The standard specifies performance requirements and test methods for chemical indicators intended for use with various sterilization processes. The requirements for specific test indicators (such as Bowie-Dick test indicators and indicator systems) are covered in other parts of the series of standards. An essential aspect which has led to the revision of the standard is the desire for clarification that the described indicator classes are not subject to a hierarchy. Based on the motto "the higher the class, the better the indicator" which was often used as a marketing tool by some manufacturers. A categorisation in accordance with the intended use of the indicators has been introduced in order to provide the user in health care with criteria for determining which indicator type for which application is needed. The International Standard has been prepared by ISO/TC 198 "Sterilization of health care products" (secretariat: ANSI, USA) in collaboration with CEN/TC 102 "Sterilizers for medical purposes" (secretariat: DIN, Germany). The national responsible body is Working Committee NA 063-04-08 AA "Indikatoren" ("Indicators") at DIN Standards Committee Medicine (NAMed).