This study examines how the COVID-19 pandemic disrupted established expertise, triggering the emergence of new domains of expertise within the ‘Clean Air’ movement. Building on literature on social change and boundary work, we propose a production model of expertise, highlighting how crises destabilize established authority and catalyze collective efforts to produce alternative expertise. Through an in-depth exploration of coalitions advocating for clean air in Canadian schools, we identify three archetypes of expertise—scientific, functional, and experiential—each engaging in distinct practices such as aligning technical knowledge, creating standards, and assembling eclectic networks. Our findings underscore the relational and processual nature of expertise, revealing how academic, professional, and layperson groups converge to address shared social issues, reshape boundaries, and assert new forms of authority. By situating expertise within the broader context of social movements and societal change, this research advances understanding of how expertise is produced in response to a collective challenge.
