Chemical free or chemical-free is a term used in marketing to imply that a product is safe, healthy or environmentally friendly because it only contains natural ingredients. From a chemist's perspective, the term is a misnomer, as all substances and objects are composed entirely of chemicals and energy. The term chemical is roughly a synonym for matter, and all substances, such as water and air, are chemicals.
This use of the term chemical free in advertising to indicate that a product is free of synthetic chemicals, and the tolerance of its use in this fashion by the United Kingdom's Advertising Standards Authority, have been the subject of criticism.
A study of understandings of the term chemical among American undergraduates by chemist Gayle Nicoll in 1997 noted that "People may hold both a scientific and layman's definition of a chemical without linking the two together in any way. They may or may not consciously distinguish that the term 'chemical' has different connotations depending on the situation."