Assessing Volatile Organic Compound Emissions from Passive Indoor Laundry Drying: Experimental Evidence and Health Gaps

This work examines how passive laundry drying alters indoor air quality by targeting volatile organic compound (VOC) emissions released from detergents specifically. In a controlled 40 m3 experimental chamber, VOC emissions are quantified throughout passive drying of cotton laundry cleaned with four detergent categories: conventional supermarket and ecolabeled products, each in liquid and powder formulations. Liquid–liquid extractions reveal significant variations in VOC patterns between detergents, with supermarket liquid detergents showing the broadest diversity (91 VOCs). Full-scale drying experiments have shown that the composition of the detergent only partially determines the nature of the VOCs emitted as chemical transformations occur during the laundry process. Emission dynamics vary by detergent type: supermarket products produce higher, short-term peaks (≤12 h), while ecolabeled detergents generate lower but more sustained emissions (up to 24 h). Emission levels of supermarket detergents in liquid format exceed 500 μg m–3 (toluene equivalent), dominated by alcohols, esters, and terpenoids. Toxicological screening showed that many emitted VOCs lack health reference values, limiting risk assessment. Nevertheless, according to French product rating methodologies, all tested detergents received the most penalizing health scores, highlighting potential concerns already at the detergent level. Overall, the study identifies indoor laundry drying as a recurrent VOC source and underscores the need for real-scale experimental approaches in consumer product evaluation. It also calls for the development of health benchmarks tailored to indoor exposure scenarios, to better guide safe product use and household practices.