Toxic industrial agents vapors

There are a myriad of applications for chemical sensors, and one important area is the detection of toxic gases and vapors. Toxic industrial chemicals and materials (referred to as TICs and TIMs) represent one class of materials for which chemical sensors are designed and applied. Chemical warfare agents (CWAs) are another set of materials for which chemical sensors are used, and they represent one of the most challenging groups of analytes due to their extreme toxicity, which translates to a very low required detection limit. Detection of explosives additionally requires high sensitivities due to the low vapor pressures of the explosive materials (order of magnitude 6 x 10-6 Torr for TNT and 5 x 10 9 Torr for RDX). 

Figure 9.41 displays a DMS vapor detector, battery powered, weighing only 2 lb. Use of DMS mode improves sensitivity and allows it to be tuned to detect specific compounds, improving selectivity and allowing it to detect trace levels with fewer false alarms. It can monitor most chemical warfare agents, particularly the five major nerve agents, and toxic industrial vapors such as HCN, CI2, H2S,... 

Use and exposure Diborane is a colorless gas at room temperature with a repulsive, sweet odor. It mixes well with air and easily forms explosive mixtures. Diborane will ignite spontaneously in moist air at room temperature and can cause explosions. Diborane is used in rocket propellants and as a reducing agent, a rubber vulcanizer, a catalyst for hydrocarbon polymerization, a flame-speed accelerator, and a doping agent. Diborane is a very toxic and flammable gas used by chemists to make other compounds. It is also used in electronics to impart electrical properties in pure crystals. Industrial workers are exposed to diborane by breathing in its vapors in work areas. - ... 

Toxicity follows exposure to chemical agents dispersed as solids, liquids, aerosols, or vapor (Table 23.1). CW agents have characteristics that make them uniquely suited to warfare. In addition to their extreme toxicity, their chemical structures are simple, and the manufacturing processes for most are relatively uncomplicated and inexpensive. Cyanide and phosgene are manufactured in large quantities for use in industry and are shipped in bulk by truck or train. 

The toxic character of aniline vapors and the vicissitudes of industrial operations make it desirable to provide a fireproof housing with ample headroom and also adequate ventilation. It is, furthermore, customary to separate the high-pressure autoclave work from the subsequent separation and distillation operations. The autoclaves, which may be either vertical or horizontal, are ordinarily made of rolled steel. They are generally jacketed for use with high-pressure steam or a fluid heat-transfer agent. It... 

Another major use of tetrachloroethylene is as a vapor and liquid degreasing agent. Since tetrachloroethylene dissolves many organic compounds, select inorganic compounds, and high-melting pitehes and waxes, it can be used to clean and dry contaminated metal parts and other fabricated materials. It is also used to remove soot from industrial boilers (Verschueren 1983). Tetrachloroethylene has been used as an anthelmintic in the treatment of hookworm and some nematode infestations, but it has been replaced by drugs that are less toxic and easier to administer (Budavari 1989 HSDB 1996). 

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