RESPIRATORY ALLERGY - HAZARD IDENTIFICATION AND RISK ASSESSMENT

Various chemicals and proteins of industrial importance are known to c ause respiratory allergy, with occupational asthma being the most impo rtant manifestation of the disease. This paper describes clinical synd romes, mechanisms associated with occupational respiratory hypersensit ivity, and methods available currently for the prospective identificat ion of potential respiratory allergens. Certain classes of chemicals a re commonly associated with occupational respiratory allergy. There is insufficient information, however, to predict respiratory sensitizati on potential from analysis of structure alone, although reactivity wit h proteins is likely to be relevant. As yet there exist no fully valid ated or widely applied predictive methods or internationally harmonize d guidelines. The most promising predictive animal methods are the mou se IgE test and guinea pig models. Work in mice has focused upon event s occurring during the induction phase of sensitization following prim ary encounter with the test chemical. In contrast, guinea pig models h ave been used primarily to identify respiratory allergens (chemicals o r proteins) as a function of elicitation reactions induced in previous ly sensitized animals. Given the possible serious health manifestation s of respiratory allergy, early identification of respiratory sensitiz ers is urgently required. The two methods should, as a priority, be de veloped further and the production of a detailed protocol for these me thods be undertaken to facilitate further validation. Together, this i nformation will allow for two types of risk assessment associated with respiratory allergy: the risk that exposure to a material will (1) in duce sensitization in an individual and (2) elicit allergic reactions in a previously sensitized individual. (C) 1994 Society of Toxicology.