NFPA flammable categories

Methane has a GHS flammability rating of 1 (NFPA rating of 4), putting it in the extremely flammable category. A methane leak in a lab is extremely dangerous. The lower explosive level (LEL) is 4.5% and the upper explosive level (UEL) is 16.5%. A sulfur compound, often ethyl mercaptan or a mixture of mercaptans, is added to natural gas to give it an unpleasant odor and allow for easy detection. The complete combustion of methane produces carbon dioxide and water ... 

These markings provide a general idea of the hazards of a material and the severity of these hazards as they relate to handling, fire protection, exposure, and control. This standard is not applicable to transportation or to use by the general public. It is also not applicable to chronic exposure. For a full description of this standard, refer to NFPA 704. The system identifies the hazards of a material in four principal categories health, flammability, reactivity, and unusual hazards such as reactivity with water. 

Poison A gas explosives-A/B, organic peroxide, flammable solid, materials dangerous when wet, chlorine, flourine, anhydrous ammonia, radioactive materials, NFPA 3 4 for any categories including SF>ecial hazards. PCB s fire, DOT inhalation hazzird, EPA extremely hazardous substances, and cryogenics. 

Class I, II and III are also used by NFPA to define the range of certain materials in categories based mainly on flash points. Class II and III materials generally do not provide sufficient vapors to require specification of an electrically classified area, so areas are only defined by Class I flammable materials. 

This system recognizes the hazards of a material in terms of three principal categories, namely "health," "flammability," and "reactivity" and ranks the severity numerically ranging from "four (4)," indicating a severe hazard, to "zero (0)," indicating no special hazard. The information is displayed in the NFPA 704 diamond, which is shown in Figure 6.27. For more information, you should consult the NFPA Fire Protection Guide on Hazardous Materials. 

SLIGHT Irritation or minor reversible injury possible. Materials (hat must be preheated before ignition will occur. Flammable liquids in this category will have flash points (the lowest temperature at which ignition will occur) at or above 200 F (93 C) (NFPA Class IflB). Materials that are normally stable but can become unstable at high temperatures and pressures. These materials may react with water but they will not release energy violently. 

The NFPA uses a classification system for flammable and combustible liquids in fixed storage facilities (see Figure 5.1). This system is part of the consensus standard NFPA 30, the Flammable and Combustible Liquids Code. The NFPA system further divides the flammable and combustible liquid categories into subdivisions based upon the flash points and boiling points of the liquids. NFPA s classification system does not apply to transportation of hazardous materials, since DOT regulations supersede NFPA 30. Examples of liquids in the various classification categories are listed in Figure 5.2. 

E. National Fire Protection Association (NFPA) codes are part of the system created by the NFPA for identifying and ranking the potential fire hazards of materials. The system has three principal categories of hazard health (H), flammability (F), and reactivity (R). Within each category, hazards are ranked from four (4), indicating a severe hazard, to zero (0), indicating no... 

As seen in Table 1.3 and discussed in Section 1.4, data on the flammability of organic compounds are tabulated and, for those compounds not included in the table, methods are available to estimate the data. In addition, tables of flammability data are also available for aerosols and polymers in Perry s Chemical Engineers Handbook (Perry and Green, 1997). The NFPA ratings provide a less quantitative source for many chemicals under Flammability Hazard, which is the second of the three categories (also rated from 0 to 4). 

In the USA flammable liquids are divided into six categories, again based on their flash point and boiling point as shown in Table 4.5. These are used in the NFPA hazard rating system [23] to provide a numerical rating of 0-4 for the three regular hazards health flammability and reactivity. Thousands of materials including solvents are covered. 

A system of labeling established by the National Fire Protection Association (NFPA) to provided a readily identifiable means to ascertain material hazards. The system identifies fire hazards in three main areas health, flammability, and reaction or instability. The relative ranking in severity of each hazard category is indicated... 

The hazards in this demonstration are the mineral salts, methanol, and the flame. Some of the mineral salts are toxic if ingested or cause skin irritation. The most important hazard in this demonstration was methanol, a highly flammable liquid - it has a boiling point of 64.7 °C, a flash point of 11.1 °C, and a vapor pressure of 96 mm Hg at 20 °C. It is a GHS Hazard Category 2 Highly Flammable Liquid (NFPA 3). 

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