Hazard factors that produce

Rapid-acting dermally hazardous cytotoxin that inhibits protein synthesis and affects clotting factors in the blood. It is capable of producing incapacitating or lethal effects. T2 is obtained from various molds and fungi (Fusarium sp.). It is a colorless crystalline solid of white powder that melts at 304°F. Impure samples may be a colorless to slightly yellow oil. It is slightly soluble in water, but soluble in ethyl acetate, acetone, ethanol, chloroform, methylene chloride, diethyl ether, and dimethyl sulfoxide (DMSO). It is heat stable and can be stored at room temperature for years. 

Exposure to combinations of chemicals does not always necessarily produce clearly distinguishable interactions. Each situation must be considered in detail with due regard to all the factors that are required to be analyzed in the process of hazard evaluation (59,60). 

Hazard is the likelihood that the known toxicity of a material will be exhibited under specific conditions of use. It follows that the toxicity of a material, ie, its potential to produce injury, is but one of many considerations to be taken into account in assessment procedures with respect to defining hazard. The following are equally important factors that need to be considered physicochemical properties of the material use pattern of the material and characteristics of the environment where the material is handled source of exposure, normal and accidental control measures used to regulate exposure the duration, magnitude, and frequency of exposure route of exposure and physical nature of exposure conditions, eg, gas, aerosol, or liquid population exposed and variability in exposure conditions and experience with exposed human populations. 

Many finely divided metal powders in suspension in air are potential explosion hazards, and causes for ignition of such dust clouds are numerous [Hartmann and Greenwald, Min. MetaU., 26, 331 (1945)]. Concentration of the dust in air and its particle size are important factors that determine explosibility. Below a lower limit of concentration, no explosion can result because the heat of combustion is insufficient to propagate it. Above a maximum limiting concentration, an ejq)losion cannot be produced because insufficient oxygen is available. The finer the particles, the more easily is ignition accomplished and the more rapid is the rate of combustion. This is illustrated in Fig. 20-7. 

Validated models or strategies to assess or identify chemical or physical factors that induce autoimmune diseases are not available (see also chapter 10). Despite the fact that methods (e.g. detection of autoantibodies, histopathology) exist that could be used in a general 28-day toxicity study, potential autoimmunogenicity is usually missed. Nevertheless, any sign of inflammation in any of the animals in a 28-day study should be regarded as an alert of hazard. A chemical that produces elevated autoantibodies in experimental animals or exacerbates autoimmune disease in autoimmune-prone animals (i.e. increases severity of disease or lessens time to occurrence) is also of concern because of its potential to cause autoimmunity in humans. This is because the molecular and cellular events responsible for autoimmune disease are similar in experimental animals and humans. However, at this time, it is not possible to determine the predictive value of these models. The assumption that, for chemical-induced autoimmunity, humans are at least as sensitive as animals is a conservative estimate of sensitivity. 

Another use for computers in safety is modeling. Most common is modeling of processes and the hazards the processes create. Modeling allows people to anticipate what might happen or understand what did happen. The accuracy produced by a model depends on the availability of accurate data, the inclusion of factors that can affect the phenomenon and adequate representation in the mathematical manipulations. There are reasonably successful models in safety for automobile accident reconstruction, for gas dispersion, and for fire behavior in small buildings. Some software allows users to construct a model of a unique... 

Dose is the number one factor in toxic effect determinations. From statistically treated dose-response data, the dose (in mg/kg body weight) killing 50% of the sample population is designated as the median lethal dose (MLD or LD50). However, one should keep in mind that, LD50 values may not accurately reflect the full spectrum of toxicity or hazard all the time, because some chemicals with low acute toxicity may have carcinogenic (or endocrine) effects even at very low doses that produce no evidence of acute toxicity at all. 

Identify the Hazards. A frame of thinking should be adopted that gets to the bases of causal factors, which are hazards. These questions should be asked What are the aspects of technology or activity that produce risk What are the characteristics of things or the actions or inactions of people that present the potential for harm. Depending on the complexity of the hazardous situation, some or all of the following may apply ... 

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