Explosive limits upper limit

Explosive limits upper limits, 95% lower, 2% by volume in air (American Conference of Governmental Industrial Hygienists, 1991)... 

UEL/UEL Upper Explosive Limit/Upper Elammable Limit... 

Tlie remainder of tliis cliapter provides information on relative physical properties of materials (flash points, upper and lower explosive limits, tlireshold limit values, etc.) and metliods to calculate tlie conditions tliat approach or are conducive to liazardous levels. Fire liazards in industrial plants are covered in Sections 7.2 and 7.3, and Sections 7.4 and 7.5 focus on accidental explosions. Sections 7.6 and 7.7 address toxic emissions and liazardous spills respectively. tliese latter types of accident frequently result in fires and explosions tliey can cause deatlis, serious injuries and financial losses. 

Explosive limits Upper, 46% lower, 4.3% (by volume in Budavari et al. 1996... 

Explosive limits. Upper, 15% lower, 9% by volume (United States National Library of Medicine, 1998a)... 

Explosive limits Lower limit Upper limit 0.9% 6% McDermott 1975... 

Explosive Limits—Upper and Lower Volume Percent Substance in Air ... 

Lower explosive limit Upper explosive limit Autoignition temperature Electrical conductivity Health hazards... 

Flash points and autoignition temperatures are given in Table 11. The vapor can travel along the ground to an ignition source. In the event of fire, foam, carbon dioxide, and dry chemical are preferred extinguishers. The lower and upper explosion limits are 1% and 7%. 

Flammability Acrolein is very flammable its flash point is <0° C, but a toxic vapor cloud will develop before a flammable one. The flammable limits in air are 2.8% and 31.0% lower and upper explosive limits, respectively by volume. Acrolein is only partly soluble in water and will cause a floating fire, so alcohol type foam should be used in firefighting. The vapors are heavier than air and can travel along the ground and flash back from an ignition source. 

The relatively low flash points of some acrylates create a fire hazard. Also, the ease of polymerization must be home in mind in ah. operations. The lower and upper explosive limits for methyl acrylate are 2.8 and 25 vol %, respectively. Corresponding limits for ethyl acrylate are 1.8 vol % and saturation, respectively. All possible sources of ignition of monomers must be eliininated. 

The explosive limits of hydrazine in air are 4.7—100 vol %, the upper limit (100 vol %) indicating that hydrazine vapor is self-explosive. Decomposition can be touched off by catalytic surfaces. The presence of inert gases significantly raises the lower explosive limit (10) (Table 2). 

Health and Safety Factors, Toxicology. Because low molecular weight phosphines generally are spontaneously flammable, they must be stored and handled in an inert atmosphere. The upper explosion limit is 1.6% and the upper limit is near 100% (93). The higher and less volatile homologues are more slowly oxidized by air and present less of a problem. 

Because biphenyl is often transported in the molten state, a moderate fire ha2ard does exist under these circumstances. Biphenyl, with a flash point of 113°C, has a lower flammability limit of about 0.6% (by volume) at the flash point to an upper limit of 5.8% at 166°C (42). Dust explosions are a ha2ard when vapors from a hot Hquid surface condense in air in a confined space. 

Figure 2.1 The lower and upper limits of an explosive chain reaction as a function of temperature and pressure.

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