ABSTRACT
The fact that asthmatic reactions may be induced and elicited by low and, on occasion, extremely low concentrations of a given substance has given occupational asthma (OA) its own place in industrial hygiene, where the classical notions of time-weighted average (TWA) exposure, short-term exposure limits (STEL), and ceiling limits have been treated as more or less irrelevant. In the case of OA, emphasis has been laid on the identification of the causative agents and subsequent hygiene control so that subjects with OA are no longer exposed to the causal agent (1-3).
