I draw upon the dynamic capability model to explore how new process standards influence the ability of manufacturing facilities to improve environmental performance by reducing toxic emissions. The process standards studied are the ISO 14001 environmental management standards, in use since 1996. Hypotheses are developed to account for how early adoption of ISO 14001 and experience with the standards influence emission levels. These hypotheses are tested using a large sample of electronics manufacturing facilities and data from 1996 through 2001. Consistent with theoretical expectations, analyses show that being one of the first facilities to adopt ISO 14001 was associated with lower emissions. Further, a separate effect is due to experience: the longer a facility operated under ISO 14001, the lower its emissions. The paper discusses the implications of these results for theory and policy.