Scented Dryer Sheets

Dryer sheets work by coating fabric fibers with a thin film of softening compounds and fragrance during the heat and tumbling of the drying cycle. The polyester substrate acts as a carrier; as the dryer heats up, the chemical coating melts and deposits onto everything in the drum. This is an efficient delivery mechanism for softness and scent — and also for the chemical concerns that accompany both.

The softening agents on most dryer sheets are quat-based compounds — the same quaternary ammonium chemistry used in liquid fabric softeners and disinfecting wipes. These compounds deposit on fabric and remain in contact with skin. People with reactive airways, eczema, or fragrance sensitivity often identify dryer sheets as a trigger before they identify any other laundry product, because the heat-activated delivery puts a large concentration of these compounds directly onto clothing and bedding.

Synthetic fragrance on dryer sheets is among the most concentrated of any laundry product by the nature of the format. A single sheet is designed to perfume an entire load of laundry. The fragrance blend includes volatile organic compounds that continue to off-gas from clothing throughout the day — this is the mechanism behind the "fresh laundry smell" that persists for days after washing. From an exposure standpoint, that persistent volatilization is continuous inhalation of fragrance chemicals.

For households trying to reduce chemical exposure, dryer sheets are one of the easiest swaps to make. Wool dryer balls handle static mechanically — by separating fabrics and absorbing and releasing moisture during the cycle — with no chemical deposit. Dryer balls also reduce drying time by improving air circulation, which is a secondary benefit entirely unrelated to chemistry.