We are very proud of Timothy’s work, titled “Impact of glycol-based solvents on indoor air quality—Artificial fog and exposure pathways of formaldehyde and various carbonyls”, just published in Indoor Air (Link). A big congratulations to Timothy, Tolu, and Chester, who contributed to this work. Artificial fogs are commonly used in the entertainment and theatric industries to create special visual effects. Artificial fogs are made by heating a ‘fog juice’, which contain triethylene glycol and water. Although the risk of glycol inhalation has been implied, there has been no systematic study on how artificial fogs can affect indoor air. In our work, we monitored the particles arising from a fog machine, as well as the chemicals present in those particles. Surprisingly, we found a high concentration of carbonyls, including formaldehyde, from the fog juice. We hypothesized that autooxidation of triethylene glycol during storage is likely the source. This study presents a significant implication to stage actors, workers in the entertainment industry, and consumers of artificial fogs.