Dermally induced respiratory

Dihydroxybenzenes (DHBs) are slightly more acutely toxic than phenol (Table 5). Contact with dihydroxybenzene through oral, dermal, or respiratory routes can induce significant systemic exposure. Skin or eye effects have been demonstrated during chronic or accidental professional exposure. No systemic effect has been described in such circumstances. 

Most OEL-setting organizations also establish qualitative notations to indicate the ability of a compound to induce dermal or respiratory sensitization. This approach is used since dose-response thresholds for the induction of these sensitization responses are generally not well understood, and sensitized individuals may respond to very low exposure... 

Sensitizer. A chemical that causes vulnerable, exposed individuals to develop a respiratory allergic reaction following repeated exposure. Methylene bisphenyl isocyanate, toluene diisocyanate, and trimellitic anhydride are examples of respiratory sensitizers. It should be noted that sensitizing chemicals that are inhaled have the propensity to also induce dermal sensitization and that skin exposure to sensitizers (e.g., ammonium thioglycolate) can induce respiratory sensitization. Such cross-sensitization is discussed below and in Chapter 29. 

Inhalation of sensitizing chemicals can lead to dermal sensitization, and dermal absorption of sensitizing chemicals can lead to respiratory sensitization. Airway exposure to toluene diisocyanate has been shown to induce dermal sensitization, I23l and dermal application of trimellitic anhydride has been shown to induce respiratory sensitization in test animalsJ24-26 These results are consistent with the understanding that both respiratory and dermal sensitization are associated with IgE responses. 

Death. No studies were located regarding death in humans after inhalation or dermal exposure to disulfoton. One case report of human death after acute oral exposure to disulfoton was found (Hattori et al. 1982). Because an unknown amount was ingested, the lethal dose was not determined. Autopsy results suggested that death may have been due to asphyxia resulting from respiratory failure. Pulmonary edema is associated with disulfoton-induced overstimulation of secretory glands and bronchial secretions in the respiratory tract. 

Ocular Effects. Acute exposure to diesel fuel induced ocular effects in one case (Barrientos et al. 1977). Subconjunctival hemorrhages occurred in a man who had washed his hair in an unknown amount of diesel fuel. Effects resulting from inhalation versus dermal exposure could not be distinguished in this case. Eye irritation was also noted in factory workers who were chronically exposed to jet fuel (Knave et al. 1978). The limitations of this study are discussed in detail in Section 2.2.1.2 under Respiratory Effects. 

Substances, which are skin or eye irritating or corrosive after single exposure (Section 4.5) should be suspected of inducing local effects upon repeated respiratory exposure to low concentrations. In contrast, local effects reported from skin sensitization studies as well as dermal repeated dose toxicity studies are not predictive of local effects on the respiratory tract. In addition, observations from irritation and/or sensitization studies as well as repeated dose inhalation toxicity studies are not predictive of local effects on the skin upon repeated dermal exposure (EC 2003). 

TMA is a volatile aliphatic tertiary amine with a pungent odour resembling rotting fish (Fig. 7.4.1). TMA has a 100-fold greater olfactory potency than its N-oxide. The reported threshold odour for TMA is 0.9 ppm. Exposure to concentrations above 20 ppm gives moderate irritation of the respiratory system and the eyes. Dermal contact with a concentrated aqueous solution may cause severe burns [4]. Oral ingestion of 15 mg TMA hydrochloride/kg body weight induces nausea and ichthyo-hydrosis [9]. 

Inhalation exposure to toluene diisocyanates is irritating to the eyes and respiratory tract, and induced chronic rhinitis, interstitial pneumonia and catarrhal bronchitis after long-term exposure. Respiratory sensitization to toluene diisocyanate developed in guinea-pigs after inhalation but also after dermal exposure (lARC, 1986). 

As indicated in Table 7.6, all hazardous chemicals in electric arc furnace dust are assumed to induce deterministic responses. The possible responses include renal toxicity, effects on the cardiovascular system, dermal or ocular effects, decrease in body weight, hepatic toxicity, and respiratory toxicity. Decrease in body weight is not a response in a particular organ but is assumed to be a health effect of concern. All deterministic responses are assumed to be induced by more than one chemical in the waste. Furthermore, some of the chemicals (barium, beryllium, chromium, and lead) are assumed to induce all responses. 

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