Scented Cleaning Products Form Lung-Reaching Nanoparticles Within Minutes

Cleaning a countertop or mopping a floor may create an invisible cloud of particles within minutes, according to research led by Purdue University indoor-air-quality scientist Brandon Boor. In experiments conducted inside a small model house on Purdue’s campus, researchers tested conventional scented cleaners as well as botanical disinfectant sprays and wipes. The products released fragrance compounds known as terpenes, including pinene, limonene, thymol and linalool. When those compounds reacted with ozone in the indoor air, they formed large numbers of nanoparticles. The particles were mostly between 1 and 30 nanometers wide—a size range that many consumer air-quality monitors do not detect. Depending on the product and cleaning activity, the team recorded billions or trillions of particles. The researchers said the concentrations exceeded outdoor levels measured during the experiments. Because of their small size, the particles can travel through the airways and deposit deep in the lungs. The source report says they may contribute to respiratory irritation and inflammation and could potentially enter the bloodstream, although the experiment measured particle formation rather than establishing specific health effects in people. Boor compared the estimated respiratory dose from the indoor particles with, and in some cases above, the dose associated with standing beside a busy road. The particles differ in composition from roadside pollution, however. Their presence may also be difficult to notice because they do not create visible smoke, dust or haze; instead, the room may simply smell clean. The researchers also examined the effect of germicidal far-UV lamps. Those lamps interacted with oxygen and raised ozone concentrations in the model house to roughly 20 to 40 parts per billion. When scented cleaning products were used at the same time, the combination of higher ozone and concentrated fragrance compounds produced even more particle formation. The team recommends choosing low-fragrance or fragrance-free products, avoiding several scented products during one cleaning session, ventilating with exhaust fans or open windows, and not using ozone-generating devices while cleaning with scented products. The findings were scheduled for presentation at the American Chemical Society’s fall meeting.