•   Seven antimicrobials were extracted from 80 U.S. dust samples.
•   Parabens, triclosan and triclocarban were ubiquitous in U.S. indoor dust.
•   Triclosan levels in dust were higher in athletic facilities than in homes.
•   Study establishes antimicrobial levels in U.S. indoor dust prior to TCS and TCC ban.
•   Median estimated daily intake (EDI) was the highest for toddlers and infants.


Antimicrobials in indoor dust pose concerns due to their endocrine disrupting activities and potential promotion of antibiotic resistance. We adopted dispersive solid phase extraction (d-SPE) and liquid chromatography-tandem mass spectrometry (LC–MS/MS) to quantify antimicrobials in dust. The method showed favorable linearity (R2 >0.99), recovery (83–115%), and method detection limits (1.2–5.6 ng/g, dry weight). All seven analytes were found at median concentrations in ng/g in each of the 80 U.S. dust samples collected from athletic facilities and residential homes: methyl paraben (1920) > propyl paraben (965) > triclosan (390) > triclocarban (270) > ethyl paraben (195) > butyl paraben (80) > benzyl paraben (6). Triclosan levels in dust from athletic facilities were significantly higher than those in private homes (p < 0.05). Median estimated daily intake (EDI) of antimicrobials in ng/kg-body weight/d from dust ingestion was lowest for adults (1.9) and higher for more sensitive subpopulations, including infants (19.8), toddlers (23.6), children (11.8) and teenagers (4.6). This first application of d-SPE to the analysis of dust produced U.S. baseline data for triclosan and triclocarban levels in indoor dust just prior to the 2017 Federal ban on use of these trichlorinated aromatics in antiseptic soaps and related personal care products.