The Clean Air Toolbox team is a core member of the science team for the Clean Air Catalyst (CAC) (Twitter: @CleanAirCAC). CAC is a major USAID-funded project working towards cleaner air in Jakarta, Indonesia, Indore, India, and Nairobi, Kenya. The lead organizations are the World Resources Institute and the Environmental Defense Fund. This project brings together experts and practitioners from around the world with local teams and stakeholders to: advance the shared awareness of air pollution sources; collect, analyze and share data; and design targeted interventions via political and social analysis. Current Clean Air Toolbox activities within CAC include advising local teams on source apportionment and personal exposure monitoring study design, analyzing satellite data, political analysis, conducting capacity-building activities for USAID, and managing the creation of the source awareness data collection plan.