Regulatory agencies in Japan, US and EU have been requiring validation for sterilizing filtration as part of aseptic processing to pharmaceutical industry. ISO 13408 offers guidance to filter users concerning general requirements for set up, validation and routine operation of a sterilizing filtration process, to be used for aseptic processing of health care products. ISO/TC 198/WG9 has been working for definition of requirements for filter selection, fluid specific selection criteria, filtration process, system design, routine process, documentation, maintenance &change control and operator training. At present, it is a step of Draft International Standard.