text and lesson plan. Prepare a job sheet, series of flash cards, or posters to reinforce identification of extinguisher labels and extinguisher classifications and ratings. Assign as homework or use for an in-class review.

4 Chapter 7: Portable Fire Extinguishers 147 Presentation Overview Total time: 475 minutes Pre-Lecture I. You Are the Fire Fighter Small Group Activity/Discussion 5 minutes Fire Fighter I Lecture I. Introduction Lecture/Discussion 5 minutes Fire Fighter I II. Purposes of Fire Extinguishers Lecture/Discussion 5 minutes Fire Fighter I III. Classes of Fires Lecture/Discussion 15 minutes Fire Fighter I IV. Classification of Fire Extinguishers Lecture/Discussion 15 minutes Fire Fighter I V. Labeling of Fire Extinguishers Lecture/Discussion 15 minutes Fire Fighter I VI. Fire Extinguisher Placement Lecture/Discussion 20 minutes Fire Fighter I VII. Methods of Fire Extinguishment Lecture/Discussion 5 minutes Fire Fighter I VIII. Types of Extinguishing Agents Lecture/Discussion 65 minutes Fire Fighter I IX. Fire Extinguisher Design Lecture/Discussion 15 minutes Fire Fighter I X. Fire Extinguisher Characteristics Lecture/Discussion 40 minutes Fire Fighter I XI. Use of Fire Extinguishers Lecture/Discussion/Demonstration 50 Minutes Fire Fighter I XII. The Care of Fire Extinguishers: Lecture/Discussion 15 minutes Fire Fighter I Inspection, Maintenance, Recharging, and Hydrostatic Testing XIII. Summary Lecture/Discussion 15 minutes Fire Fighter I XIV. Skill Drills Demonstration/Group Activity 135 minutes Fire Fighter I A. Transporting a Fire Extinguisher (Skill Drill 7-1, Fire Fighter I) B. Operating a Carbon Dioxide Extinguisher (Skill Drill 7-2, Fire Fighter I) C. Attacking a Class A Fire with a Stored-Pressure Water-Type Fire Extinguisher (Skill Drill 7-3, Fire Fighter I) D. Attacking a Class A Fire with a Multipurpose Dry Chemical Fire Extinguisher (Skill Drill 7-4, Fire Fighter I) E. Attack a Class B Flammable Liquid Fire with a Dry Chemical Fire Extinguisher (Skill Drill 7-5, Fire Fighter I) F. Attacking a Class B Flammable Liquid Fire with a Stored-Pressure Foam Fire Extinguisher (AFFF or FFFP) (Skill Drill 7-6, Fire Fighter I) G. Using a Wet Chemical Fire Extinguisher (Skill Drill 7-7, Fire Fighter I) H. Use of Halogenated-Agent Extinguisher (Skill Drill 7-8, Fire Fighter I) I. Use of Dry Powder Fire Extinguishing Agents (Skill Drill 7-9, Fire Fighter I) Post-Lecture I. Wrap-Up Activities Small Group Activity/Individual 40 minutes Fire Fighter I Activity/Discussion A. Fire Fighter in Action B. Technology Resources ( II. Lesson Review Discussion 15 minutes Fire Fighter I III. Assignments Lecture 5 minutes Fire Fighter I

5 148 Fire Service Instructor: Principles and Practice, Second Edition Lesson Plan Pre-Lecture You Are the Fire Fighter Time: 5 Minutes Level: Fire Fighter I Small Group Activity/Discussion Use this activity to motivate students to learn the knowledge and skills needed to safely and effectively use portable fire extinguishers. Purpose To allow students an opportunity to explore the significance and concerns associated with portable fire extinguishers. Instructor Directions 1. Direct students to read the You Are the Fire Fighter scenario found in the beginning of Chapter You may assign students to a partner or a group. Direct them to review the discussion questions at the end of the scenario and prepare a response to each question. Facilitate a class dialogue centered on the discussion questions. 3. You may also assign this as an individual activity and ask students to turn in their comments on a separate piece of paper. Lesson Plan Lecture I. Introduction Time: 5 Minutes Slides: 1-6 Level: Fire Fighter I Lecture/Discussion Slides 1-4 Chapter Objectives A. Fire Extinguishers Slide 5 Introduction (1 of 2) Portable fire extinguishers are required in a variety of occupancies. Extinguishers are used by citizens and fire fighters. Easy to operate with minimal training 1. Portable fire extinguishers are required in a variety of occupancies. a. Citizens are encouraged to keep fire extinguishers in their home, particularly in their kitchen. b. Most extinguishers are easy to operate with a minimal amount of training.

6 Chapter 7: Portable Fire Extinguishers 149 Slide 6 Introduction (2 of 2) Extinguishers vary in size and type of extinguishing agent used. Selection of appropriate extinguisher is critical. Proper use reduces injury and property damage. 2. Extinguishers vary in size and type of extinguishing agent used. a. Agents include water, water with additives, dry chemicals, dry powders, and gaseous agents. b. Each agent is suitable for specific types of fires. 3. Extinguishers are designed for different purposes; selecting the appropriate extinguisher and knowing how to safely operate it is critical. 4. Fire fighters use extinguishers to control small fires that do not require the use of a hose line. a. Portable backpack-type fire extinguisher used to control and overhaul a wildland fire b. Special types of fire extinguishers are appropriate for situations where the application of water would be dangerous, ineffective, or undesirable. II. Purposes of Fire Extinguishers Time: 5 Minutes Slides: 7-8 Level: Fire Fighter I Lecture/Discussion Slide 7 Purposes of Fire Extinguishers (1 of 2) Extinguish incipient fires Control fires where traditional suppression methods not recommended Most departments carry at least one. Often used by fire fighters for incipient fires A. Introduction to Purposes of Fire Extinguishers 1. Primary uses a. Extinguish incipient fires (those that have not spread beyond the area of origin) b. Control fires where traditional methods of fire suppression are not recommended 2. Fire extinguishers are placed in many locations so that they will be available for immediate use on small, incipient fires. a. A trained individual with a suitable fire extinguisher could easily control this type of fire. b. As the flames spread beyond the area of origin, the fire becomes increasingly difficult to control with only a portable fire extinguisher. 3. Fire extinguishers are also used to control fires where traditional extinguishing methods are not recommended. a. Using water on fires that involve energized electrical equipment increases the risk of electrocution to fire fighters. b. Special extinguishing agents are also required for fires that involve flammable liquids, cooking oils, and combustible metals. B. Use of Portable Fire Extinguishers in Incipient Fires 1. Most fire department vehicles carry at least one fire extinguisher; many vehicles carry two or more extinguishers of different types. 2. Fire fighters often use these portable extinguishers to control incipient fires quickly. a. One advantage of fire extinguishers is their portability. b. The primary disadvantage of fire extinguishers is that they are one-shot devices.

7 150 Fire Service Instructor: Principles and Practice, Second Edition Slide 8 Purposes of Fire Extinguishers (2 of 2) Must know Which fires require special extinguishing agents What type of extinguisher to use How to operate each type of extinguisher C. Special Extinguishing Agents 1. As a fire fighter, you must know which fires require special extinguishing agents, what type of extinguisher should be used, and how to operate the different types of special-purpose extinguishers. a. Portable extinguishers are sometimes used in combination with other techniques. b. Certain types of portable extinguishers can be helpful in overhauling a fire. III. Classes of Fires Time: 15 Minutes Slides: 9-14 Level: Fire Fighter I Lecture/Discussion Slide 9 Classes of Fires Essential to match extinguisher and fire Grouped by their characteristics Some agents are more efficient on certain fires. Some agents will not control certain fires. Some agents are dangerous when applied to certain fires. Slide 10 Class A Fires Class A fires involve items such as: Ordinary wood Rubber Household rubbish Natural vegetation Water is most common extinguishing agent. A. It is essential to match the appropriate type of extinguisher to the type of fire. 1. Fires and fire extinguishers are grouped into classes according to their characteristics. a. Some extinguishing agents work more efficiently than others on certain types of fires. b. In some cases, selecting the proper extinguishing agent will mean the difference between extinguishing a fire and being unable to control it. c. More importantly, in some cases it is dangerous to apply the wrong extinguishing agent to a fire. d. Using a water extinguisher on an electrical fire can cause an electrical shock as well as a short circuit in the equipment. e. A water extinguisher should never be used to fight a grease fire. 2. Before selecting a fire extinguisher, ask yourself, What class of fire am I fighting? B. Class A Fires 1. Involve ordinary combustibles such as wood, paper, cloth, rubber, household rubbish, and some plastics. 2. Natural vegetation, such as grass and trees, is also Class A material. 3. Water is the most commonly used extinguishing agent for Class A fires, although several other agents can be used effectively. Slide 11 Class B Fires Class B fires involve items such as: Flammable liquids and gases Oil and grease Tar Some plastics Several agents can be used. C. Class B Fires 1. Involve flammable or combustible liquids, such as gasoline, oil, grease, tar, lacquer, oil-based paints, and some plastics. 2. Fires involving flammable gases, such as propane or natural gas, are also categorized as Class B fires. 3. Several different types of extinguishing agents are approved for Class B fires.

8 Chapter 7: Portable Fire Extinguishers 151 Slide 12 Class C Fires Class C fires involve energized electrical equipment such as: Building wiring Circuit breakers Transformers Power tools Require agents that are not conductors Slide 13 Class D Fires Class D fires involve combustible metals. Magnesium Sodium Lithium Potassium Violent reactions to water and other agents can occur. Slide 14 Class K Fires New classification due to cooking trends Involve combustible cooking oils and fats Some restaurants still use Class B extinguishers. D. Class C Fires 1. Involve energized electrical equipment, which includes any device that uses, produces, or delivers electrical energy. 2. A Class C fire could involve building wiring and outlets, fuse boxes, circuit breakers, transformers, generators, or electric motors. 3. Power tools, lighting fixtures, household appliances, and electronic devices such as televisions, radios, and computers could be involved in Class C fires. 4. The equipment must be plugged in or connected to an electrical source, but not necessarily operating. 5. Electricity does not burn, but electrical energy can generate tremendous heat that could ignite nearby Class A or B materials. 6. As long as the equipment is energized, it must be treated as a Class C fire. 7. Agents that will not conduct electricity, such as dry chemicals or carbon dioxide, must be used on Class C fires. E. Class D Fires 1. Involve combustible metals such as magnesium, titanium, zirconium, sodium, lithium, and potassium. 2. Special techniques and extinguishing agents are required to fight combustible metals fires. 3. Normal extinguishing agents can react violently, even explosively, if they come in contact with burning metals. 4. Violent reactions also can occur when water strikes burning combustible metals. 5. Class D fires are most often encountered in industrial occupancies, such as machine shops and repair shops, as well as in fires involving aircraft and automobiles. 6. Because of the chemical reactions that could occur during a Class D fire, it is important to select the proper extinguishing agent and application technique. 7. Choosing the correct fire extinguisher for a Class D fire requires expert knowledge and experience. F. Class K Fires 1. Involve combustible cooking oils and fats. 2. The use of high-efficiency modern cooking equipment and the trend toward using vegetable oils instead of animal fats to fry foods required the development of a new class of extinguishing agents. 3. Many restaurants are still using extinguishing agents that were approved for Class B fires.

9 152 Fire Service Instructor: Principles and Practice, Second Edition IV. Classification of Fire Extinguishers Time: 15 Minutes Slides: Level: Fire Fighter I Lecture/Discussion Slide 15 Classification of Fire Extinguishers (1 of 5) Classification and rating are based on characteristics and capabilities. Underwriters Laboratories, Inc. (UL) develops standards for ratings and classification. Rated for safety and effectiveness May have multiple letters if effective on more than one class of fire Slide 16 Classification of Fire Extinguishers (2 of 5) Letters indicate class of fire for which extinguisher can be used. Numbers indicate effectiveness for Class A and B extinguishers by a nonexpert user. Slide 17 Classification of Fire Extinguishers (3 of 5) Class A fire extinguishers Number is related to amount of water. 1-A rated contains equivalent of 1.25 gallons of water. 2-A rated contains equivalent of 2.5 gallons of water. 4-A rated should extinguish approximately twice as much fire as a 2-A rated. Slide 18 Classification of Fire Extinguishers (4 of 5) Class B fire extinguishers Number is based on approximate square feet of burning fuel that can be extinguished. 10-B rated will extinguish 10 square feet of fire. 40-B rated will extinguish 40 square feet of fire. A. Portable fire extinguishers are classified and rated based on their characteristics and capabilities. 1. This information is important for selecting the proper extinguisher to fight a particular fire. 2. It is also used to determine what type or types of fire extinguishers should be placed in a given location so that incipient fires can be quickly controlled. B. In the United States, Underwriters Laboratories, Inc. (UL), is the organization that developed the standards, classification, and rating system for portable fire extinguishers. 1. Each fire extinguisher has a specific rating that identifies the class or classes of fires for which it is both safe and effective. C. The classification system for fire extinguishers uses letters and numbers. 1. The letters indicate the class or classes of fire for which the extinguisher can be used. 2. The numbers indicate its effectiveness. 3. Fire extinguishers that are safe and effective for more than one class will be rated with multiple letters. 4. Class A and Class B fire extinguishers also include a number, indicating the relative effectiveness of the fire extinguisher in the hands of a nonexpert user. 5. On Class A extinguishers, the number is related to an amount of water. a. An extinguisher that is rated 1-A contains the equivalent of 1.25 gallons of water. b. A typical Class A extinguisher contains 2.5 gallons of water and has a 2-A rating. c. The higher the number, the greater the extinguishing capability of the extinguisher. d. The effectiveness of Class B extinguishers is based on the approximate area (measured in square feet) of burning fuel they are capable of extinguishing. e. A 10-B rating indicates that a nonexpert user should be able to extinguish a fire in a pan of flammable liquid that is 10 square feet in surface area. f. An extinguisher rated 40-B should be able to control a flammable liquid pan fire with a surface area of 40 square feet. 6. Numbers are used to rate an extinguisher s effectiveness only for Class A and Class B fires.

10 Chapter 7: Portable Fire Extinguishers 153 Slide 19 Classification of Fire Extinguishers (5 of 5) Class C extinguishers use agents that do not conduct electricity. Standard test fires Used to rate the effectiveness of fire extinguishers May involve different agents, amounts, application rates, and application amounts 7. If the fire extinguisher can also be used for Class C fires, it contains an agent proven to be nonconductive to electricity and safe for use on energized electrical equipment. a. For instance, a fire extinguisher that carries a 2-A:10-B:C rating can be used on Class A, Class B, and Class C fires. b. It has the extinguishing capabilities of a 2-A extinguisher when applied to Class A fires, the capabilities of a 10-B extinguisher for Class B fires, and can be used safely on energized electrical equipment. D. Standard test fires are used to rate the effectiveness of fire extinguishers. 1. The testing may involve different agents, amounts, application rates, and application methods. 2. Fire extinguishers are rated for their ability to control a specific type of fire as well as for the extinguishing agent s ability to prevent rekindling. 3. Some agents can successfully suppress a fire but are unable to prevent the material from re-igniting. 4. A rating is only given if the extinguisher completely extinguishes the standard test fire and prevents rekindling. V. Labeling of Fire Extinguishers Time: 15 Minutes Slides: Level: Fire Fighter I Lecture/Discussion Slide 20 Labeling of Fire Extinguishers (1 of 3) Traditional lettering system: Class A = Green triangle Class B = Red square Class C = Blue circle Class D = Yellow star No traditional label for Class K A. Introduction to the Labeling of Fire Extinguishers 1. Fire extinguishers that have been tested and approved by an independent laboratory are labeled to clearly designate the class or classes of fire the unit is capable of extinguishing safely. 2. The traditional lettering system has been used for many years and is still found on many fire extinguishers. 3. Recently, however, a universal pictograph system, which does not require the user to be familiar with the alphabetic codes for the different classes of fires, has been developed. Slide 21 Labeling of Fire Extinguishers (2 of 3) Pictograph system: Square icons represent each class of fire. Class A, Class B, Class C, and Class K have pictographs. B. The Traditional Lettering System 1. Extinguishers suitable for use on Class A fires are identified by the letter A on a solid green triangle. 2. Extinguishers suitable for use on Class B fires are identified by the letter B on a solid red square. 3. Extinguishers suitable for use on Class C fires are identified by the letter C on a solid blue circle. 4. Extinguishers suitable for use on Class D fires are identified by the letter D on a solid yellow five-pointed star. 5. Extinguishers suitable for use on Class K (combustible cooking oil) fires are identified by a pictograph showing a fire in a frying pan. Because the Class K designation is new, there is no traditional system alphabet graphic for it.

11 154 Fire Service Instructor: Principles and Practice, Second Edition Slide 22 Labeling of Fire Extinguishers (3 of 3) Icon represents the rating for the class of fire. No icon = no rating Red slash indicates that the extinguisher must not be used on that type of fire. C. Pictograph Labeling System 1. Uses symbols rather than letters on the labels 2. This system also clearly indicates if an extinguisher is inappropriate for use on a particular class of fire. 3. The pictographs are all square icons that are designed to represent each class of fire. a. The icon for Class A fires is a burning trash can beside a wood fire. b. The Class B fire extinguisher icon is a flame and a gasoline can. c. The Class C icon is a flame and an electrical plug and socket. d. There is no pictograph for Class D extinguishers. e. Extinguishers rated for fighting Class K fires are labeled with an icon showing a fire in the frying pan. 4. Under this pictograph labeling system, the presence of an icon indicates that the extinguisher has been rated for that class of fire. 5. A missing icon indicates that the extinguisher has not been rated for that class of fire. 6. A red slash across an icon indicates that the extinguisher must not be used on that type of fire, because doing so would create additional risk. VI. Fire Extinguisher Placement Time: 20 minutes Slides: Level: Fire Fighter I Lecture/Discussion Slide 23 Fire Extinguisher Placement (1 of 3) National Fire Protection Association (NFPA) 10 lists recommendations for placing and mounting portable fire extinguishers. Occupancy regulations specify area protected, travel distance from extinguisher to fire, and types of extinguishers provided. A. Introduction to Fire Extinguisher Placement 1. Fire codes and regulations require the installation of fire extinguishers in many areas so that they will be available to fight incipient fires. 2. NFPA Standard 10 lists the recommendations for placing and mounting portable fire extinguishers as well as the recommended mounting heights. 3. The regulations for each type of occupancy specify the maximum floor area that can be protected by each extinguisher, the maximum travel distance from the closest extinguisher to a potential fire, and the types of fire extinguishers that should be provided. Slide 24 Fire Extinguisher Placement (2 of 3) Two factors to consider to determine the type of extinguisher: Class of fire likely to occur Potential magnitude of an incipient fire 4. Two key factors must be considered when determining which type of extinguisher should be placed in each area: the class of fire that is likely to occur and the potential magnitude of an incipient fire.

12 Chapter 7: Portable Fire Extinguishers 155 Slide 25 Fire Extinguisher Placement (3 of 3) Extinguishers should be readily visible and easily accessed. Do not mount heavy extinguishers high on a wall. NFPA 10 recommends mounting heights. Slide 26 Classifying Area Hazards Fire load Quantity of combustible materials present Includes building materials, contents, and furnishings Measured as the average weight of combustibles per square foot The larger the load, the larger the potential fire 5. Extinguishers should be mounted so they are readily visible and easily accessed. 6. According to NFPA Standard 10, the recommended mounting heights for the placement of fire extinguishers are: a. Fire extinguishers weighing up to 40 lb (18.14 kg) should be mounted so that the top of the extinguisher is not more than 5 (1.53 m) above the floor. b. Fire extinguishers weighing more than 40 lb (18.14 kg) should be mounted so that the top of the extinguisher is not more than 3 (1.07 m) above the floor. c. The bottom of an extinguisher should be at least 4 (10.2 cm) above the floor. B. Classifying Area Hazards 1. Areas are divided into three risk classifications light, ordinary, and extra hazard according to the amount and type of combustibles that are present, including building materials, contents, decorations, and furniture. 2. Occupancy use category does not necessarily determine the appropriate hazard classification. a. The recommended hazard classifications for different types of occupancies are guidelines, based on typical situations. b. The hazard classification for each area should be based on the actual amount and type of combustibles that are present. Slide 27 Light or Low Hazard (1 of 2) Areas where the majority of materials are noncombustible Arranged so that a fire is not likely to spread Contain limited amounts of Class A and Class B combustibles 3. Light (low) hazard a. Areas where the majority of materials are noncombustible or arranged so that a fire is not likely to spread b. Light hazard environments usually contain limited amounts of Class A combustibles, such as wood, paper products, cloth, and similar materials. c. A light hazard environment might also contain some Class B combustibles (flammable liquids and gases), such as copy machine chemicals or modest quantities of paints and solvents, but all Class B materials must be kept in closed containers and stored safely. Slide 28 Light or Low Hazard (2 of 2) Common light hazard environments include: Offices Classrooms Churches Hotel guest rooms d. Examples of common light hazard environments are most offices, classrooms, churches, assembly halls, and hotel guest rooms.

13 156 Fire Service Instructor: Principles and Practice, Second Edition Slide 29 Ordinary or Moderate Hazard Contain more Class A and Class B materials than light hazard locations Examples include: Auto showrooms Research facilities Parking garages Slide 30 Extra or High Hazard (1 of 2) Contain more Class A and Class B materials than ordinary hazard locations Class I commodities Class II commodities 4. Ordinary (moderate) hazard a. Contain more Class A and Class B materials than are found in light hazard locations b. Typical examples of ordinary hazard locations include retail stores with on-site storage areas, light manufacturing facilities, auto showrooms, parking garages, research facilities, and workshops or service areas that support light hazard locations, such as hotel laundry rooms or restaurant kitchens. c. Ordinary hazard areas also include warehouses that contain Class I and Class II commodities. i. Class I commodities include noncombustible products stored on wooden pallets or in corrugated cartons that are shrink-wrapped or wrapped in paper. ii. Class II commodities include noncombustible products stored in wooden crates or multilayered corrugated cartons. 5. Extra (high) hazard a. Locations that contain more Class A combustibles and/or Class B flammables than are found in ordinary hazard environments. Slide 31 Extra or High Hazard (2 of 2) Examples include: Woodworking shops Kitchens that have deep fryers, flammable liquids, or gases under pressure Facilities used for storing flammable liquids b. Typical examples of extra hazard areas include woodworking shops; service or repair facilities for cars, aircraft, or boats; and many kitchens and other cooking areas that have deep fryers, flammable liquids, or gases under pressure. c. In addition, areas used for manufacturing processes such as painting, dipping, or coating, and facilities used for storing or handling flammable liquids are classified as extra hazard environments. d. Warehouses containing products that do not meet the definitions of Class I and Class II commodities are also considered extra hazard locations. Slide 32 Determining the Appropriate Placement of Fire Extinguishers Consider the types and quantities of fuels found in the area. Multipurpose dry chemical extinguishers are often used in areas containing low to moderate hazards. Facilities present a variety of conditions. Evaluate each area and tailor the installation. C. Determining the Most Appropriate Placement of Fire Extinguishers 1. Several factors must be considered when determining the number and types of fire extinguishers that should be placed in each area of an occupancy. 2. Among these factors are the types of fuels found in the area and the quantities of those materials. 3. Some areas may need extinguishers with more than one rating or more than one type of fire extinguisher. 4. Most buildings require extinguishers that are suitable for fighting Class A fires because ordinary combustible materials, such as furniture, partitions, interior finish materials, paper and packaging products, are so common. 5. A single multipurpose extinguisher is generally less expensive than two individual fire extinguishers and eliminates the problem of selecting the proper extinguisher for a particular fire. 6. However, it is sometimes more appropriate to install Class A extinguishers in general use areas and to place extinguishers that are especially effective in fighting Class B or Class C fires near those hazards.

14 Chapter 7: Portable Fire Extinguishers Some facilities present a variety of conditions. In these occupancies, each area must be individually evaluated so that extinguisher installation is tailored to the particular circumstances. VII. Methods of Fire Extinguishment Time: 5 Minutes Slides: Level: Fire Fighter I Lecture/Discussion Slide 33 Methods of Fire Extinguishment (1 of 2) Fires require fuel, heat, and oxygen. Rapid oxidation Occurs when a fuel is combined with oxygen Combustion Occurs when fuel is heated to its kindling temperature Slide 34 Methods of Fire Extinguishment (2 of 2) Extinguishers stop burning by: Cooling the fuel Cutting off the supply of oxygen Interrupting the chain of reactions A. Introduction to Methods of Fire Extinguishment 1. Understanding the nature of fire is key to understanding how extinguishing agents work and how they differ from each other. 2. All fires require three basic ingredients: fuel, heat, and oxygen. 3. Scientifically, burning is called rapid oxidation. a. It is a chemical process that occurs when a fuel is combined with oxygen, resulting in the formation of ash or other waste products and the release of energy as heat and light. 4. The combustion process begins when the fuel is heated to its kindling temperature (also known as the kindling point or ignition point) the temperature at which it begins to burn. 5. The energy that initiates the process can come from many different sources, including a spark or flame, friction, electrical energy, or a chemical reaction. 6. Once a substance begins to burn, it will generally continue burning as long as there are adequate supplies of oxygen and fuel to sustain the chemical reaction, unless something interrupts the process. 7. Most extinguishers stop the burning by cooling the fuel below its kindling temperature, by cutting off the supply of oxygen, or by combining these two techniques. 8. Some extinguishing agents interrupt the complex system of molecular chain reactions that occur between the heated fuel and the oxygen. B. Cooling the Fuel 1. If the temperature of the fuel falls below its ignition point or kindling temperature, the combustion process will stop. a. Water extinguishes a fire using this method. C. Cutting off the Supply of Oxygen 1. Creating a barrier that interrupts the flow of oxygen to the flames will also extinguish a fire. a. Putting a lid on a pan of burning food is an example of this technique. b. Applying a blanket of foam to the surface of a burning liquid is another example. c. Surrounding the fuel with a layer of carbon dioxide can also cut off the supply of oxygen necessary to sustain the burning process. D. Interrupting the Chain Reactions 1. Some extinguishing agents work by interrupting the molecular chain reactions required to sustain combustion.

15 158 Fire Service Instructor: Principles and Practice, Second Edition VIII. Types of Extinguishing Agents Time: 65 Minutes Slides: Level: Fire Fighter I Lecture/Discussion Slide 35 Extinguishing Agents Substance contained in portable fire extinguisher that puts out a fire Various chemicals are used (including water). Best agent for a particular hazard depends on several factors. Types of materials involved Anticipated size of the fire Slide 36 Types of Extinguishing Agents Water Dry chemicals Carbon dioxide Foam Wet chemicals Halogenated agents Dry powder Slide 37 Water Efficient, plentiful, and inexpensive Converts from liquid to steam Effective on Class A fires Less effective or dangerous on other classes Loaded-stream extinguishers Wetting agents A. Introduction to Types of Extinguishing Agents 1. An extinguishing agent is the substance contained in a portable fire extinguisher that puts out a fire. 2. Various different chemicals, including water, are used in portable fire extinguishers. 3. The best extinguishing agent for a particular hazard depends on several factors, including the types of materials involved and the anticipated size of the fire. 4. Portable fire extinguishers use seven basic types of extinguishing agents: a. Water b. Dry chemicals c. Carbon dioxide d. Foam e. Wet chemicals f. Halogenated agents g. Dry powder B. Water 1. Water is an efficient, plentiful, and inexpensive extinguishing agent. 2. When applied to fire, water converts from liquid into steam, absorbing heat in the process. 3. Water is very effective for extinguishing Class A fires. 4. Many Class A fuels absorb water, which lowers the temperature of the fuel and prevents rekindling. 5. Water is a much less effective extinguishing agent for other fire classes. a. Applying water to hot cooking oil can cause splattering, which can spread the fire and possibly endanger the extinguisher operator. b. Burning flammable liquids will float on top of water. c. Because water conducts electricity, it is dangerous to apply a stream of water to any fire that involves energized electrical equipment. d. If water is applied to a burning combustible metal, a violent reaction can occur. e. Because of these limitations, plain water is only used in Class A fire extinguishers.

16 Chapter 7: Portable Fire Extinguishers 159 Slide 38 Dry Chemical (1 of 3) Stream of finely ground particles Different types of compounds are used. Extinguish in two ways: Interrupts chemical chain reaction Absorbs large quantities of heat Slide 39 Dry Chemical (2 of 3) Several advantages over water extinguishers Ordinary: Suitable for Class B and C fires Multipurpose: Rated for Class A, B, and C fires Slide 40 Dry Chemical (3 of 3) Additives prevent packing and caking. Disadvantage: Chemicals are corrosive. Primary compounds: Sodium bicarbonate Potassium bicarbonate Urea-based potassium carbonate Potassium chloride Ammonium phosphate 6. One disadvantage of water is that it freezes at 32 F (0 C). a. In areas that are subject to freezing, loaded-stream extinguishers can be used. i. These extinguishers combine an alkali metal salt and water. ii. The salt lowers the freezing point of water, so the extinguisher can be used in much colder areas. b. Wetting agents can also be added to the water in a fire extinguisher. i. These agents reduce the surface tension of the water, allowing it to penetrate more effectively into many fuels, such as baled cotton or fibrous materials. C. Dry Chemical 1. Dry chemical fire extinguishers deliver a stream of very finely ground particles onto a fire. 2. Different chemical compounds are used to produce extinguishers of varying capabilities and characteristics. 3. The dry chemical extinguishing agents work in two ways. a. First, the dry chemicals interrupt the chemical chain reactions that occur within the combustion process. b. In addition, the tremendous surface area of the finely ground particles allows them to absorb large quantities of heat. 4. Dry chemical extinguishing agents offer several advantages over water extinguishers: a. They are effective on Class B (flammable liquids and gases) fires. b. They can be used on Class C (energized electrical equipment) fires, because the chemicals are nonconductive. c. They are not subject to freezing. 5. The first dry chemical extinguishers were introduced during the 1950s and were rated only for Class B and C fires. a. The industry term for these B:C-rated units is ordinary dry chemical extinguishers. 6. During the 1960s multipurpose dry chemical extinguishers were introduced. a. These extinguishers are rated for Class A, B, and C fires. b. The chemicals in these extinguishers form a crust over Class A combustible fuels to prevent rekindling. 7. Multipurpose dry chemical extinguishing agents are in the form of fine particles and are treated with other chemicals to help maintain an even flow when the extinguisher is being used. 8. Additional additives prevent them from absorbing moisture, which could cause packing or caking and interfere with the discharge. 9. One disadvantage of dry chemical extinguishers is that the chemicals, particularly the multipurpose dry chemicals, are corrosive and can damage electronic equipment, such as computers, telephones, and copy machines. a. The fine particles are carried by the air and settle like a fine dust inside the equipment. b. Over a period of months, the residue can corrode metal parts, causing considerable damage. 10. If electronic equipment is exposed to multipurpose dry chemical extinguishing agents, it should be cleaned professionally within 48 hours after exposure.

17 160 Fire Service Instructor: Principles and Practice, Second Edition Slide 41 Carbon Dioxide (1 of 3) 1.5 times heavier than air Forms a dense cloud displacing air surrounding the fuel Interrupts combustion by Reducing the oxygen Disrupting liquid fuel s ability to vaporize Slide 42 Carbon Dioxide (2 of 3) Stored under pressure as a liquid Rated for Class B and C fires only Slide 43 Carbon Dioxide (3 of 3) Limitations include: Weight Range Weather Confined spaces Suitability 11. The five primary compounds used as dry chemicals extinguishing agents are: a. Sodium bicarbonate (rated for Class B and C fires only) b. Potassium bicarbonate (rated for Class B and C fires only) c. Urea-based potassium bicarbonate (rated for Class B and C fires only) d. Potassium chloride (rated for Class B and C fires only) e. Ammonium phosphate (rated for Class A, B, and C fires) 12. Although ordinary dry chemical extinguishers can also be used against Class A (common combustibles) fires, a water dousing is also needed to extinguish any smoldering embers and prevent rekindling. 13. Which dry chemical extinguisher to use depends on the compatibility of different agents with each other and with products they might contact. 14. Some dry chemical extinguishing agents cannot be used in combination with particular types of foam. D. Carbon Dioxide 1. CO 2 is a gas that is 1.5 times heavier than air. 2. When carbon dioxide is discharged on a fire, it forms a dense cloud that displaces the air surrounding the fuel. 3. This interrupts the combustion process by reducing the amount of oxygen that can reach the fuel. 4. A blanket of carbon dioxide over the surface of a liquid fuel can also disrupt the fuel s ability to vaporize. 5. In portable fire extinguishers, carbon dioxide is stored under pressure as a liquid. a. It is colorless and odorless. It is discharged through a hose and expelled on the fire through a horn. b. When it is released, the carbon dioxide is very cold and forms a visible cloud of dry ice because moisture in the air will freeze when it comes into contact with the carbon dioxide. 6. Carbon dioxide is rated for Class B and C fires only. 7. It does not conduct electricity and has two significant advantages over dry chemical agents: it is not corrosive and it does not leave any residue. 8. Carbon dioxide also has several limitations and disadvantages. a. Weight: Carbon dioxide extinguishers are heavier than similarly rated extinguishers that use other extinguishing agents. b. Range: Carbon dioxide extinguishers have a short discharge range, which requires the operator to be close to the fire, increasing the risk of personal injury. c. Weather: Carbon dioxide does not perform well at temperatures below 0 F ( 18 C) or in windy or drafty conditions because it dissipates before it reaches the fire. d. Confined spaces: When used in confined areas, carbon dioxide dilutes the oxygen in the air. e. Suitability: Carbon dioxide extinguishers are not suitable for use on fires involving pressurized fuel or on cooking grease fires.

18 Chapter 7: Portable Fire Extinguishers 161 Slide 44 Foam (1 of 2) Water-based foam concentrate solution Nozzles introduce air to form foam blanket. Use on Class A or B fires. Additives depend on compatibility with fuels. Slide 45 Foam (2 of 2) Some foams are approved for polar solvents. Not suitable for Class C fires Cannot be stored or used at freezing temperatures Slide 46 Wet Chemical Only agent to meet Class K fire rating Formulated for use in commercial kitchens Saponification Creates thick blanket to smother the fire and prevent re-ignition Discharged as a fine spray Very effective and easy to clean up E. Foam 1. Foam fire extinguishers discharge a water-based solution with a measured amount of foam concentrate added. 2. The nozzles on foam extinguishers are designed to introduce air into the discharge stream, thus producing a foam blanket. 3. Foam extinguishing agents are formulated for use on either Class A or Class B fires. 4. Class A foam extinguishers for ordinary combustible fires extinguish fires in the same way that water extinguishes fires. a. This type of extinguisher can be produced by adding Class A foam concentrate to the water in a standard, 2.5-gallon, stored-pressure extinguisher. b. The foam concentrate reduces the surface tension of the water, allowing for better penetration into the burning materials. 5. Class B foam extinguishers discharge a foam solution that floats across the surface of a burning liquid and prevents the fuel from vaporizing. a. The foam blanket forms a barrier between the fuel and the oxygen, extinguishing the flames and preventing re-ignition. b. These agents are not suitable for Class B fires that involve pressurized fuels or cooking oils. c. The most common Class B additives are aqueous film-forming foam (AFFF) and film-forming fluoroprotein (FFFP) foam. i. Both concentrates produce very effective foams. ii. Which one should be used depends on the product s compatibility with a particular flammable liquid and other extinguishing agents that could be used on the same fire. d. Some Class B foam extinguishing agents are approved for use on polar solvents, which are water-soluble flammable liquids such as alcohols, acetone, esters, and ketones. i. Only extinguishers that are specifically labeled for use with polar solvents should be used if these products are present. e. Although they are not specifically intended for Class A fires, most Class B foams can also be used on ordinary combustibles. i. The reverse is not true, however; Class A foams are not effective on Class B fires. 6. Foam extinguishers are not suitable for use on Class C fires and cannot be stored or used at freezing temperatures. F. Wet Chemical 1. Wet chemical extinguishers are the only type of extinguisher to qualify under the new Class K rating requirements. 2. They use wet chemical extinguishing agents, which are chemicals applied as water solutions. 3. Before Class K extinguishing agents were developed, most fire extinguishing systems for kitchens used dry chemicals. a. The minimum requirement for a commercial kitchen was a 40-B-rated sodium bicarbonate or potassium bicarbonate extinguisher. b. These systems required extensive clean-up after their use, which often resulted in serious business interruptions. 4. All new fixed extinguishing systems in restaurants and commercial kitchens now use wet chemical extinguishing agents. a. These agents are specifically formulated for use in commercial kitchens and food-product manufacturing facilities, especially where food is cooked in a deep fryer.

19 162 Fire Service Instructor: Principles and Practice, Second Edition Slide 47 Halogenated Agents (1 of 2) Produced from family of liquefied gases Clean agents Twice as effective as carbon dioxide Two categories Halons: Use limited by Montreal Protocol Halocarbons: Replaced halons Slide 48 Halogenated Agents (2 of 2) Stored as liquids and discharged under high pressure Vapor mist disrupts chain reaction. Dissipate in windy conditions Displace oxygen in confined spaces Halon 1211 should rarely be used. Four agents in portable extinguishers b. The fixed systems discharge the agent directly over the cooking surfaces. c. There is no numeric rating of their efficiency in portable fire extinguishers. 5. The Class K wet chemical agents include aqueous solutions of potassium acetate, potassium carbonate, and potassium citrate, either singly or in various combinations. 6. The wet agents convert the fatty acids in cooking oils or fats to a soap or foam, a process known as saponification. 7. When wet chemical agents are applied to burning vegetable oils, they create a thick blanket of foam that quickly smothers the fire and prevents it from reigniting while the hot oil cools. 8. The agents are discharged as a fine spray, which reduces the risk of splattering. 9. They are very effective at extinguishing cooking oil fires, and clean-up afterward is much easier, allowing a business to reopen sooner. G. Halogenated Agents 1. Halogenated extinguishing agents are produced from a family of liquefied gases, known as halogens, that includes fluorine, bromine, iodine, and chlorine. 2. Hundreds of different formulations can be produced from these elements with many different properties and potential uses. 3. Although several of these formulations are very effective for extinguishing fires, only a few of them are commonly used as extinguishing agents. 4. Halogenated extinguishing agents are called clean agents because they leave no residue and are ideally suited for areas that contain computers or sensitive electronic equipment. 5. Per pound, they are approximately twice as effective at extinguishing fires as carbon dioxide. 6. There are two categories of halogenated extinguishing agents: halons and halocarbons. a. A 1987 international agreement, known as the Montreal Protocol, limits halon production because these agents damage the earth s ozone layer. b. Halons have been replaced by a new family of extinguishing agents, halocarbons. 7. The halogenated agents are stored as liquids and are discharged under relatively high pressure. a. They release a mist of vapor and liquid droplets that disrupt the molecular chain reactions within the combustion process to extinguish a fire. b. These agents dissipate rapidly in windy conditions, as does carbon dioxide, so their effectiveness is limited in outdoor locations. c. Because these agents also displace oxygen, they should be used with care in confined areas. 8. Halon 1211 (bromochlorodifluoromethane) should be used judiciously and only in situations where its clean properties are essential, due to its environmental impact. a. Small Halon 1211 extinguishers are rated for Class B and C fires, but are unsuited for use on fires involving pressurized fuels or cooking grease. b. Larger halon extinguishers are also rated for Class A fires. 9. Currently, four types of halocarbon agents are used in portable extinguishers: hydrochlorofluorocarbon (HCFC), hydrofluorocarbon (HFC), perfluorocarbon (PFC), and fluoroiodocarbon (FIC).

20 Chapter 7: Portable Fire Extinguishers 163 Side 49 Dry Powder Used on combustible metal fires (Class D) Stored in granular or powdered form Forms solid crust over burning metal Sodium chloride or graphite powder Avoid splatter. Violent reactions can result from any trace quantities of water. H. Dry Powder 1. Dry powder extinguishing agents are chemical compounds used to extinguish fires involving combustible metals (Class D fires). 2. These agents are stored in fine granular or powdered form and are applied to smother the fire. 3. They form a solid crust over the burning metal to exclude oxygen and absorb heat. 4. The most commonly used dry powder extinguishing agent is formulated from finely ground sodium chloride (table salt) plus additives to help it flow freely over a fire. a. A thermoplastic material mixed with the agent binds the sodium chloride particles into a solid mass when they come into contact with a burning metal. 5. Another dry powder agent is produced from a mixture of finely granulated graphite powder and compounds containing phosphorus. a. This agent cannot be expelled from fire extinguishers; it is produced in bulk form and applied by hand, using a scoop or a shovel. b. When applied to a metal fire, the phosphorus compounds release gases that blanket the fire and cut off its supply of oxygen. c. The graphite absorbs heat from the fire, allowing the metal to cool below its ignition point. 6. Other specialized dry powder extinguishing agents are available for fighting specific types of metal fires. a. For details, see NFPA s Fire Protection Handbook. 7. Class D agents must be applied very carefully so that the molten metal does not splatter. a. No water should come in contact with the burning metal. IX. Fire Extinguisher Design Time: 15 Minutes Slides: Level: Fire Fighter I Lecture/Discussion Slide 50 Fire Extinguisher Design Use pressure to expel contents. Many extinguishers require pressurized gas to expel the agent. Some agents are self-expelling. Hand-operated pumps expel water or water with additives. A. All portable fire extinguishers use pressure to expel their contents onto a fire. 1. Many portable fire extinguishers rely on pressurized gas to expel the extinguishing agent. a. The gas can be stored with the extinguishing agent in the body of the extinguisher, or externally, in a separate cartridge or cylinder. 2. With external storage, the extinguishing agent is put under pressure only as it is used. a. Some extinguishing agents, such as carbon dioxide, are called selfexpelling agents. b. Most of these agents are normally gases, which are stored as liquids under pressure. c. When the confining pressure is released, the agent rapidly expands, causing it to self-discharge. d. Hand-operated pumps are used to expel the agent when water or water with additives is the extinguishing agent.

21 164 Fire Service Instructor: Principles and Practice, Second Edition Slide 51 Portable Fire Extinguisher Components (1 of 7) Most hand-held extinguishers have six basic parts: Cylinder or container Carrying handle Nozzle or horn Trigger Locking mechanism Pressure indicator Slide 52 Portable Fire Extinguisher Components (2 of 7) Cylinder or container Body of the extinguisher Holds the extinguishing agent Nitrogen, compressed air, or carbon dioxide used to pressurize the cylinder Gas can be stored internally (stored-pressure) or externally (cartridge/cylinder). Slide 53 Portable Fire Extinguisher Components (3 of 7) Handle Used to carry an extinguisher and to hold it during use Extinguishers weighing more than 3 lbs must have handles. Usually located just below the trigger mechanism Slide 54 Portable Fire Extinguisher Components (4 of 7) Nozzle or horn Expels agent Attached directly to valve assembly or at the end of a short hose Foam extinguishers have a special aspirating nozzle. B. Portable Fire Extinguisher Components 1. Most hand-held portable fire extinguishers have six basic parts. a. A cylinder or container that holds the extinguishing agent b. A carrying handle c. A nozzle or horn d. A trigger and discharge valve assembly e. A locking mechanism to prevent accidental discharge f. A pressure indicator 2. Cylinder or container a. The body of the extinguisher, known as the cylinder or container, holds the extinguishing agent. b. Nitrogen, compressed air, or carbon dioxide can be used to pressurize the cylinder to expel the agent. c. Stored-pressure extinguishers store both the extinguishing agent, in wet or dry form, and the expeller gas under pressure in the cylinder. d. Cartridge/cylinder extinguishers rely on an external cartridge of pressurized gas, which is only released when the extinguisher is to be used. 3. Handle a. The handle is used to carry a portable fire extinguisher and, in many cases, to hold it during use. b. The actual design of the handle varies from model to model, but all extinguishers that weigh more than 3 lb have handles. c. In many cases, the handle is located just below the trigger mechanism. 4. Nozzle or horn a. The extinguishing agent is expelled through a nozzle or horn. b. In some extinguishers, the nozzle is attached directly to the valve assembly at the top of the extinguisher. c. In other models, the nozzle is at the end of a short hose. d. Foam extinguishers have a special aspirating nozzle that introduces air into the extinguishing agent, creating the foam. e. Carbon dioxide extinguishers have a tubular or conical horn, which is often mounted at the end of a short hose. f. Pump tank extinguishers, which are nonpressurized, manually operated water extinguishers, usually have a nozzle at the end of a short hose.

22 Chapter 7: Portable Fire Extinguishers 165 Slide 55 Portable Fire Extinguisher Components (5 of 7) Trigger Mechanism that is squeezed or depressed to discharge extinguishing agent Usually a lever located above the handle Cartridge/cylinder models usually have a two-step operating sequence. Slide 56 Portable Fire Extinguisher Components (6 of 7) Locking mechanism Prevents accidental discharge Simplest form is a stiff pin Inserted through a hole in the trigger Usually has a ring at the end Tamper seal Secures the pin Discourages people from tinkering with extinguisher Slide 57 Portable Fire Extinguisher Components (7 of 7) Pressure indicator Shows whether a stored-pressure extinguisher has sufficient pressure to operate Most extinguishers use a needle gauge. Some disposable extinguishers have a pin that, when pressed, tests the pressure. Slide 58 Wheeled Fire Extinguishers Large units mounted on wheeled carriages Typically contain 150 to 350 lbs Indoor use requires wide doors and aisles. Long delivery hoses allow operators to attack fire from multiple sides. Usually pressurized by separate cylinders Installed in special hazard areas 5. Trigger a. The trigger is the mechanism that is squeezed or depressed to discharge the extinguishing agent. b. In some models, the trigger is a button positioned just above the handle. c. Most of the time, however, the trigger is a lever located above the handle. d. The operator lifts the extinguisher by the handle and simultaneously squeezes down on the discharge lever. e. Cartridge/cylinder extinguisher models usually have a two-step operating sequence. i. First, a handle or lever is pushed to pressurize the stored agent. ii. Then a trigger-type mechanism incorporated in the nozzle assembly is used to control the discharge. 6. Locking mechanism a. The locking mechanism is a simple quick-release device that prevents accidental discharge of the extinguishing agent. b. The simplest form of locking mechanism is a stiff pin, which is inserted through a hole in the trigger to prevent it from being depressed. c. The pin usually has a ring at the end so that it can be removed quickly. d. A special plastic tie, called a tamper seal, is used to secure the pin. e. The tamper seal is designed to break easily when the pin is pulled. f. Removing the pin and tamper seal is best accomplished with a twisting motion. g. The tamper seal makes it easy to see whether the extinguisher has been used and not recharged. h. The seal also discourages people from playing or tinkering with the extinguisher. 7. Pressure indicator a. The pressure indicator or gauge shows whether a stored-pressure extinguisher has sufficient pressure to operate properly. b. Over time, the pressure in an extinguisher may dissipate. c. Checking the gauge first will tell you whether the extinguisher is ready for use. d. Pressure indicators vary in design and sophistication. e. Most extinguishers use a needle gauge. Pressure may be shown in pounds per square inch (psi) or on a three-step scale (too low, proper range, too high). f. Pressure gauges are usually color-coded; a green area indicates the proper pressure zone. g. Some disposable fire extinguishers intended for home use have an even simpler pressure indicator. 8. Wheeled fire extinguishers a. Wheeled fire extinguishers are large units mounted on wheeled carriages. b. Wheeled extinguishers typically contain between 150 and 350 lb of extinguishing agent. c. The wheeled design lets one person transport the extinguisher to the fire. d. If a wheeled extinguisher is intended for indoor use, doorways and aisles must be wide enough to allow passage to every area where it could be needed. e. Wheeled fire extinguishers usually have long delivery hoses, so the unit can stay in one spot as the operator moves around to attack the fire from more than one side. f. Usually, a separate cylinder containing nitrogen or some other compressed gas provides the pressure necessary to operate the extinguisher. g. Wheeled fire extinguishers are most often installed in special hazard areas.

23 166 Fire Service Instructor: Principles and Practice, Second Edition X. Fire Extinguisher Characteristics Time: 40 Minutes Slides: Level: Fire Fighter I Lecture/Discussion Slide 59 Fire Extinguisher Characteristics (1 of 2) Portable extinguishers vary according to Extinguishing agent Capacity Effective range Time it takes to completely discharge agent Extinguishers also have different mechanical designs. Slide 60 Fire Extinguisher Characteristics (2 of 2) Seven types of extinguishers: Water Dry chemical Carbon dioxide Class B foam Wet chemical Halogenated agent Dry powder Slide 61 Water Extinguishers (1 of 6) Used to cool burning fuel below its ignition temperature Intended primarily for Class A fires Slide 62 Water Extinguishers (2 of 6) Stored-pressure water-type Used for incipient Class A fires Contents can freeze Can be recharged at any location that provides water and a source of compressed air A. Introduction to Fire Extinguisher Characteristics 1. Portable fire extinguishers vary according to their extinguishing agent, capacity, effective range, and the time it takes to completely discharge their agent. 2. They also have different mechanical designs. 3. The seven types of extinguishers described include: a. Water extinguishers b. Dry chemical extinguishers c. Carbon dioxide extinguishers d. Class B foam extinguishers e. Halogenated-agent extinguishers f. Dry powder extinguishing agents g. Wet chemical extinguishers B. Water Extinguishers 1. Water extinguishers are used to cool the burning fuel below its ignition temperature. a. Water extinguishers are intended for use primarily on Class A (common combustibles) fires. b. Class B foam extinguishers, which are a specific type of water extinguisher, are intended for flammable liquids fires. c. Water extinguishers include stored-pressure, loaded-stream, and wettingagent models. 2. Stored-pressure water type-extinguisher a. The most popular kind of stored-pressure water-type extinguisher is the 2.5-gallon model with a 2-A rating. b. Many fire department vehicles carry this type of fire extinguisher for use on incipient Class A fires. c. This extinguisher expels water in a solid stream with a range of 35 to 40 through a nozzle at the end of a short hose. d. The discharge time is approximately 55 seconds if the extinguisher is used continuously. e. A full extinguisher weighs about 30 lbs.

24 Chapter 7: Portable Fire Extinguishers 167 Slide 63 Water Extinguishers (3 of 6) Loaded-stream water-type Discharge solution of water containing an alkali metal salt Usable to 40 F Most common model is 2.5 gallon unit. Larger units are pressurized by separate cylinder of carbon dioxide. Slide 64 Water Extinguishers (4 of 6) Wetting agent, Class A foam water-type Solution reduces surface tension. Allows water to penetrate Class A Foam concentrate reduces surface tension and creates foam. Configurations same as hand-held and wheeled models Do not expose to temperatures below 40 F. f. Because the contents of these extinguishers can freeze, they should not be installed in areas where the temperature is expected to drop below 32 F (0 C). i. Antifreeze models of stored-pressure water-type extinguishers, called loaded-stream extinguishers, are available. ii. The loaded-stream agent will not freeze at temperatures as low as 40 F ( 40 C). g. The recommended procedure for operating a stored-pressure water extinguisher i. Set it on the ground, grasp the handle with one hand, and pull out the ring pin or release the locking latch with the other hand. ii. The extinguisher can be lifted and used to douse the fire. iii. Use one hand to aim the stream at the fire, and squeeze the trigger with the other hand. iv. The stream of water can be made into a spray by putting a thumb at the end of the nozzle; this technique is often used after the flames have been extinguished to thoroughly soak the fuel. h. Stored-pressure water-type extinguishers can be recharged at any location that provides water and a source of compressed air. i. Follow the manufacturer s instructions to ensure proper and safe recharging. 3. Loaded-stream water-type extinguishers a. Discharge a solution of water containing an alkali metal salt that prevents freezing at temperatures as low as 40 F ( 40 C). b. The most common model is the 2.5-gallon unit, which is identical to a typical stored-pressure water extinguisher. c. Hand-held models are available with capacities of 1 to 2.5 gallons of water and are rated from 1-A to 3-A. d. Larger units, including a 17-gallon unit rated 10-A and a 33-gallon unit rated 20-A, are also available. e. Pressure for these extinguishers is supplied by a separate cylinder of carbon dioxide. 4. Wetting-agent and class A foam water-type extinguishers a. Wetting-agent and water-type extinguishers expel water that contains a solution to reduce its surface tension (the physical property that causes water to bead or form a puddle on a flat surface). b. Reducing the surface tension allows water to spread over the fire and penetrate more efficiently into Class A fuels. c. Class A foam extinguishers contain a solution of water and Class A foam concentrate. d. Both wetting-agent and Class A foam extinguishers are available in the same configurations as water extinguishers, including hand-held storedpressure models and wheeled units. e. These extinguishers should not be exposed to temperatures below 40 F (4 C). Slide 65 Water Extinguishers (5 of 6) Pump-tank water-type Range from 1-A rated, 1.5-gallon units, to 4-A rated, 5-gallon units Nonpressurized storage Expelled via hand-operated piston pump Sits upright on the ground Can be used with antifreeze solution 5. Pump tank water-type extinguishers a. Pump tank water-type extinguishers come in sizes ranging from 1-A rated, 1.5-gallon units to 4-A rated, 5-gallon units. b. The water in these units is not stored under pressure. c. The pressure to expel the water is provided by a hand-operated, doubleacting, vertical piston pump, which moves water out through a short hose on both the up and the down strokes. d. This type of extinguisher sits upright on the ground during use. e. A small bracket at the bottom allows the operator to steady the extinguisher with one foot while pumping. f. Pump tank extinguishers can be used with antifreeze.

25 168 Fire Service Instructor: Principles and Practice, Second Edition Slide 66 Water Extinguishers (6 of 6) Backpack water-type Used primarily for brush and grass fires Water tank made of fiberglass, stainless or galvanized steel, or brass Wide mouth opening with filter allows easy refill. Slide 67 Dry Chemical Extinguishers (1 of 4) Contain variety of agents in granular form Ordinary models extinguish Class A and B fires. Multipurpose models extinguish Class A, B, and C fires. All can be used on Class C fires, but residue damages electronics. g. The manufacturer should be consulted for details because some types of antifreeze (such as common salt) can corrode the extinguisher or damage the pump. i. Extinguishers with steel shells corrode more easily than those with copper or nonmetallic shells. 6. Backpack water-type extinguishers a. Backpack water-type extinguishers are used primarily outdoors for fighting brush and grass fires. b. Most of these units have a tank capacity of 5 gallons and weigh about 50 lb when full. c. Backpack extinguishers are listed by Underwriters Laboratories but do not carry numeric ratings. d. The water tank can be made of fiberglass, stainless steel, galvanized steel, or brass. e. Backpack extinguishers are designed to refill easily in the field, from a lake or a stream, through a wide-mouth opening at the top. f. A filter keeps dirt, stones, and other contaminates from entering the tank. g. Antifreeze agents, wetting agents, or other special water-based extinguishing agents can be used with backpack water-type extinguishers. h. Most backpack extinguishers have hand pumps. i. The most common design has a trombone-type double-acting piston pump located at the nozzle, which is attached to the tank by a short rubber hose. i. The operator holds the pump in both hands and moves the piston back and forth. j. Some models have a compression pump built into the side of the tank. i. It takes about ten strokes of the pump handle to build the initial pressure, which is maintained through continuous slow strokes. ii. The operator uses the other hand to control the discharge. iii. A lever-operated shut-off nozzle is provided at the end of a short hose. C. Dry Chemical Extinguishers 1. Contain a variety of chemical extinguishing agents in granular form a. Hand-held dry chemical extinguishers are available with capacities ranging from 1 to 30 lb of agent. b. Wheeled fire extinguishers are available with capacities up to 350 lb of agent. c. Ordinary dry chemical models can be used to extinguish Class B and C fires. d. Multipurpose dry chemical models are rated for use on Class A, B, and C fires. e. All dry chemical extinguishing agents can be used on Class C fires that involve energized electrical equipment; however, the residue left by the dry chemical can be very damaging to computers, electronic devices, and electrical equipment. f. Stored-pressure units expel the dry chemical agent in the same manner as a stored-pressure water extinguisher. g. The dry chemical agent in a cartridge/cylinder extinguisher is not stored under pressure.

26 Chapter 7: Portable Fire Extinguishers 169 Slide 68 Dry Chemical Extinguishers (2 of 4) Discharge time is 8 to 20 seconds in small models, up to 30 seconds in larger units. Range of discharge is from 5 to 30, depending on size. Trigger allows intermittent discharge. Extinguishers do not retain internal pressure for extended periods. Slide 69 Dry Chemical Extinguishers (3 of 4) Disposable models not refillable Can be stored at temperatures below freezing Ordinary Available in hand-held models up to 160-B:C Wheeled units carry up to 640-B:C. Slide 70 Dry Chemical Extinguishers (4 of 4) Multipurpose Aluminum phosphate agent Hand-held models 1-A to 20-A, 10-B:C to 120-B:C Large wheeled units 20-A to 40-A, 60-B:C to 320 B:C Should never be used for Class K fires Slide 71 Carbon Dioxide Extinguishers (1 of 3) Rated for Class B and C fires Extinguishes by enveloping fuel in a cloud of inert gas Also cools the burning material 1.5 times heavier than air Colorless, odorless, nonconductive, and inert h. Most small, hand-held dry chemical extinguishers are designed to discharge completely in as few as 8 to 20 seconds. i. Depending on the extinguisher s size, the horizontal range of the discharge stream can be from 5 to 30. j. The trigger allows the extinguisher to be discharged intermittently, starting and stopping the agent flow. k. Anytime a dry chemical extinguisher has been activated or partially used, the extinguisher must be serviced and recharged to replenish the extinguishing agent and restore the unit s pressure. l. Dry chemical fire extinguishers can be stored and used in areas with temperatures below freezing. 2. Ordinary dry chemical extinguishers a. Available in hand-held models with ratings up to 160-B:C. b. Larger, wheeled units carry ratings up to 640-B:C. 3. Multipurpose dry chemical extinguishers a. Ammonium phosphate is commonly called a multipurpose dry chemical agent because it can be used on Class A, B, and C fires. b. Multipurpose dry chemical extinguishers are available in hand-held models with ratings ranging from 1-A to 20-A and from 10-B:C to 120-B:C. c. Larger, wheeled models have ratings ranging from 20-A to 40-A and from 60-B:C to 320-B:C. d. Multipurpose dry chemical extinguishers should never be used on cooking oil (Class K) fires. i. The ammonium phosphate-based extinguishing agent is acidic and will not react with cooking oils to produce the smothering foam needed to extinguish the fire. ii. Worse, the acid will counteract the foam-forming properties of any alkaline extinguishing agent that is applied to the same fire. D. Carbon Dioxide Fire Extinguishers 1. Rated to fight Class B and C fires a. Carbon dioxide extinguishes a fire by enveloping the fuel in a cloud of inert gas, which reduces the oxygen content of the surrounding atmosphere and smothers the flames. b. Because the carbon dioxide discharge is very cold, it also helps to cool the burning materials and surrounding areas. 2. Carbon dioxide gas is 1.5 times heavier than air, colorless, odorless, non-conductive, and inert.

27 170 Fire Service Instructor: Principles and Practice, Second Edition Slide 72 Carbon Dioxide Extinguishers (2 of 3) Is noncorrosive Both an expelling agent and an extinguishing agent Have relatively short discharge ranges Not recommended outdoors or near strong air currents Slide 73 Carbon Dioxide Extinguishers (3 of 3) Trigger mechanism allows intermittent operation. Metal horns no longer made, but some units may still be in service and are not compatible for Class C fires. Slide 74 Class B Foam Extinguishers Aspirating nozzle discharges solution of water and AFFF or FFFP agent. Discharged through an aspirating nozzle Foam blanket floats over surface of liquid. Effective for Class A and B fires, but not suitable for Class C or K fires Not effective at freezing temperatures 3. It is also noncorrosive and does not leave any residue. 4. Carbon dioxide is both an expelling agent and an extinguishing agent. a. The agent is stored under a pressure of 823 lb psi, which keeps the carbon dioxide in liquid form at room temperatures. b. When the pressure is released, the liquid carbon dioxide rapidly converts to a gas. c. The expanding gas forces the agent out of the container. d. The carbon dioxide is discharged through a siphon tube that reaches to the bottom part of the storage cylinder. e. It is forced through a hose to a horn or cone-shaped applicator that is used to direct the flow of the agent. f. When discharged, the agent is very cold and contains a mixture of carbon dioxide gas and solid carbon dioxide, which quickly converts to gas. 5. Compared to other types of extinguishers, carbon dioxide extinguishers have relatively short discharge ranges, 3 to Depending on size, carbon dioxide extinguishers can discharge completely in 8 to 30 seconds. 7. Carbon dioxide fire extinguishers are not recommended for outdoor use or for locations with strong air currents. 8. Carbon dioxide extinguishers have a trigger mechanism that can be operated intermittently to preserve the remaining agent. a. The pressurized carbon dioxide will remain in the extinguisher, but the extinguisher will have to be recharged after use. b. The extinguisher is weighed to determine how much agent is left in the storage cylinder. 9. The smaller carbon dioxide extinguishers contain from 2 to 5 lb of agent. a. These units are designed to be operated with one hand. b. The horn is attached directly to the discharge valve on the top of the extinguisher by a hinged metal tube. c. In larger models, the horn is attached at the end of a short hose. d. These models require two-handed operation. 10. The horns of some older carbon dioxide fire extinguishers were constructed of metal, which conducts electricity. a. These extinguishers do not carry a Class C rating and must not be used around fires involving energized electrical equipment. b. Metal horns are no longer made for carbon dioxide fire extinguishers, but some of these units may still be in service. E. Class B Foam Extinguishers 1. Very similar in appearance and operation to water extinguishers a. Instead of plain water they discharge a solution of water and either AFFF or FFFP foam concentrate. b. The agent is discharged through an aspirating nozzle, which mixes air into the stream. c. They create a foam blanket that will float over the surface of a flammable liquid. 2. Class B foam agents are also very effective in fighting Class A fires. a. They are not suitable for Class C fires or for fires involving flammable liquids or gases under pressure. b. They are not intended for use on cooking oil fires, and only certain foam extinguishers can be used on fires involving polar solvents. c. Detailed information on the use of AFFF and FFFP is available in NFPA Standard 11.

28 Chapter 7: Portable Fire Extinguishers 171 Slide 75 Wet Chemical Extinguishers Used to protect Class K installations Cooking oils, deep fryers, and grills Commercial facilities use fixed, automatic systems. Portable extinguishers available in 1.5-gallon and 2.5-gallon sizes No numerical ratings Slide 76 Halogenated-Agent Extinguishers Include both halon and halocarbon agents Use of halon agents is strictly controlled due to environmental hazards. Available in hand-held models rated for Class B and C fires Agent discharged as a streaming liquid They are nonconductive and leave no residue. Slide 77 Dry Powder Extinguishing Agents (1 of 2) For Class D fires involving combustible metals Agents and techniques vary. Each agent listed for use on specific combustible metal fires 3. AFFF and FFFP hand-held stored-pressure extinguishers are available in two sizes: 1.6 gallons, rated 2-A:10-B, and 2.5 gallons, rated 3-A:20-B. 4. A wheeled model with a 33 gallons capacity is rated 20-A:160-B. 5. Foam extinguishing agents are not effective at freezing temperatures. F. Wet Chemical Extinguishers 1. Used to protect Class K installations, which include cooking oils, deep fryers, and grills a. Many commercial cooking installations use fixed, automatic fire extinguishing systems as their first line of defense. b. Portable Class K wet chemical extinguishers are currently available in two sizes, 1.5 gallons and 2.5 gallons. c. There are no numerical ratings for these extinguishers. G. Halogenated-Agent Extinguishers 1. Include both halon agents and halocarbon agents. a. Because halon agents can destroy the earth s protective ozone layer, their use is strictly controlled. b. The halocarbons are not subject to the same environmental restrictions. c. Both types of agents are available in hand-held extinguishers rated for Class B and C fires. d. Larger capacity models are also rated for use on Class A fires. 2. The agent is discharged as a streaming liquid, which can be directed at the base of a fire. 3. The discharges from these extinguishers have a horizontal stream range of 9 to The halogenated agents are nonconductive and leave no residue that can damage electrical equipment. 5. These agents are relatively expensive but they perform better than carbon dioxide models in most applications, particularly in windy conditions. 6. Halon 1211 (bromochlorodifluoromethane) is available in hand-held storedpressure extinguishers with capacities that range from 1 lb, rated 1-B:C, to 22 lb, rated 4-A:80-B:C. a. Wheeled Halon 1211 models are available with capacities up to 150 lb with a rating of 30-A:160-B:C. b. The wheeled fire extinguishers use a nitrogen booster charge from an auxiliary cylinder to expel the agent. H. Dry Powder Extinguishing Agents 1. Intended for fighting Class D fires involving combustible metals. a. The extinguishing agents and the techniques required to extinguish Class D fires vary greatly, and depend on the specific fuel, the quantity involved, and the physical form of the fuel, such as grindings, shavings, or solid objects. b. The agent and the application method must be suited to the particular situation. c. Each dry powder extinguishing agent is listed for use on specific combustible metal fires. d. This information and recommended application methods are printed on the container. e. Consult the manufacturer s recommendations for information about Class D agents and extinguishers, as well as NFPA s Fire Protection Handbook.

29 172 Fire Service Instructor: Principles and Practice, Second Edition Slide 78 Dry Powder Extinguishing Agents (2 of 2) Dry powder fire extinguishers Have adjustable nozzles that allow operator to vary the flow of agent Bulk dry powder agents Available in 40 lb and 50 lb pails and 350 lb drums Applied manually using a shovel or scoop 2. Dry powder fire extinguishers a. Sodium chloride-based agents are available with 30 lb capacity in either stored-pressure or cylinder/cartridge models. b. Wheeled models are available with 150 lb and 350 lb capacities. c. Dry powder extinguishers have adjustable nozzles that allow the operator to vary the flow of the extinguishing agent. d. When the nozzle is fully opened, the hand-held models have a range of 6 to 8. e. Extension wand applicators are available to direct the discharge from a more distant position. 3. Bulk dry powder agents a. Available in 40 lb and 50 lb pails and 350 lb drums b. The same sodium chloride-based agent that is used in portable fire extinguishers can be stored in bulk form and applied by hand. c. Another dry powder extinguishing agent for Class D fires, graded granular graphite mixed with compounds containing phosphorus, cannot be expelled from a portable fire extinguisher. d. This agent must be applied manually from a pail or other container using a shovel or scoop. XI. Use of Fire Extinguishers Time: 50 Minutes Slides: Level: Fire Fighter I Lecture/Discussion/Demonstration Slide 79 Use of Fire Extinguishers Six basic steps for extinguishing fires: Locate the fire. Select the proper extinguisher. Transport the extinguisher to the fire. Activate the extinguisher to release the agent. Apply the extinguishing agent. Ensure personal safety. Practice and training are essential. A. Fire extinguishers should be simple to operate. 1. An individual with only basic training should be able to use most fire extinguishers safely and effectively. 2. Every portable extinguisher should be labeled with printed operating instructions. 3. There are six basic steps in extinguishing a fire with a portable fire extinguisher. They are: a. Locate the fire extinguisher. b. Select the proper classification of extinguisher. c. Transport the extinguisher to the location of the fire. d. Activate the extinguisher to release the extinguishing agent. e. Apply the extinguishing agent to the fire for maximum effect. f. Ensure your personal safety by having an exit route. 4. Although these steps are not complicated, practice and training are essential for effective fire suppression. 5. Tests have shown that the effective use of Class B portable fire extinguishers depends heavily on user training and expertise. a. A trained expert can extinguish a fire up to twice as large as a non-expert can, using the same extinguisher. 6. As a fire fighter, you should be able to operate any fire extinguisher that you might be required to use, whether it is carried on your fire apparatus, hanging on the wall of your firehouse, or placed in some other location.

30 Chapter 7: Portable Fire Extinguishers 173 Slide 80 Locating a Fire Extinguisher Know the types and locations of extinguisher on apparatus. Know where extinguishers are located in and around the fire station. Have at least one extinguisher in your home and another in your personal vehicle. Slide 81 Selecting the Proper Extinguisher Requires an understanding of the classification and rating system Fire fighters must quickly determine if a fire can be controlled by an extinguisher. Fire fighters should also determine the appropriate type of extinguisher to place in a given area. Slide 82 Transporting a Fire Extinguisher Best method depends on size, weight, and design of extinguisher. Carry fixed nozzle units in stronger hand. Use weaker hand for units with a hose between trigger and nozzle. Place heavier extinguishers on ground near fire; one hand to depress trigger, one hand to hold nozzle and direct stream. B. Locating a Fire Extinguisher 1. Fire fighters should know what types of fire extinguishers are carried on department apparatus and where each type of extinguisher is located. 2. You should also know where fire extinguishers are located in and around the fire station and other work places. 3. You should have at least one fire extinguisher in your home and another in your personal vehicle and you should know exactly where they are located. C. Selecting the Proper Fire Extinguisher 1. This requires an understanding of the classification and rating system for fire extinguishers. 2. Knowing the different types of agents, how they work, the ratings of the fire extinguishers carried on your fire apparatus, and which extinguisher is appropriate for a particular fire situation is also important. 3. Fire fighters should be able to assess a fire quickly, determine if the fire can be controlled by an extinguisher, and identify the appropriate extinguisher. a. Using an extinguisher with an insufficient rating may not completely extinguish the fire, which can place the operator in danger of being burned or otherwise injured. b. If the fire is too large for the extinguisher, you will have to consider other options such as obtaining additional extinguishers or making sure that a charged hose line is ready to provide back-up. 4. Fire fighters should also be able to determine the most appropriate type of fire extinguisher to place in a given area, based on the types of fires that could occur and the hazards that are present. a. In some cases, one type of extinguisher might be preferred over another. D. Transporting a Fire Extinguisher 1. The best method of transporting a hand-held portable fire extinguisher depends on the size, weight, and design of the extinguisher. 2. Hand-held portable fire extinguishers can weigh as little as 1 lb to as much as 50 lbs. 3. Extinguishers with a fixed nozzle should be carried in the favored or stronger hand. a. This enables the operator to depress the trigger and direct the discharge easily. 4. Extinguishers that have a hose between the trigger and the nozzle should be carried in the weaker or less-favored hand so that the favored hand can grip and aim the nozzle. 5. Heavier extinguishers may have to be carried as close as possible to the fire and placed upright on the ground. a. The operator can depress the trigger with one hand, while holding the nozzle and directing the stream with the other hand. 6. Transporting a fire extinguisher will be practiced in Skill Drill 7-1.

31 174 Fire Service Instructor: Principles and Practice, Second Edition Slide 83 Basic Steps of Fire Extinguisher Operation P-A-S-S acronym: Pull the safety pin. Aim the nozzle at the base of the flames. Squeeze the trigger to discharge agent. Sweep the nozzle across the base of the flames. Practice discharging different types of extinguishers. Slide 84 Ensure Your Personal Safety Approach fire with an exit behind you. Have a planned escape route. Never let fire get between you and exit. Never turn your back on the fire. Watch fire for rekindle. Wear appropriate PPE and SCBA. E. Basic Steps of Fire Extinguisher Operation 1. Activating a fire extinguisher to apply the extinguishing agent is a single operation in four steps. 2. The P-A-S-S acronym is a helpful way to remember these steps: a. Pull the safety pin. b. Aim the nozzle at the base of the flames. c. Squeeze the trigger to discharge the agent. d. Sweep the nozzle across the base of the flames. 3. Most fire extinguishers have very simple operation systems. 4. Practice discharging different types of extinguishers in training situations to build confidence in your ability to use them properly and effectively. F. Ensure Your Personal Safety 1. When using a fire extinguisher, always approach the fire with an exit behind you. a. If the fire suddenly expands or the extinguisher fails to control it, you must have a planned escape route. b. Never let the fire get between you and a safe exit. After suppressing a fire, do not turn your back on it. c. Always watch and be prepared for a rekindle until the fire has been fully overhauled. 2. As a fire fighter, you should wear your personal protective clothing and use appropriate personal protective equipment (PPE). 3. If you must enter an enclosed area where an extinguisher has been discharged, wear full PPE and use SCBA. a. The atmosphere within the enclosed area will probably contain a mixture of combustion products and extinguishing agents. b. The oxygen content within the space may be dangerously depleted. 4. Operating fire extinguishers will be practiced in Skill Drills 7-2 through 7-9. XII. The Care of Fire Extinguishers: Inspection, Maintenance, Recharging, and Hydrostatic Testing Time: 15 Minutes Slides: Level: Fire Fighter I Lecture/Discussion Slide 85 Care of Fire Extinguishers Extinguishers must be regularly inspected and properly maintained. Records keep inspections and maintenance on schedule. Proper training required for inspection and maintenance. Follow manufacturer s recommendations. A. Introduction to the Care of Fire Extinguishers 1. Fire extinguishers must be regularly inspected and properly maintained so they are available for use in an emergency. 2. Records must be kept to ensure that the required inspections and maintenance have been performed on schedule. 3. The individuals assigned to perform these functions must be properly trained and must always follow the manufacturer s recommendations for inspecting, maintaining, recharging, and testing the equipment.

32 Chapter 7: Portable Fire Extinguishers 175 Slide 86 Inspection (1 of 2) Quick check verifies availability for immediate use. Check extinguishers on apparatus regularly. Check tamper seals. Weigh or heft to determine fullness. Examine for obvious physical damage, corrosion, or leaks. Slide 87 Inspection (2 of 2) Check pressure gauge. Confirm proper identification by type and rating. Shake dry chemicals to mix agent. Check nozzle for damage or obstructions. Take problem units out of service and replace with spares. Slide 88 Maintenance Maintenance includes internal inspections and repairs. Maintenance must be performed periodically. An inspection may reveal the need for maintenance. Only qualified personnel can perform maintenance. Slide 89 Common Indicators of Need for Maintenance (1 of 2) Pressure gauge reads outside normal range Out-of-date inspection tag Broken tamper seal Any indication that unit is not full B. Inspection 1. According to NFPA Standard 10, an inspection is a quick check to verify that a fire extinguisher is available and ready for immediate use. 2. Fire extinguishers on fire apparatus should be inspected as part of the regular equipment checks mandated by your department. 3. The fire fighter charged with inspecting the extinguishers should: a. Ensure that tamper seals are intact. b. Determine fullness by weighing or hefting the extinguisher. c. Examine all parts for signs of physical damage, corrosion, or leakage. d. Check the pressure gauge to be sure it is in the operable range. e. Ensure that the extinguisher is properly identified by type and rating. f. Shake dry chemical extinguishers to mix or redistribute the agent. g. Check the nozzle for damage or obstruction by foreign objects. 4. If an inspection reveals any problems, the extinguisher should be removed from service until the required maintenance procedures are performed. 5. The pressure gauge on a stored-pressure extinguisher indicates whether the pressure is sufficient to expel the entire agent. 6. The weight of the extinguisher and the presence of an intact tamper seal should indicate that it is full of extinguishing agent. C. Maintenance 1. The maintenance requirements and intervals for various types of fire extinguishers are outlined in NFPA Standard 10. a. Maintenance includes an internal inspection as well as any repairs that may be required. b. Maintenance procedures must be performed periodically, depending on the type of extinguisher. c. An inspection may also reveal the need to perform maintenance procedures. 2. Maintenance procedures must always be performed by a qualified person. 3. Common indications that an extinguisher needs maintenance include: a. The pressure gauge reading is outside the normal range. b. The inspection tag is out of date. c. The tamper seal is broken, especially in extinguishers with no pressure gauge. d. There is any indication that the extinguisher is not full of extinguishing agent. Slide 90 Common Indicators of Need for Maintenance (2 of 2) Obstruction of hose and/or nozzle assembly Signs of physical damage, corrosion, or rust Visible signs of leakage around discharge valve or nozzle assembly e. The hose and/or nozzle assembly is obstructed. f. There are signs of physical damage, corrosion, or rust. g. Signs of leakage around the discharge valve or nozzle assembly can be seen.

33 176 Fire Service Instructor: Principles and Practice, Second Edition Slide 91 Recharge (1 of 2) Required after every use Take extinguisher out of service immediately after use. Replace only when properly recharged. Extinguishing agent refilled Expulsion agent recharged Tamper seal installed after recharging Slide 92 Recharge (2 of 2) Recharging stored-pressure water extinguishers Can be performed by fire fighters Discharge remaining stored pressure. Add water to water-level indicator. Replace valve assembly. Introduce compressed air to raise pressure to level indicated on gauge. Slide 93 Hydrostatic Testing (1 of 2) Measures extinguisher s ability to withstand internal pressure Special test facility required Above-normal pressure applied to waterfilled cylinder Assigned maximum interval usually 5 or 12 years, depending on vessel type Slide 94 Hydrostatic Testing (2 of 2) Must indicate most recent test on the outside of the extinguisher Extinguisher may not be refilled if most recent test date is not within prescribed limit. All out of date extinguishers must be tested at an appropriate facility. D. Recharging 1. A fire extinguisher must be recharged after each and every use, even if it was not completely discharged. a. The only exceptions are non-rechargeable extinguishers, which should be replaced after any use. b. All performance standards assume that an extinguisher will be fully charged when it has to be used. c. Immediately after any use, an extinguisher should be taken out of service until it has been properly recharged. d. This also applies to any extinguisher that leaks or has a pressure gauge reading above or below the proper operating range. 2. When an extinguisher is recharged, the extinguishing agent is refilled and the system that is provided to expel the agent is fully charged. a. Both the quantity of the agent and the pressurization must be verified. b. A tamper seal is installed after recharging. 3. Typical 2.5-gallon stored-pressure water extinguishers can be recharged by fire fighters using water and a source of compressed air. a. Before the extinguisher is refilled, all remaining stored pressure must be discharged so that the valve assembly can be safely removed. b. Water is added up to the water-level indicator and the valve assembly is replaced. c. Compressed air is then introduced to raise the pressure to the level indicated on the gauge. E. Hydrostatic Testing 1. Most fire extinguishers are pressure vessels, designed to hold a steady internal pressure. a. The ability of an extinguisher to withstand this internal pressure is measured by periodic hydrostatic testing. b. The hydrostatic testing requirements for fire extinguishers are established by the U.S. Department of Transportation and can be found in NFPA Standard 10. c. The test is conducted in a special test facility and involves filling the extinguisher with water and applying above-normal pressure. 2. Each extinguisher has an assigned maximum interval between hydrostatic tests, usually 5 or 12 years, depending on the construction material and vessel type. a. The date of the most recent hydrostatic test must be indicated on the outside of the extinguisher. b. An extinguisher may not be refilled if the date of the most recent hydrostatic test is not within the prescribed limit. c. Any extinguisher that is out of date should be removed from service and sent to the appropriate maintenance facility for hydrostatic testing.

34 Chapter 7: Portable Fire Extinguishers 177 XIII. Summary Time: 15 Minutes Slides: Level: Fire Fighter I Lecture/Discussion Slice 95 Summary (1 of 3) Two main uses of fire extinguishers: To control incipient fires To apply special extinguishing agents Fires and fire extinguishers are grouped by their characteristics. Fire extinguishers are classified and rated based on their characteristics and capabilities. Slide 96 Summary (2 of 3) Two key factors to determine type of extinguisher to place in each area: Class of fire that is likely to occur Magnitude of an incipient fire Best agent for a hazard based on several factors Seven basic types of extinguishing agents Slide 97 Summary (3 of 3) Extinguishers vary by Extinguishing agent Capacity Effective range Time it takes to discharge the agent Six basic steps to using an extinguisher Extinguishers require regular inspection and maintenance. A. Portable fire extinguishers have two primary uses: to extinguish incipient fires (those that have not spread beyond the area of origin), and to control fires where traditional methods of fire suppression are not recommended. B. Fires and fire extinguishers are grouped into classes according to their characteristics. C. Portable fire extinguishers are classified and rated based on their characteristics and capabilities. D. Fire extinguishers that have been tested and approved by an independent laboratory are labeled to clearly designate the class or classes of fire the unit is capable of extinguishing safely. E. Two key factors must be considered when determining which type of extinguisher should be placed in each area: the class of fire that is likely to occur and the potential magnitude of an incipient fire. F. The best extinguishing agent for a particular hazard depends on several factors, including the types of materials involved and the anticipated size of the fire. G. Portable fire extinguishers use seven basic types of extinguishing agents. H. Most hand-held portable fire extinguishers have six basic parts. I. Portable fire extinguishers vary according to their extinguishing agent, capacity, effective range, and the time it takes to completely discharge their agent. J. There are six basic steps in extinguishing a fire with a portable fire extinguisher. K. Fire extinguishers must be regularly inspected and properly maintained so they are available for use in an emergency.

35 178 Fire Service Instructor: Principles and Practice, Second Edition XIV. Skill Drills Time: 135 Minutes Level: Fire Fighter I Demonstration/Group Activity Remember to maintain an adequate instructor-to-student ratio. Purpose Following instructor-facilitated demonstrations, this activity allows students to observe and demonstrate competency in firefighting skills associated with portable fire extinguishers. Materials Needed 1. Carbon dioxide extinguisher 2. Stored-pressure water-type extinguisher 3. Multipurpose dry chemical extinguisher 4. Dry chemical extinguisher 5. Stored-pressure extinguisher containing AFFF or FFFP extinguishing agent 6. Wet chemical fire extinguisher 7. Halogenated extinguishing agent 8. Dry powder extinguishing agent 9. Pike pole Instructor Directions Skills 1. Demonstrate each skill, placing emphasis on describing to the students any critical points or procedures. 2. On the basis of the specific skill, assign each student to a partner or team. Provide each partner/team with equipment or materials as needed. 3. Direct students to practice each skill. Closely monitor the practice sessions and provide constructive comments and redirecting. 4. As individual students achieve success, track their skills and conduct skill proficiency exams using the Skill Drill Evaluation Sheets located on the Instructor s ToolKit CD-ROM. Students failing the exam should be given redirection and an opportunity to practice before being retested. A. Transporting a Fire Extinguisher (Skill Drill 7-1, Fire Fighter I) B. Operating a Carbon Dioxide Extinguisher (Skill Drill 7-2, Fire Fighter I) C. Attacking a Class A Fire with a Stored-Pressure Water-Type Fire Extinguisher (Skill Drill 7-3, Fire Fighter I) D. Attacking a Class A Fire with a Multipurpose Dry Chemical Fire Extinguisher (Skill Drill 7-4, Fire Fighter I) E. Attack a Class B Flammable Liquid Fire with a Dry Chemical Fire Extinguisher (Skill Drill 7-5, Fire Fighter I) F. Attacking a Class B Flammable Liquid Fire with a Stored-Pressure Foam Fire Extinguisher (AFFF or FFFP) (Skill Drill 7-6, Fire Fighter I) G. Using a Wet Chemical Fire Extinguisher (Skill Drill 7-7, Fire Fighter I) H. Use of Halogenated-Agent Extinguisher (Skill Drill 7-8, Fire Fighter I) I. Use of Dry Powder Fire Extinguishing Agents (Skill Drill 7-9, Fire Fighter I)

36 Chapter 7: Portable Fire Extinguishers 179 Lesson Plan Post-Lecture I. Wrap-Up Activities Time: 40 Minutes Level: Fire Fighter I Small Group Activity/Individual Activity/Discussion A. Fire Fighter in Action This activity is designed to assist the student in gaining a further understanding of portable fire extinguishers. The activity incorporates both critical thinking and the application of fire fighter knowledge. Purpose This activity allows students an opportunity to analyze a firefighting scenario and develop responses to critical thinking questions. Instructor Directions 1. Direct students to read the Fire Fighter in Action scenario located in the Wrap-Up section at the end of Chapter Direct students to read and individually answer the quiz questions at the end of the scenario. Allow approximately 10 minutes for this part of the activity. Facilitate a class review and dialogue of the answers, allowing students to correct responses as needed. Use the answers noted below to assist in building this review. Allow approximately 10 minutes for this part of the activity. 3. You may also assign these as individual activities and ask students to turn in their comments on a separate piece of paper. 4. Review the Near Miss Report. Advise students to prepare a written statement on how to eliminate this from happening in their department. Allow minutes for this activity. Answers to Multiple Choice Questions 1. D 2. D 3. C 4. D 5. D B. Technology Resources This activity requires students to have access to the Internet. This may be accomplished through personal access, employer access, or through a local educational institution. Some community colleges, universities, or adult education centers may have classrooms with Internet capability that will allow for this activity to be completed in class. Check out local access points and encourage students to complete this activity as part of their ongoing reinforcement of firefighting knowledge and skills. Purpose To provide students an opportunity to reinforce chapter material through use of online Internet activities. Instructor Directions 1. Use the Internet and go to Follow the directions on the Web site to access the exercises for Chapter Review the chapter activities and take note of desired or correct student responses. 3. As time allows, conduct an in-class review of the Internet activities and provide feedback to students as needed. 4. Be sure to check the Web site before assigning these activities, as specific chapter-related activities may change from time to time.

37 180 Fire Service Instructor: Principles and Practice, Second Edition II. Lesson Review Time: 15 Minutes Level: Fire Fighter I Discussion Note: Facilitate the review of this lesson s major topics using the review questions as direct questions or overhead transparencies. Answers are found throughout this lesson plan. Fire Fighter I A. In what stage of fire are fire extinguishers used? B. Describe each class of fire. C. How are fire extinguishers classified? D. Why is the pictograph labeling system required? E. What is the NFPA standard for portable fire extinguishers? F. Describe how occupancies are classified into hazards. G. How do fire extinguishers extinguish fires? H. What are the seven different types of extinguishing agents? I. Which type of extinguishing agents is referred to as a clean agent? J. What are the six basic components that make up a fire extinguisher? III. Assignments Time: 5 Minutes Level: Fire Fighter I Lecture A. Advise students to review materials for a quiz (determine date/time). B. Direct students to read the next chapter in Fundamentals of Fire Fighter Skills as listed in your syllabus (or reading assignment sheet) to prepare for the next class session.