Quats found in nearly all childcare center dust samples

Our peer-reviewed study finds quaternary ammonium compounds in at least 95% of samples, with toddlers facing high estimated exposure through indoor dust

Quaternary ammonium compounds, known as QACs or “quats,” are chemicals commonly used in disinfectants, cleaning products, personal care products, and textiles. Research links exposure to quats with immune system effects, reproductive harm, and impacts on metabolism.

In this 2025 peer-reviewed study published in the Journal of Hazardous Materials Letters, Toxic-Free Future researchers collaborated with scientists at Emory University and the Southern University of Science and Technology to investigate quat contamination in childcare centers. Researchers collected dust samples from eight childcare facilities in Seattle, Washington, and West Lafayette, Indiana, and measured the levels of quats present in indoor dust. 

The study found quats in at least 95% of samples. Concentrations of quats in dust were up to four times higher in the present study compared to what was previously reported in studies on residential indoor dust in the United States. They were also higher than levels reported from studies in China and Belgium.

Because young children frequently put their hands and objects in their mouths, indoor dust can be an important source of chemical exposure. Researchers estimated that toddlers in childcare settings may be exposed to significantly higher levels of quats through dust ingestion than adults are exposed to in their homes.

These findings add to growing evidence that harmful chemicals from everyday products are accumulating in the places where children live, learn, and play. They underscore the need for stronger policies that prevent toxic chemicals from entering products in the first place, increase transparency about chemical ingredients, hold polluters accountable, and accelerate the transition to safer alternatives.