Adoucissant

Adoucissant is a French term that translates to softener or softening agent. In general, it denotes a substance or product designed to make something softer, more pliable, or less harsh.

Common usage is in household laundry. An adoucissant, or fabric softener, is a conditioning product added during the rinse cycle to fibers. It typically contains cationic surfactants, such as quaternary ammonium compounds, which adhere to fabric fibers to reduce static, impart a soft feel, and often provide fragrance. Some formulations claim benefits for easier ironing, though they may reduce absorbency on certain fabrics like towels over time.

Industrial applications include water treatment, where softening refers to processes that reduce water hardness by removing calcium and magnesium ions, commonly via ion exchange or precipitation. In polymer science, an adoucissant is a plasticizer, a substance added to polymers to increase flexibility and decrease brittleness by lowering the glass transition temperature.

Safety and regulation vary by region. Adoucissants may include fragrance chemicals, preservatives, and solvents; product labels typically note any skin sensitivity considerations and environmental impact. Users should follow manufacturer instructions to avoid adverse effects and to optimize compatibility with materials, surfaces, or processes being treated.

See also: fabric conditioner, water softener, plasticizer, softening agent.