Chemical agents toxicity

Chromium is rated as an immobile element, most of which is difficult to extract from soils even by aggressive chemical agents. Toxicity of Cr to plants is occasionally seen in unusually Cr-rich soils formed from the parent rock, serpentinite, or under high pH conditions favorable to Cr oxidation. 

A monitor is defined as a device used to locate chemical agent (toxic chemical) contamination and/or to confirm decontamination of chemical agents (toxic chemicals). The use of a monitor implies a requirement for an operator to perform judgements with respect to the response of the device prior to taking action. Speed of response and recovery from an exposure is critical in the design of a monitor. 

The modem history of the military use of toxic chemical agents (1,3—5) dates from the first full-scale (chlorine) gas attack on April 22, 1915, near Ypres, Belgium in World War I. There were a few reports of the limited use of toxic chemicals since that time. The Italians employed mustard, a bUster agent, during the Ethiopian war in 1935 and 1936 the Japanese used toxic chemicals in a number of small-scale engagements in the early years of their war with China and Iraq purportedly employed both mustard and nerve gases in the 1980s. 

Article containing both an explosive substance and a toxic chemical agent K... 

Chemical agents, including drugs Certain toxic compounds, therapeutic drugs, etc. 

As is apparent from the above information, there is no ideal disinfectant, antiseptic or preservative. All chemical agents have their limitations either in terms of their antimicrobial activity, resistance to organic matter, stability, incompatibility, irritancy, toxicity or corrosivity. To overcome the limitations of an individual agent, formulations consisting of combinations of agents are available. For example, ethanol has been combined with chlorhexidine and iodine to produce more active preparations. The combination of chlorhexidine and cetrimide is also considered to improve activity. QACs and phenols have been combined with glutaraldehyde so that the same effect can be achieved with lower, less irritant concentrations of glutaraldehyde. Some... 

Hazard characterization is a quantitative or semi-quantitative evaluation of the nature, severity, and duration of adverse health effects associated with biological, physical, or chemical agents that may be present in food. The characterization depends on the nature of the toxic effect or hazard. Eor some hazards such as genotoxic chemicals, there may be no threshold for the effect and therefore estimates are made of the possible magnitude of the risk at human exposure level (dose-response extrapolation). 

Rapid hydrolysis aids in lowering the duration of effectiveness of toxic chemical agents. For example, in the presence of water or water vapor, lewisite (L) rapidly hydrolyzes. Therefore, it has a shorter duration of effectiveness than distilled mustard (HD). 

McPhillips DM, Armer TA, Owen DR. 1983. Grafted synthetic sorbents for enhanced removal of toxic chemical agents from plasma. J Biomed Mater Res 17(6) 993-1002. 

Van Voris P, Cataldo DA, Ligotke MW, et al. 1987. Acute environmental toxicity and persistence of selected chemical agent simulants diisopropyl flourophosphate (DFP) and diisopropyl methylphosphonate (DIMP). NTIS No. AD-A181-309. 

Chemical reduction is used to transform a toxic substance with a higher valence to a nontoxic or less-toxic substance with lower valence. The most promising application is the reduction of hexava-lent chromium to trivalent chromium. This method is also applicable to other multivalent metals such as lead and mercury. Commonly used chemical agents for this purpose are sulfite salts, sulfur dioxide, and base metals (e.g., iron and aluminum).22 24... 

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