Yanan Zhan, Dan Dan Huang, Hongli Wang, Yaqin Gao, Yingjie Li, Shuhui Zhu, Qianying Liu, Jing Duan, Lu Yang, Wei Xu, Haobin Zhong, Liyuan Zhou, Yong Jie Li, Cheng Huang, Qingyan Fu, Thorsten Hoffmann, Ru-Jin Huang; Formation Kinetics and Yields of Secondary Organic Aerosol from Benzothiazoles Based on Oxidation Flow Reactor and Ambient Studies. Environ. Sci. Technol. Lett. 14 October 2025; 12 (10): 1366–1372. https://doi.org/10.1021/acs.estlett.5c00714      

      Benzothiazoles (BTHs) are an important class of emerging organic pollutants from volatile chemical product emissions which have been detected in atmospheric environments due to their extensive use, especially as vulcanization accelerators in tire production. However, studies of the atmospheric photochemical oxidation of BTHs remain very limited, hindering the assessment of their atmospheric impacts. Herein, we systematically investigated the reaction kinetics and yields of secondary organic aerosol (SOA) from benzothiazole (BTH, the parent compound of BTHs) photo-oxidation under various experimental conditions using an oxidation flow reactor. The rate constant for BTH reacting with OH radicals, (3.14 ± 0.20) × 10^–12 cm³ molecule^–1 s^–1, was similar to that of single-ring aromatics like toluene, yet its SOA yield was comparable to that of bicyclic aromatics like naphthalene. Furthermore, we found that while NOx suppressed the BTH-derived SOA production, relative humidity enhanced its production. Further field measurements revealed significant SOA formation potential from BTH photo-oxidation in typical urban areas, comparable to that of well-known benzene or naphthalene. Gaseous BTH in an offshore atmosphere was also detected, indicating its potential impacts on marine environments. Our results elucidate the atmospheric photochemical processes of BTH, revealing its important but previously overlooked contribution to ambient SOA formation.