Overview
EN ISO 25424:2019/A1:2022 is the CEN-endorsed amendment to ISO 25424, addressing sterilization of health care products using low temperature steam and formaldehyde. The amendment updates requirements for the development, validation and routine control of sterilization processes for medical devices. It clarifies the scope of application, links to EU medical device regulations, and references key microbiological, biological and chemical indicator standards used in process qualification and routine monitoring.
Note: users should confirm the current publication/endorsement status with their national standards body or the CEN website.
Key topics and technical requirements
- Process development and validation: requirements for designing and validating a low-temperature steam/formaldehyde sterilization cycle so that treated devices are safe and perform as intended after sterilization.
- Routine control and monitoring: expectations for cycle monitoring, use of biological and chemical indicators, and ongoing control to demonstrate continued process performance.
- Microbiological considerations: alignment with microbiological methods and sterility test principles (references include ISO 11737‑1 and ISO 11737‑2) for establishing microbial load and sterility test protocols.
- Indicators and acceptance criteria: normative linkage to biological indicator standards (ISO 11138 parts) and chemical indicators (ISO 11140‑1) for process qualification and routine checks.
- Regulatory alignment and risk management: annexes explain how the standard supports conformity to EU Regulations 2017/745 (medical devices) and 2017/746 (IVDs). Risk management references must be consistent with those Regulations.
- Limitations: the standard focuses on attainment of a specific microbial state by low temperature steam and formaldehyde; it does not cover device packaging design for maintenance of sterility during transport/storage or unrelated manufacturing aspects.
Applications and who uses it
- Medical device manufacturers performing sterilization process development and validation for devices sensitive to higher‑temperature methods.
- Sterile processing departments, contract sterilization service providers and validation engineers setting up or auditing low‑temperature steam & formaldehyde cycles.
- Quality assurance, regulatory affairs and compliance teams demonstrating conformity with EU General Safety and Performance Requirements.
- Test laboratories and indicator manufacturers implementing and interpreting biological and chemical indicator results for process qualification.
Related standards (normative references)
EN ISO 25424:2019/A1:2022 is essential guidance for stakeholders involved in validation and routine control of low‑temperature steam/formaldehyde sterilization, helping ensure safe, reproducible sterilization of temperature‑sensitive medical devices.
