Fig. 1. Simplified scheme for VOC ozonolysis and radical cycling leading to indoor SOA formation.

Letters in red circles correspond to panel labels in Fig. 2, letters in blue circles correspond to panel labels in Fig. 3, letters in green circles correspond to panel labels in Fig. 4, and numbers in gray circles correspond to figure numbers in the Supplementary Materials. HOMs, highly oxygenated organic molecules; NCA, nanocluster aerosol; OVOC, oxygenated VOC; hv, light.