"NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response" is a standard maintained by the U.S.-based National Fire Protection Association. First "tentatively adopted as a guide" in 1960,[1] and revised several times since then, it defines the "Safety Square" or "Fire Diamond" which is used to quickly and easily identify the risks posed by hazardous materials. This helps determine what, if any, special equipment should be used, procedures followed, or precautions taken during the initial stages of an emergency response. It is an internationally accepted safety standard, and is crucial while transporting chemicals.
Standard System for the Identification of the Hazards of Materials for Emergency Response
The four divisions are typically color-coded with red on top indicating flammability, blue on the left indicating level of health hazard, yellow on the right for chemical reactivity, and white containing codes for special hazards. Each of health, flammability and reactivity is rated on a scale from 0 (no hazard) to 4 (severe hazard). The latest version of NFPA 704 sections 5, 6, 7 and 8 for the specifications of each classification are listed below. The numeric values in the first column are designated in the standard by "Degree of Hazard" using Arabic numerals (0, 1, 2, 3, 4), not to be confused with other classification systems, such as that in the NFPA 30 Flammable and Combustible Liquids Code, where flammable and combustible liquid categories are designated by "Class", using Roman numerals (I, II, III).[2]
Flammability (red)
0
Materials that will not burn under typical fire conditions (e.g. carbon tetrachloride, silicon dioxide, perfluorohexane), including intrinsically noncombustible materials such as concrete, stone, and sand. Materials that will not burn in air unless exposed to a temperature of 820 °C (1,500 °F) for more than 5 minutes.
1
Materials that require considerable preheating, under all ambient temperature conditions, before ignition and combustion can occur (e.g. mineral oil, ammonia, ethylene glycol). Includes some finely divided suspended solids that do not require heating before ignition can occur. Flash point at or above 93.3 °C (200 °F).
2
Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur (e.g. diesel fuel, paper, sulfur and multiple finely divided suspended solids that do not require heating before ignition can occur). Flash point between 37.8 and 93.3 °C (100 and 200 °F).
3
Liquids and solids (including finely divided suspended solids) that can be ignited under almost all ambient temperature conditions (e.g. acetone, ethanol). Liquids having a flash point below 22.8 °C (73 °F) and having a boiling point at or above 37.8 °C (100 °F) or having a flash point between 22.8 and 37.8 °C (73 and 100 °F).
4
Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily (e.g. gasoline, acetylene, propane, hydrogen gas, diborane). Includes pyrophoric substances. Flash point below room temperature at 22.8 °C (73 °F).
Health (blue)
0
Poses no health hazard, requires no precautions, and would offer no hazard beyond that of ordinary combustible materials (e.g. wood, sugar, salt, propylene glycol)
Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water (e.g. white phosphorus, potassium, sodium)
3
Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked (e.g. ammonium nitrate, caesium, hydrogen peroxide)
The white "special notice" area can contain several symbols. The following symbols are defined by the NFPA 704 standard.
OX
Oxidizer, allows chemicals to burn without an air supply (e.g. potassium perchlorate, ammonium nitrate, hydrogen peroxide).
W
Reacts with water in an unusual or dangerous manner (e.g. caesium, sodium, diborane, sulfuric acid).
SA
Simple asphyxiant gas (specifically helium, nitrogen, neon, argon, krypton, xenon). The SA symbol shall also be used for liquified carbon dioxide vapor withdrawal systems and where large quantities of dry ice are used in confined areas.[2]
Non-standard symbols (white)
These hazard codes are not part of the NFPA 704 standard, but are occasionally used in an unofficial manner. The use of non-standard codes may be permitted, required or disallowed by the authority having jurisdiction (e.g. fire department).
The development of NFPA 704 is credited to the Charlotte Fire Department after a fire at the Charlotte Chemical Company in 1959 led to severe injuries to many of the firefighters.[3][4] Upon arrival, the fire crew found a fire burning inside a vat that firefighters assumed to be burning kerosene. The crew tried to suppress the fire, which resulted in the vat exploding due to metallic sodium being stored in the kerosene. Thirteen firefighters were injured, including several of whom had critical injuries and one who lost both ears and most of his face from the incident.
At the time, such vats were not labelled with the materials they contained, so firefighters did not have the necessary information to recognize that hazardous materials were present, which required a specific response. In this case, sodium was able to react with water to release hydrogen gas and large amounts of heat, which has the potential to explode.
The Charlotte Fire Department developed training to respond to fires involving hazardous materials, ensured that protective clothing was available to those responding, and expanded the fire prevention inspection program. Fire Marshal J. F. Morris developed the diamond shaped placard as a marking system to indicate when a building contained hazardous materials, with their levels of flammability, reactivity and health effects. [5]
^Dornette, W. H. L.; Woodworth, Miles E. (1969). (PDF). National Fire Protection Association. Archived from the original (PDF) on 2016-03-03. Retrieved 2016-03-04.
^ ab"NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response". 2017.
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NFPA 704 Standard System for the Identification of the Hazards of Materials for Emergency Response is a standard maintained by the U S based National Fire Protection Association First tentatively adopted as a guide in 1960 1 and revised several times since then it defines the Safety Square or Fire Diamond which is used to quickly and easily identify the risks posed by hazardous materials This helps determine what if any special equipment should be used procedures followed or precautions taken during the initial stages of an emergency response It is an internationally accepted safety standard and is crucial while transporting chemicals NFPA 704fire diamond444WNFPA 704 safety squares on containers of ethyl alcohol and acetone Contents 1 Codes 2 History 3 See also 4 References 5 External linksCodes edit nbsp Standard System for the Identification of the Hazards of Materials for Emergency ResponseThe four divisions are typically color coded with red on top indicating flammability blue on the left indicating level of health hazard yellow on the right for chemical reactivity and white containing codes for special hazards Each of health flammability and reactivity is rated on a scale from 0 no hazard to 4 severe hazard The latest version of NFPA 704 sections 5 6 7 and 8 for the specifications of each classification are listed below The numeric values in the first column are designated in the standard by Degree of Hazard using Arabic numerals 0 1 2 3 4 not to be confused with other classification systems such as that in the NFPA 30 Flammable and Combustible Liquids Code where flammable and combustible liquid categories are designated by Class using Roman numerals I II III 2 Flammability red 0 Materials that will not burn under typical fire conditions e g carbon tetrachloride silicon dioxide perfluorohexane including intrinsically noncombustible materials such as concrete stone and sand Materials that will not burn in air unless exposed to a temperature of 820 C 1 500 F for more than 5 minutes 1 Materials that require considerable preheating under all ambient temperature conditions before ignition and combustion can occur e g mineral oil ammonia ethylene glycol Includes some finely divided suspended solids that do not require heating before ignition can occur Flash point at or above 93 3 C 200 F 2 Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur e g diesel fuel paper sulfur and multiple finely divided suspended solids that do not require heating before ignition can occur Flash point between 37 8 and 93 3 C 100 and 200 F 3 Liquids and solids including finely divided suspended solids that can be ignited under almost all ambient temperature conditions e g acetone ethanol Liquids having a flash point below 22 8 C 73 F and having a boiling point at or above 37 8 C 100 F or having a flash point between 22 8 and 37 8 C 73 and 100 F 4 Will rapidly or completely vaporize at normal atmospheric pressure and temperature or is readily dispersed in air and will burn readily e g gasoline acetylene propane hydrogen gas diborane Includes pyrophoric substances Flash point below room temperature at 22 8 C 73 F Health blue 0 Poses no health hazard requires no precautions and would offer no hazard beyond that of ordinary combustible materials e g wood sugar salt propylene glycol 1 Exposure would cause irritation with only minor residual injury e g acetone sodium bromate potassium chloride 2 Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury e g diethyl ether ammonium phosphate carbon dioxide chloroform DEET 3 Short exposure could cause serious temporary or moderate residual injury e g liquid hydrogen sulfuric acid calcium hypochlorite carbon monoxide hexafluorosilicic acid zinc chloride sodium hydroxide 4 Very short exposure could cause death or major residual injury e g hydrogen cyanide phosgene diborane methyl isocyanate hydrofluoric acid Instability reactivity yellow 0 Normally stable even under fire exposure conditions and is not reactive with water e g helium N2 carbon dioxide 1 Normally stable but can become unstable at elevated temperatures and pressures e g propene ammonium acetate carbonic acid 2 Undergoes violent chemical change at elevated temperatures and pressures reacts violently with water or may form explosive mixtures with water e g white phosphorus potassium sodium 3 Capable of detonation or explosive decomposition but requires a strong initiating source must be heated under confinement before initiation reacts explosively with water or will detonate if severely shocked e g ammonium nitrate caesium hydrogen peroxide 4 Readily capable of detonation or explosive decomposition at normal temperatures and pressures e g nitroglycerin chlorine dioxide nitrogen triiodide manganese heptoxide TNT Picric acid Special notice white The white special notice area can contain several symbols The following symbols are defined by the NFPA 704 standard OX Oxidizer allows chemicals to burn without an air supply e g potassium perchlorate ammonium nitrate hydrogen peroxide W Reacts with water in an unusual or dangerous manner e g caesium sodium diborane sulfuric acid SA Simple asphyxiant gas specifically helium nitrogen neon argon krypton xenon The SA symbol shall also be used for liquified carbon dioxide vapor withdrawal systems and where large quantities of dry ice are used in confined areas 2 Non standard symbols white These hazard codes are not part of the NFPA 704 standard but are occasionally used in an unofficial manner The use of non standard codes may be permitted required or disallowed by the authority having jurisdiction e g fire department COR Corrosive strong acid or base e g sulfuric acid potassium hydroxide ACID Acid or alkaline to be more specificALKBIO Biological hazard e g flu virus rabies virus nbsp POI Poisonous e g strychnine alpha amanitin RA Radioactive e g plutonium cobalt 60 carbon 14 RAD nbsp CRY Cryogenic e g liquid nitrogen CRYOHistory editThe development of NFPA 704 is credited to the Charlotte Fire Department after a fire at the Charlotte Chemical Company in 1959 led to severe injuries to many of the firefighters 3 4 Upon arrival the fire crew found a fire burning inside a vat that firefighters assumed to be burning kerosene The crew tried to suppress the fire which resulted in the vat exploding due to metallic sodium being stored in the kerosene Thirteen firefighters were injured including several of whom had critical injuries and one who lost both ears and most of his face from the incident At the time such vats were not labelled with the materials they contained so firefighters did not have the necessary information to recognize that hazardous materials were present which required a specific response In this case sodium was able to react with water to release hydrogen gas and large amounts of heat which has the potential to explode The Charlotte Fire Department developed training to respond to fires involving hazardous materials ensured that protective clothing was available to those responding and expanded the fire prevention inspection program Fire Marshal J F Morris developed the diamond shaped placard as a marking system to indicate when a building contained hazardous materials with their levels of flammability reactivity and health effects 5 See also editGlobally Harmonized System of Classification and Labeling of Chemicals Hazard symbol HMIS Color Bar Hazchem HazmatReferences edit Dornette W H L Woodworth Miles E 1969 Proposed Amendments on Revisions to the Recommended System for the Identification of The Fire Hazards of Materials NFPA No 704M 1969 PDF National Fire Protection Association Archived from the original PDF on 2016 03 03 Retrieved 2016 03 04 a b NFPA 704 Standard System for the Identification of the Hazards of Materials for Emergency Response 2017 Fact Friday 153 Charlotte s Haz Mat History 704 Shop Retrieved 2022 02 22 July marks 62 years since Charlotte Fire invented Haz Mat safety measure Queen City News 2021 06 28 Retrieved 2022 02 22 History of the Charlotte Fire Department PDF Archived from the original PDF on 2023 04 07 Retrieved 2022 02 22 External links edit nbsp Wikimedia Commons has media related to NFPA 704 images Frequently Asked Questions on NFPA 704 PDF Archived from the original PDF on 2017 07 16 Retrieved 2016 03 04 Pamphlet produced by the City of Milwaukee summarizing NFPA 704 code requirements PDF City of Milwaukee Hazard Communication Occupational Safety and Health Administration Safety in the Chemistry Laboratory NFPA 704 Hazard Identification System University of Oregon Archived from the original on 2015 03 10 Portal nbsp United States Retrieved from https en wikipedia org w index php title NFPA 704 amp oldid 1186292897, wikipedia, wiki, book, books, library,
