Ethylene Oxide Sterilization Audit Checklist (ISO 11135)
This professional audit checklist is designed for medical device manufacturers and quality auditors to evaluate Ethylene Oxide (EO) sterilization processes. It ensures full compliance with ISO 11135-1 ו ISO 13485 standards.
1. Scope
This checklist is applicable for sterilization processes for medical products carried out with ethylene oxide. For sterile products of Risk Class III, documentation of design and validation must be examined. A sterilization assessment must be carried out based on at least one product file.
2. Responsibilities and Authority
Lead Auditor
Responsible for the examination of the QM system regarding ISO 13485 and Council Directive 93/42/EWG. The lead auditor supervises the audit team and ensures DQS process compliance.
Technical Expert
Responsible for product-specific evaluation, specifically focusing on design documentation and the validation of sterilization procedures.
3. Approach to the Evaluation
The goal is to examine fulfillment of ISO 11135-1. Results must be formulated in the audit report with reference to this checklist.
| Clause | Audit Question / Requirement | Evaluation |
|---|---|---|
| 4. Quality Management Systems | ||
| 4.1 Documentation | ||
| 4.1.1 | Have procedures for the design, validation, routine control and product release from sterilization been specified? | |
| 4.1.2 | Are all documents and records according to ISO 11135-1 reviewed, approved and controlled? | |
| 4.2 Management Responsibility | ||
| 4.2.1 | Are responsibilities and authorities specified and assigned to qualified persons? | |
| 4.2.2 | Is there a contract agreement if several organizations are involved? | |
| 4.3 Product Realization | ||
| 4.3.1-2 | Are procedures for purchasing, identification and traceability specified? | |
| 4.3.3 | Is a system for calibration of all equipment and testing instruments specified? | |
| 4.4 Measurement, Analysis and Improvement | ||
| 4.4 | Are procedures for control of nonconforming product and corrective/preventive actions specified? | |
| 5. Sterilizing Agent Characterization | ||
| 5.1 | Are the composition, storage conditions and storage length specified for the EO agent? | |
| 5.2 | Is the microbicidal effectiveness worked out if non-standard compositions are used? | |
| 5.3 | Assessment of effects on the product according to Section 7. | |
| 5.4.1 | Documented environmental effect evaluations and monitoring actions? | |
| 5.4.2 | Observance of local/national regulations regarding EO emission and disposal? | |
| 6. Process and Equipment Characterization | ||
| 6.1.2 | Does characterization include preconditioning, cycle, and ventilation? | |
| 6.1.3 | Does cycle include air removal, EO addition, maintenance, and rinsing? | |
| 6.1.4 | Is (pre)treatment carried out under controlled humidity and temperature? | |
| 6.1.5-6 | Are process variables (temp, humidity, EO conc, time) specified with tolerances? | |
| 6.2.1-2 | Equipment specification documented including description of all monitoring instruments? | |
| 6.2.3 | Software evidence of correspondence with specifications (ISO 9000-3)? | |
| 6.2.4 | Does control function failure NOT affect the recording function? | |
| 7. Product Definition | ||
| 7.1.1-2 | Actions taken for new/changed products or loading configurations? Equivalence documented? | |
| 7.1.3-5 | Permeation/removal of EO in parts most difficult to sterilize proven? | |
| 7.2.1-5 | Product safety: influence of multiple sterilization, biological safety (ISO 10993), and EO residues? | |
| 7.3.1-2 | Bioburden estimation (ISO 11737-1) and cleaning efficiency evaluation (ISO 17664)? | |
| 8. Process Definition | ||
| 8.1-4 | Sterilization process specified and supported by IQ/PQ documentation? | |
| 8.5-7 | Microbial effectiveness determined (Annex A/B)? BI indicators comply with ISO 11138? | |
| 8.8-9 | Chemical indicators (ISO 11140) and sterility exams (ISO 11737-2) compliance? | |
| 9. Validation (IQ, OQ, PQ) | ||
| 9.1 Installation Qualification (IQ) | ||
| 9.1.1-6 | Equipment compliance, technical schemes, and installation site specifications established? | |
| 9.2 Operation Qualification (OQ) | ||
| 9.2.1-2 | Proof of equipment ability to perform within tolerances; calibration confirmed? | |
| 9.3 Performance Qualification (PQ) | ||
| 9.3.1-3 | Consistent function evidence, microbiological PQ, and physical PQ (3 consecutive runs)? | |
| 9.4 | Changes to loading configuration evaluated for SAL impact? | |
| 9.5.1-6 | Validation report review and approval; parametric release criteria specified? | |
| 10. Routine Monitoring and Control | ||
| 10.1 | Monitoring of temperature, pressure, humidity, EO concentration, and gas circulation? | |
| 10.2 | Parametric release: 2-point temperature measurement and direct EO analysis? | |
| 11. Product Release from Sterilization | ||
| 11.1 | Documented criteria for conformity (data records vs specification)? | |
| 11.2 | Handling of nonconforming products (ISO 13485) if variables or BI fail? | |
| 12. Maintaining Process Effectiveness | ||
| 12.1-2 | Periodic efficiency proof and preventive maintenance planning? | |
| 12.3.1-8 | Reassessment procedure (annual for parametric release); BI suitability checks? | |
| 12.4.1-3 | Assessment of changes (equipment/product/agent) and validation extent definition? | |
Disclaimer: This checklist is a guide. Always refer to the official ISO 11135:2014 standard for regulatory submissions.