Do EASE scenarios fit workplace reality? A validation study of the EASE model. Estimation and Assessment of Substance...

Within the framework of European risk assessment of new and existing substances, the EASE model (Estimation and Assessment of Substance Exposure) is often applied to assess inhalative exposure at workplaces. To contribute to the validation of this model, single EASE scenarios were compared with independent measurement data on inhalative exposure to vapors and dusts. For this purpose, workplace measurements obtained in the areas of production, textile printing and coating, screen printing and offset printing, the rubber industry, and the plastics processing industry as well as flame spraying were used. A good correspondence between model estimates and measurement data was found in the case of exposure to vapors for the production of chemical substances in closed systems (EASE scenario: closed system without breaching) and for procedural control works at mainly automated printing workplaces (EASE scenarios: non dispersive use, segregation, low/medium volatility). For the handling of powdery substances measurement results obtained during weighing and filling works, in part semiautomatic, were compared with the EASE estimates for the scenario: dry manipulation, with/without local exhaust ventilation. Good correspondence was estimated if approx. 1 t to 200 t powdery substances were handled per shift. For the EASE scenarios "direct handling with natural ventilation/with local exhaust ventilation," high discrepancies exist between model prediction and measurement results obtained during manual screen printing or the preparation of printing inks.