The California OSHA Airborne Contaminant Advisory Committee reviewed several hundred substances and recommended occupational exposure limits with the intent of worker and employer protection. The model used offers important benefits. First, by allowing open meetings, the process was transparent, and input could be offered by concerned stakeholders. Second, the process was data-driven and, therefore, less susceptible to bias and error. Third, by incorporating members with backgrounds in toxicology, epidemiology, risk assessment, occupational medicine, and industrial hygiene, the process fostered a thorough and diverse assessment of substances.