Exposure toxicity

Personnel Selection and Training. The quaHty of operating personnel is of paramount importance to the safe operation of a chemical plant. Operators must be intelligent and emotionally stable. Excessive use of alcohol and dmgs affects reHabiHty and can thereby render workers more susceptible to certain types of toxic exposure. Thorough medical screening is essential to avoid damaging exposures to susceptible individuals, eg, people with respiratory ailments should not be employed in areas where corrosive atmospheres could occur. 

Those illnesses that occur directly after a distinct toxic exposure are usually identified as being environmentally or... 

Exposure by inhalation The toxic exposure of the body due to breathing contaminated air. 

The 50% value is generally chosen because it represents the response of the average organism to the toxic exposure, thus providing the greatest predictive ability. 

Feldman RG, White RF, Currie JN, et al. 1985. Long-term follow-up after single toxic exposure to trichloroethylene. Am J Ind Med 8 119-126. 

The acceptable limits for toxic exposure depend on whether the exposure is brief or prolonged. Lethal concentration for airborne materials and lethal dose for non-airbome materials are measured by tests on animals. The limits for brief exposure to toxic materials that are airborne are usually measured by the concentration of toxicant that is lethal to 50% of the test group over a given... 

Toxic exposure data for 1995, compiled from 67 poison control centers, indicated that there were 1,407 (1,400 unintentional) hydrogen sulfide exposures during that year (Litovitz et al. 1996). None of these individuals died and the vast majority of these exposures resulted in outcomes that were either minor or nonexistent. Approximately 34% of the exposed individuals were treated in a health care facility (Litovitz et al. 1996). 

Donham KJ, Knapp LW, Monson R, et al. 1982b. Acute toxic exposure to gases from liquid manure. J OccupMed 24 142-145. 

Litovitz T, Felberg L, White S, et al. 1996. 1995 annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System. Am J Emerg Med 14 487-494, 521. 

Osbem LN, Crapo RO. 1981. Dung lung A report of toxic exposure to liquid manure. Arm Intern Med 95 312-314. 

The analysis methods are national in scope and address emissions from a wide variety of industrial and community source types. The materials reviewed are of widely disparate natures. They include metals, and bulk and trace hydrocarbons, including chlorinated and oxide derivatives of hydrocarbons. The analyses are intended to be preliminary screening analyses for use in scoping and prioritizing regulatory attention to toxic exposures from the chemicals studied. 

For each category of land or water body use, one may envision a simplified scenario. In each scenario, only those activities most likely to lead to toxic exposures are considered. For example, In the Industrial scenario, Indoor workers would not be exposed to levels of dust bearing high concentrations of soli contaminants outdoor workers who stir up dry soli with heavy machinery, however, could expect to Inhale contaminant-laden dust. A scenario could Involve more than one exposure pathway. Thus, the Industrial worker might drink water from a contaminated well, In addition to breathing contaminated dust these exposures might represent not only different pathways but different sources. 

Grabo TN. 1997. Unknown toxic exposures. Arts and crafts materials. Aaohn Journal 45(3) 124-130. 

Dubitski (1911) (as cited in Flury and Zernik 1931) noted that the dog was similar to the cat regarding arsine toxicity. Exposure to 10 ppm was without... 

The following factors have been suggested as alternatives to consider when presented with a potential case of exposure to carbon monoxide diabetic ketoacidosis, hypothyroidism and myxedema coma, labyrinthitis, and lactic acidosis toxic exposures resulting in methemoglobinemia ingestion of alcohols or narcotics and diseases that cause gastroenteritis, encephalitis, meningitis, and acute respiratory distress syndrome. 

Phillips, L.J. and G.F. Birchard. 1990. An evaluation of the potential for toxics exposure in the Great Lakes region using Store data. Chemosphere 20 587-598. 

Table 2-2 lists some of the effects or responses from toxic exposure. 

Changes in skin texture, pigmentation, vascularity, and hair and nail appearance are indicative of possible toxic exposures. 

Blood counts are also used to determine toxic exposures. Measurements of the red and white blood cells, hemoglobin content, and platelet count are performed easily and inexpensively. However, blood counts are frequently insensitive to toxic exposure marked changes are seen only after substantial exposure and damage. 

Hanson D. 1993. OSHA won t appeal toxics exposure ruling. Chemical and Engineering News 5. 

The calculations of the Inherent Safety Index (ISI) are made on the basis of the worst situation. The approach of the worst case describes the most risky situation that can appear. A low index value represents an inherently safer process. In the calculations the greatest sum of flammability, explosiveness and toxic exposure subindices is used. For inventory and process temperature and pressure the maximum expected values are used. The worst possible interaction between chemical substances or pieces of equipment and the worst process structure give the values of these subindices. 

---