The use of the term “microfiber” in the context of environmental pollution is a source of ambiguity, AATCC has undertaken the initiative to develop definitions for fiber fragment and microfiber. Although there are still many questions regarding fiber fragments that occur, specifically in water, in the environment, textile industry stakeholders determined the development of a standard method for quantifying shedding propensity of fabrics was needed. Degradability, chemical toxicity, and physical hazards are other important components of the shedding of textiles and will need additional test method development. As research continues, some testing parameters may be revised to improve reproducibility and relevance of the method. Options are offered where best practices are not yet defined. This test determines the mass of fiber fragments released in an accelerated laundering testing machine. Accelerated laundering is expected to provide a relative approximation of fiber fragment release in full-scale home laundering, but an exact correlation has not been determined. This test is applicable to textiles that are expected to withstand home laundering.