According to BSI,
http://www.bsiamericas.com/MedicalDevices/Updates/011007.xalter,
The three main harmonized European sterilization standards (EN 550, EN 552 and EN 554) are in the process of being re-issued to become EN ISO standards. Their ISO counterparts (ISO 11135, ISO 11137 and ISO 11134 respectively) are similarly being replaced by these new EN ISO standards.
The new standards follow a common format based on EN ISO 14937:2000. They provide consistent definitions and use common quality system elements based on reference to ISO 13485:2003.
EN 552 has already been re-issued as EN ISO 11137:2006. It is in 3 parts: Part 1 covers the requirements, Part 2 covers the methods that can be used for establishing the sterilization dose, and Part 3 covers guidance on dosimetric aspects. Changes include the introduction of a rational approach to dose auditing and a new VDmax method for substantiating a minimum dose of 15 kGy.
EN 554 has already been re-issued as EN ISO 17665. It is in 2 parts: Part 1 (issued 2006) covers the requirements while Part 2 covers guidance. It consolidates EN 554, ISO 11134 (industrial moist heat sterilization) and ISO 13683 (moist heat sterilization in health care facilities) into a single standard to cover the moist heat processes used in the Medical Device, Pharmaceutical and Health Care sectors. Part 2 is not expected to be published until early in 2008.
EN 550 is due to be re-issued as EN ISO 11135 this year (not yet issued). It will be a single standard but will be supported by a guidance document in the form of a Technical Specification. Potential changes include a clear requirement for at least 3 physical performance qualification runs, a clear requirement for periodic re-qualification of the sterilization process, and the option to use the half cycle method validation approach when parametric release is selected.
Compliance with EN 550, EN 552 and EN 554 provides a presumption of conformity with the applicable Essential Requirement of the Medical Devices Directives. There will be a 3 year transition period during which time EN 550, EN 552 and EN 554 will remain valid and can still be used to demonstrate conformance with Essential Requirements.
EN 552 will be withdrawn at the latest by April 2009.
EN 554 will be withdrawn at the latest by August 2009.
EN 550 will be withdrawn after a 3-year period following the issue of EN ISO 11135.
Therefore, using irradiation sterilization as an example, during the transition period manufacturers can use either EN 552 or EN ISO 11137 to demonstrate conformance with Essential Requirements. The ISO counterpart (in this case ISO 11137) is also acceptable.
Contract sterilization companies normally wish to demonstrate compliance with the applicable sterilization standard via their ISO 13485 registration.