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SOURCE: National Fire Protection Association Fire Protection Guide on Hazardous Materials Eleventh Edition, NFPA 325 Fire Hazard Properties of Flammable Liquids, Gases, Volatile Solids 1994,
LIST DESCRIPTION: The National Fire Protection Association was organized in 1896 to promote the science and improve the methods of fire protection and fire prevention. It is a nonprofit, educational, voluntary-membership organization recognized internationally as a clearinghouse for information on fire prevention, fire fighting procedures and means of fire protection. It is also recognized internationally as an authoritative source for fire-loss experience. The 1994 edition (eleventh edition) is an amended version of the 1991 edition.
The information in NFPA 325 is not a code, standard or recommended practice, as these terms are defined by NFPA. It is only a compilation of basic fire protection properties of various materials, prefaced by an explanation of the properties covered. the data contained have been collected from numerous authoritative sources, including the U.S.Bureau of Mines, Factory Mutual Research Corporation, and Underwriters Laboratories, as well as from the manufacturers of the materials. The originating source of the data is on file at NFPA headquarters and may be obtained upon request.
The increased use of chemicals, many of which introduce hazards other than flammability, led to the need for a simple hazard identification system that could be immediately recognized by emergency response personnel. This led to the development of NFPA 704 Hazard Identification System, otherwise known as the NFPA diamond. This system is completely described in NFPA 704 -Recommended System for the Identification of the Fire Hazard of Materials. This system provides simple, readily recognized and easily understood markings that give, at a glance, a general idea of the inherent hazards of the material and the order of severity of these hazards as they relate to fire protection, exposure, and control. The system's objectives are to provide an appropriate alert signal and on-the-spot information to safeguard the lives of both public and private emergency response personnel. The system also assists in planning for effective fire fighting operations and may be used by plant design engineers and plant protection and safety personnel.
The system identifies the hazards of a material in terms of three categories - Health, Flammability, and Reactivity. It indicates the order of severity of these hazards by means of a numerical rating of 0, indicating no special hazard, to 4, indicating extreme hazard. The three hazard categories were selected after studying about 35 inherent and environmental hazards of materials that could affect fire fighting operations. The five degrees of hazard were decided upon as necessary to give the required information.
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NFPA - Hazard Identification Ratings
SOURCE: National Fire Protection Association Fire Protection Guide on Hazardous Materials Eleventh Edition, NFPA 325 Fire Hazard Properties of Flammable Liquids, Gases, Volatile Solids 1994,
LIST DESCRIPTION: The National Fire Protection Association was organized in 1896 to promote the science and improve the methods of fire protection and fire prevention. It is a nonprofit, educational, voluntary-membership organization recognized internationally as a clearinghouse for information on fire prevention, fire fighting procedures and means of fire protection. It is also recognized internationally as an authoritative source for fire-loss experience. The 1994 edition (eleventh edition) is an amended version of the 1991 edition.
The information in NFPA 325 is not a code, standard or recommended practice, as these terms are defined by NFPA. It is only a compilation of basic fire protection properties of various materials, prefaced by an explanation of the properties covered. the data contained have been collected from numerous authoritative sources, including the U.S.Bureau of Mines, Factory Mutual Research Corporation, and Underwriters Laboratories, as well as from the manufacturers of the materials. The originating source of the data is on file at NFPA headquarters and may be obtained upon request.
The increased use of chemicals, many of which introduce hazards other than flammability, led to the need for a simple hazard identification system that could be immediately recognized by emergency response personnel. This led to the development of NFPA 704 Hazard Identification System, otherwise known as the NFPA diamond. This system is completely described in NFPA 704 -Recommended System for the Identification of the Fire Hazard of Materials. This system provides simple, readily recognized and easily understood markings that give, at a glance, a general idea of the inherent hazards of the material and the order of severity of these hazards as they relate to fire protection, exposure, and control. The system's objectives are to provide an appropriate alert signal and on-the-spot information to safeguard the lives of both public and private emergency response personnel. The system also assists in planning for effective fire fighting operations and may be used by plant design engineers and plant protection and safety personnel.
The system identifies the hazards of a material in terms of three categories - Health, Flammability, and Reactivity. It indicates the order of severity of these hazards by means of a numerical rating of 0, indicating no special hazard, to 4, indicating extreme hazard. The three hazard categories were selected after studying about 35 inherent and environmental hazards of materials that could affect fire fighting operations. The five degrees of hazard were decided upon as necessary to give the required information.
The following commentary on degrees of hazard are an interpretation of the information contained within NFPA 704 and are related specifically to the fire fighting aspects. Refer to NFPA 704 for a detailed discussion of the identification system.
NOTE: The hazard identification rating definitions below and the actual ratings in the text are based on definitions from the 1985 edition of NFPA 704. Materials have not been rated using the new definitions appearing in the 1990 edition of NFPA 704.
HEALTH HAZARD RATING: In general, health hazard in fire fighting is that of a single exposure which may vary from a few seconds up to an hour. Only hazards arising out of an inherent property of the material are considered. The following explanation is based upon protective equipment normally used by fire fighters.
4: Materials too dangerous to health to expose fire fighters. A few whiffs of the vapor could cause death or the vapor or liquid could be fatal on penetrating the fire fighter's normal full protective clothing. The normal full protective clothing and breathing apparatus available to the average fire department will not provide adequate protection against inhalation or skin contact with these materials. 3: Materials extremely hazardous to health but areas may be entered with extreme care. Full protective clothing, including self-contained breathing apparatus, coat, pants, gloves, boots, and bands around legs, arms and waist should be provided. No skin surface should be exposed. 2: Materials hazardous to health, but areas may be entered freely with full-faced mask self-contained breathing apparatus which provides eye protection. 1: Materials only slightly hazardous to health. It may be desirable to wear self-contained breathing apparatus. 0: Materials which on exposure under fire conditions would offer no hazard beyond that of ordinary combustible material.
FLAMMABILITY HAZARD RATING: Susceptibility to burning is the basis for assigning degrees within this category. The method of attacking the fire is influenced by this susceptibility factor.
4: Very flammable gases or very volatile flammable liquids. Shut off flow and keep cooling water streams on exposed tanks or containers. 3: Materials which can be ignited under almost all normal temperature conditions. Water may be ineffective because of the low flash point. 2: Materials which must be moderately heated before ignition will occur. Water spray may be used to extinguish the fire because the material can be cooled below its flash point. 1: Materials that must be preheated before ignition can occur. Water may cause frothing if it gets below the surface of the liquid and turns to steam. However, water fog gently applied to the surface will cause a frothing which will extinguish the fire. 0: Materials that will not burn.
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The following commentary on degrees of hazard are an interpretation of the information contained within NFPA 704 and are related specifically to the fire fighting aspects. Refer to NFPA 704 for a detailed discussion of the identification system.
NOTE: The hazard identification rating definitions below and the actual ratings in the text are based on definitions from the 1985 edition of NFPA 704. Materials have not been rated using the new definitions appearing in the 1990 edition of NFPA 704.
HEALTH HAZARD RATING: In general, health hazard in fire fighting is that of a single exposure which may vary from a few seconds up to an hour. Only hazards arising out of an inherent property of the material are considered. The following explanation is based upon protective equipment normally used by fire fighters.
4: Materials too dangerous to health to expose fire fighters. A few whiffs of the vapor could cause death or the vapor or liquid could be fatal on penetrating the fire fighter's normal full protective clothing. The normal full protective clothing and breathing apparatus available to the average fire department will not provide adequate protection against inhalation or skin contact with these materials. 3: Materials extremely hazardous to health but areas may be entered with extreme care. Full protective clothing, including self-contained breathing apparatus, coat, pants, gloves, boots, and bands around legs, arms and waist should be provided. No skin surface should be exposed. 2: Materials hazardous to health, but areas may be entered freely with full-faced mask self-contained breathing apparatus which provides eye protection. 1: Materials only slightly hazardous to health. It may be desirable to wear self-contained breathing apparatus. 0: Materials which on exposure under fire conditions would offer no hazard beyond that of ordinary combustible material.
FLAMMABILITY HAZARD RATING: Susceptibility to burning is the basis for assigning degrees within this category. The method of attacking the fire is influenced by this susceptibility factor.
4: Very flammable gases or very volatile flammable liquids. Shut off flow and keep cooling water streams on exposed tanks or containers. 3: Materials which can be ignited under almost all normal temperature conditions. Water may be ineffective because of the low flash point. 2: Materials which must be moderately heated before ignition will occur. Water spray may be used to extinguish the fire because the material can be cooled below its flash point. 1: Materials that must be preheated before ignition can occur. Water may cause frothing if it gets below the surface of the liquid and turns to steam. However, water fog gently applied to the surface will cause a frothing which will extinguish the fire. 0: Materials that will not burn.
REACTIVITY HAZARD RATING: The assignment of degrees in the reactivity category is based upon the susceptibility of materials to release energy either by themselves or in combination with water. Fire exposure was one of the factors considered along with conditions of shock and pressure.
4: Materials which (in themselves) are readily capable of detonation or of explosive decomposition or explosive reaction at normal temperatures and pressures. Includes materials which are sensitive to mechanical or localized thermal shock. If a chemical with this hazard rating is in an advanced or massive fire, the area should be evacuated. 3: Materials which (in themselves) are capable of detonation or of explosive decomposition or of explosive reaction but which require a strong initiating source or which must be heated under confinement before initiation. Includes materials which are sensitive to thermal or mechanical shock at elevated temperatures and pressure or which react explosively with water without requiring heat or confinement. Fire fighting should be done from an explosion-resistant location. 2: Materials which (in themselves) are normally unstable and readily undergo violent chemical change but do not detonate. Includes materials which can undergo chemical change with rapid release of energy at normal temperatures and pressures or which can undergo violent chemical change at elevated temperatures and pressures. Also includes those materials which may react violently with water or which may form potentially explosive mixtures with water. In advanced or massive fires, fire fighting should be done from a safe distance or from a protected location. 1: Materials which (in themselves) are normally stable but which may become unstable at elevated temperatures and pressures or which may react with water with some release of energy but not violently. Caution must be used in approaching the fire and applying water. 0: Materials which (in themselves) are normally stable even under fire exposure conditions and which are not reactive with water. Normal fire fighting procedures may be used.
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REACTIVITY HAZARD RATING: The assignment of degrees in the reactivity category is based upon the susceptibility of materials to release energy either by themselves or in combination with water. Fire exposure was one of the factors considered along with conditions of shock and pressure.
4: Materials which (in themselves) are readily capable of detonation or of explosive decomposition or explosive reaction at normal temperatures and pressures. Includes materials which are sensitive to mechanical or localized thermal shock. If a chemical with this hazard rating is in an advanced or massive fire, the area should be evacuated. 3: Materials which (in themselves) are capable of detonation or of explosive decomposition or of explosive reaction but which require a strong initiating source or which must be heated under confinement before initiation. Includes materials which are sensitive to thermal or mechanical shock at elevated temperatures and pressure or which react explosively with water without requiring heat or confinement. Fire fighting should be done from an explosion-resistant location. 2: Materials which (in themselves) are normally unstable and readily undergo violent chemical change but do not detonate. Includes materials which can undergo chemical change with rapid release of energy at normal temperatures and pressures or which can undergo violent chemical change at elevated temperatures and pressures. Also includes those materials which may react violently with water or which may form potentially explosive mixtures with water. In advanced or massive fires, fire fighting should be done from a safe distance or from a protected location. 1: Materials which (in themselves) are normally stable but which may become unstable at elevated temperatures and pressures or which may react with water with some release of energy but not violently. Caution must be used in approaching the fire and applying water. 0: Materials which (in themselves) are normally stable even under fire exposure conditions and which are not reactive with water. Normal fire fighting procedures may be used.