ISO 23611-3:2007 specifies a method for sampling, handling and extracting enchytraeids from terrestrial field soils as a prerequisite for using these animals as bioindicators (e.g. to assess the quality of a soil as a habitat for organisms). It applies to all terrestrial biotopes in which enchytraeids occur. ISO 23611-3:2007 is not applicable for semi-terrestrial soils and might be difficult to use under extreme climatic or geographical conditions.