An analysis of household dust shows an increase in levels of quaternary ammonium compounds, or quats, this year compared with 2018 and 2019 (Environ. Sci. Technol. Lett. 2020, DOI: 10.1021/acs.estlett.0c00587). Quats, such as alkyldimethylbenzylammonium chloride (ADBAC), are disinfectants found in many consumer cleaning products that the US Environmental Protection Agency suggests could be effective against SARS-CoV-2, the virus that causes COVID-19. But studies in mice have linked quats to reproductive and developmental problems, and some scientists have called for more assessment of the compounds’ safety. Guomao Zheng, Gabriel M. Filippelli, and Amina Salamova at Indiana University Bloomington used mass spectrometry to analyze dust collected in June 2020 from 40 households in Indiana and compared the data with those from previous years. They found that amounts of all quats had increased, and ADBAC levels had almost doubled. The researchers say contaminated dust may expose people to quats in the home, and more tests are needed to see if the increase in quat exposure holds true in other locations.