We investigate the emergence and growth of “green chemistry”—an effort by chemists to encourage other chemists to reduce the health, safety, and environmental impacts of chemical products and processes—to explore how occupational members, absent external triggers for change, influence how their peers do their work. Using extensive interviews, archival data, and observations, we find that advocates simultaneously advanced different frames that specified the utility of making the change: (1) a normalizing frame, positioning green chemistry as consistent with mainstream chemistry innovation; (2) a moralizing frame, positioning it as an ethical imperative; and (3) a pragmatizing frame, positioning it as a tool that could help chemists tackle problems they encountered in their day-to-day work. Each frame resonated differently with chemists in their various occupational roles. Though this pluralistic approach generated broad acceptance of the change effort, it also exposed tensions, which threatened the coherence of the change. Advocates’ diverse responses to these tensions contribute to a persistent state of pluralism and dynamism in the change effort. We uncover a process through which occupational members generate and sustain change, show how occupational heterogeneity can enable and delimit change, and show how well-meaning efforts to “moralize” occupational work can heighten resistance, inhibiting the very changes that enable experts to address urgent societal problems.