Keeping beryllium workers safe: an enhanced preventive model.

I n the late 1990s, leaders in a company that manufactures beryllium materials began a process to re-examine the effectiveness of the existing beryllium safety model. This model was based on the primary goals of keeping worker exposure below 2 μg/m3 time-weighted average (TWA) as determined by the daily weightedaverage (DWA) method and prevention of beryllium migration to home and the community. The company initiated a series of medical surveillance projects, partnering with independent academic and government institutions. The response to findings of patterns of subclinical chronic beryllium disease and beryllium sensitization as measured by the beryllium blood lymphocyte proliferation test was the continuation of traditional process isolation and ventilation engineering to improve air level control. Additional medical surveillance suggested that the efficacy of this approach was limited. An enhanced safety model was evolved that included very strict control of respiratory exposure, reduction of skin exposure, and migration control at three levels: process, work area, and plant boundaries; maintenance of workplaces in clean and shipshape condition; and worker education. Rather than prioritize with a strict hierarchy of controls, a multifaceted approach to worker protection was adopted, using the slogan “Protect people first, then solve the problem.” Concepts of statistical process control, usual and special variation, were adapted to respiratory protection management and integrated with AIHA exposure guideline tools. The rate of beryllium sensitization in new employees hired after implementation of the enhanced beryllium safety model was substantially reduced compared with its prevalence in the prior surveys. Because the company implemented multiple changes in a short time, the contribution of individual components of the model cannot be estimated.