Smoke produced

Secondary smoke is produced mosdy by the condensation of water in humid or cold air. The presence of hydrogen chloride or hydrogen fluoride in the combustion products increases the extent and rate of condensation. Composition modifications to reduce primary smoke may reduce secondary smoke to some extent, but complete elimination is unlikely. The relatively small amount of smoke produced in gun firings by modem nitrocellulose propellants, although undesirable, is acceptable (102—109). 

At this writing anticholinergic agents are not widely used for the symptomatic treatment of asthma, although compounds such as atropine [51 -55-8] C17H23NO3, (18) have been used for centuries (111). Inhalation of the smoke produced by burning herbal mixtures, such as Datura Stramonium provided bronchodilation and rehef from some of the symptoms of asthma. The major active component in these preparations was atropine or other closely related alkaloids (qv). 

Steam Injection - While the multijet flare will achieve a significant reduction in the smoke produced, it does not provide true smokeless combustion over its full operating range. This is particularly true with the heavier (C4+) and unsamrated gases. Steam injection at a rate of about 0.5 kg steam per kg of gas will provide an additional reduction in smoke for most gases. Steam should be... 

These generators vaporize a liquid (oil/mineral oil or glycol and water), which then condenses into a fine aerosol on contact with cooler air. The amount of smoke produced should be controllable by the liquid feed rate and the temperature of the heating chamber, but in practice the output is not ea.sy to control. They will, however, produce a large amount of smoke over a long periled, dhe generators are relatively expensive (several hundred ECUs), are bulky, are not generally portable, and require an electrical connection. 

Kennedy describes a method using an ultrasonic nebulizer to generate a fog of water droplets w hich is used in the same way as smoke to visualize airflows. Several types of nebulizers are available but they require an electrical connection and are not hand-held. Food dye can be added to the water to produce colored fog. The nebulizers are expensive (about 1500 ECU) but have negligible operating costs. Although the amount of smoke produced is small, it is nontoxic and nonirritating. 

Interaction with sprinklers The likely size of fire will be smaller in buildings with sprinklers and the temperature of the smoke produced will be lower since the smoke is cooled by the sprinkler flow. 

Obscuring Power of White Smokes. The total obscuring power, TOP, of a white smoke agent used for screening purposes, is obtained by multiplying the product of volume, in cubic ft or smoke produced per lb of material, and the reciprocal of the smoke layer, in ft, necessary to obscure the filament of a 40-watt Mazda lamp. The TOP for some white smoke agents, at low altitudes where atm constituents are plentiful, is given in Table 1... 

AMOUNT OF SMOKE PRODUCED PER UNIT WEIGHT OF SMOKE AGENT AT 75% RELATIVE HUMIDITY... 

Petards (ou artifices 1 pour signaux (Fr). Used during WWI to attract the attention of neighboring troop units or fortifications. The devices consisted of boxes filled with about 400kgs of BlkPdr. They produced a report which could be heard for a distance of 3km, and the smoke produced gave the location of the signalling unit Ref Pepin Lehalleur (1935), 477... 

The smoke producing material and the pyrotechnic fuel block required to volatilize the smoke material are in separate compartments. The smoke-producing material is atomized and vaporized in the venturi nozzle by the hot gases formed by the burning of the fuel block... 

The smoke producing material is pulverized or atomized and then vaporized, or a preground solid is dispersed by the explosion of a bursting charge ... 

Field protection The principles applied to the nerve agents apply equally as well to the incapacitating agents. It is possible that such agents will be disseminated by smoke-producing munitions or aerosols, using the respiratory tract as a route of entry. The use of protective mask, therefore, is essential. The skin is usually a much less effective route. 

Because of the extreme importance of regularity and freedom from failure which must characterise safety fuse, detailed and exhaustive tests must be carried out on the product. Certain controls are obvious, namely, measurement of powder charge and of burning speed, both before and after immersion in water. Other tests usually carried out include resistance to cracking on flexing at low temperatures round a mandrel, coil tests in which the fuse is bunched into flat or complex coils and freedom from failure after immersion in water is determined. New types of fuse are usually tested to indicate the amount of smoke produced and also to determine the adequacy of the end spit. The end spit is the projection of particles of burning powder from a cut end and is of importance because it provides the mechanism which enables the fuse to ignite a detonator. 

The tabulated results for all samples tested can be found in Tables VIII and IX, with Figures 3 and 4 depicting the results graphically. Non-flaming conditions produce the most dramatic results. For the polycarbonate substrates all coatings except zinc increase the amount of smoke produced. Zinc shows... 

During the 1970 s and early 1980 s a large number of test methods were developed to measure the toxic potency of the smoke produced from burning materials. The ones most widely used are in refs. 29-32. These tests differ in several respects the conditions under which the material is burnt, the characteristics of the air flow (i.e. static or dynamic), the type of method used to evaluate smoke toxicity (i.e. analytical or bioassay), the animal model used for bioassay tests, and the end point determined. As a consequence of all these differences the tests result in a tremendous variation of ranking for the smoke of various materials. A case in point was made in a study of the toxic potency of 14 materials by two methods [33]. It showed (Table I) that the material ranked most toxic by one of the protocols used was ranked least toxic by the other protocol Although neither of these protocols is in common use in the late 1980 s, it illustrates some of the shortcomings associated with small scale toxic potency of smoke tests. 

Even children are not immune from poisoning by PCP. Six cases were observed at the UCLA Medical Center, all 5 years old or younger. Presumably, most were poisoned by accidental ingestion of the drug, which was available in the house one child, only 11 days old, was presumably poisoned by passive inhalation of the smoke produced by the adults around him. The most common clinical manifestations in these youngsters was bizarre behavior, lethargy, ataxia, and nystagmus (48). 

Hexachloroethane is a colorless solid that gradually evaporates when it is exposed to air. This compound is also called perchloroethane, carbon hexachloride, and HCE. It is sold under the trade names Avlothane, Distokal, Distopan, and Distopin. In the United States, about half of the hexachloroethane is used by the military for smoke-producing devices. It is also sold as degassing pellets that are used to remove the air bubbles in melted aluminum. Hexachloroethane may be present as an ingredient in some fungicides, insecticides, lubricants, plastics, and cellulose. At one time, hexachloroethane was prescribed for deworming animals. 

Hexachloroethane is released to the air during military operations and training exercises when smoke-producing devices containing it are used. In a smoke pot or grenade, most of it is used up by the smoke-producing reaction. Only small amounts (5% or less) remain after the smoke has formed. 

People who work with smoke-producing devices that contain hexachloroethane are exposed to it in the smoke. They can contact it through smoke particles on plants and in the soil. 

Hexachloroethane is a solid crystalline material that has entered the environment as a result of its use in militaiy pyrotechnics and as a component of smoke-producing devices used for screening or signaling purposes. It is an intermediate in the production of fluorocarbons, cleaning agents, and refrigerants and was... 

Hexachloroethane is not known to occur naturally (IARC 1979). Most of the hexachloroethane entering environmental media is from releases during manufacture and use of the compound in smoke-producing and pyrotechnic devices and as an intermediate in the production of several other products (Gordon et al. 

Special Chemical laboratory hoods will have an average inward face velocity of 100 linear feet per minute (lfpm) 20% with the velocity at any point not deviating from the average face velocity by more than 20%. Existing laboratory hoods will have an inward face velocity of 150 lfpm 20%. Laboratory hoods will be located such that cross drafts do not exceed 20% of the inward face velocity. A visual performance test using smoke producing devices will be performed in assessing the ability of the hood to contain Lewisite. 

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