Compressed gases flammable range

Compressed gas—flammable Any material which has a boiling point of 68°F (20 C) or less at 14.7 psia (101.3 kPa, abs) which is ignitable at 14.7 psia (101.3 kPa, abs) when in a mixture of 13 percent or less by volume with air and has a flammable range at 14.7 psia (101.3 kPa, abs) with air of at least 12 percent regardless of the lower limit. These limits shall be determined in accordance with ASTM E681-85, Standard Test Method for Concentration Limits of Flammability of Chemicals or an approved equivalent. 

The flammable range of a 2.1 compressed gas oceurs at which of the following... 

Millions of workers, homeowners, hobbyists, and educators handle and use gases in their daily activities. Most of those people have no technical expertise, yet they safely use potentially hazardous materials. Gases can be hazardous by virtue of pressure, flammability, oxygen deficiency, corrosivity, toxicity or other physical and chemical properties. The industrial gas industry and the Compressed Gas Association are proud that despite the range of hazards, the safety record of its products is among the best in industry. 

A four-carbon compound is named butane, with the molecular formula of 411,0. Structures, molecular formulas, and some physical characteristics of these alkane-compressed gas compounds are shown in Figure 4.8. Notice the differences in boiling points and flammable ranges. As the carbon content increases, the boiling point of the compounds increases. In addition to carbon content, polarity and branching of compounds will affect physical characteristics. This concept will be discussed in more detail in Chapter 5. For now, just be aware that there are relationships between the physical characteristics of flammable gases, which include ignition temperature, heat output, vapor content, and vapor pressure. 

A few hydrocarbon derivatives from the alkyl-halide family are 2.2 nonflammable compressed gases. This illustrates the wide range of hazards of the alkyl halides as a group. Some are flammable, some are toxic, and some are nonflammable and nontoxic. They can still act as asphyxiants and displace the oxygen in the air. It is important to remember that the primary hazard of the alkyl halides is toxicity. Some of them are also flammable therefore, all must be assumed to be toxic and flammable until the individual chemical is researched and the actual hazards are determined. It is interesting to note that while the DOT lists tetrafluoromethane as a nonflammable, nonpoisonous gas, the Condensed Chemical Dictionary lists the compound as toxic by inhalation. The NIOSH Pocket Guide to Chemical Hazards does not list the compound. The best source of information about this compound and others may be the MSDS (material safety data sheet). Examples of nonflammable Class 2.2 alkyl halides are tetrafluoromethane and trifluoromethane. 

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