AATCC M7-1991, Standard Laboratory Practice for Home Laundering Fabrics Prior to Flammability Testing to Differentiate Between Durable and Non-Durable Finishes, sets out a laundering routine applied to specimens before flammability testing so that a durable finish can be told apart from one that washes out. It defines the wash conditions, detergent and drying steps to be used, and how the treated specimens are handled before testing. The practice is used by textile laboratories and finishers assessing the persistence of flame retardant treatments.