Abstract

One notable statement comes from EU GMP Annex 1, paragraph 7.13, which states that cleanroom clothing used in Grade A and B areas should be sterile and should be handled in a way that prevents recontamination. In practice, this expectation means that sterility should be supported by appropriate supplier qualification, process validation and evidence that the sterilization process remains controlled. For single-use consumables, this is straightforward as they are produced, packaged and sterilized under controlled conditions by qualified vendors. However, washable garments and reusable goggles pose a major challenge.

The ISO 11137 sterilization standard — along with similar standards for moist heat, EO, or other sterilization methods — requires knowledge of the pre-sterilization bioburden to validate sterilization cycles; a parameter that cannot be consistently known for reusable items subjected to variable usage and laundering conditions. This paper examines the regulatory background, the scientific rationale for requiring validated sterility, and the technical challenges associated with reusable garments and eyewear. It concludes with practical, risk-based strategies for both suppliers and end-users to comply with Annex 1 while maintaining operational feasibility and safety.

1. Regulatory Background

1.1. EU GMP Annex 1 — Overview

EU Annex 1 of the EU Guidelines for Good Manufacturing Practice (GMP), revised in 2022 (in operation since August 2023), represents the most comprehensive update in decades to sterile manufacturing controls. Its scope emphasizes:

1. A Contamination Control Strategy (CCS) required as a central, living document
2. Validation and qualification of all contamination control measures
3. Enhanced expectations for personnel gowning and behavior in cleanrooms
4. Stronger emphasis on risk-based justification for all materials entering Grade A and B zones of cleanrooms

Paragraph 7.13 of Annex 1 explicitly states that garments worn in Grade A and B areas should be sterile and handled to prevent recontamination. The same expectation applies to facial and eye coverings, which are considered potential contamination vectors due to their proximity to the operator’s breathing zone.

1.2. “Sterile” Means “Validated Sterile”

In this context, “sterile” is generally understood to mean more than simply having been subjected to a sterilization process; it should be supported by appropriate validation and routine control.

Validation in this context means:

1. Defining a sterilization method (steam, gamma, EO, etc.)
2. Characterizing the product’s bioburden before sterilization
3. Demonstrating that the selected cycle achieves the target Sterility Assurance Level (typically 10-⁶)
4. Routinely monitoring and controlling the process to maintain performance

Thus, Annex 1 implicitly demands that sterility of clothing and eyewear be established through validated processes — the same scientific rigor expected for sterile product components.

2. Standards and Definitions

2.1. ISO 11137 — Radiation Sterilization of Healthcare Products

ISO 11137 outlines the requirements for development, validation, and routine control of a radiation sterilization process. It mandates:

1. Determination of pre-sterilization bioburden through representative sampling
2. Use of statistical methods to select dose
3. Verification of dose effectiveness via sterility testing
4. Ongoing monitoring of bioburden trends to confirm continued validity

Although ISO 11137 is written primarily for medical devices, the principles apply broadly wherever sterilization validation is required. The same applies to ISO 17665 (moist heat) and ISO 11135 (ethylene oxide) standards.

2.2. Key Implication

To validate sterilization, the anticipated pre-sterilization microbial load must be known or established. Without that data, it is impossible to statistically justify a sterilization cycle’s effectiveness in achieving the required Sterility Assurance Level (SAL).

3. The Technical Dilemma: Washable Clothing and Goggles

3.1. Unknown and Variable Bioburden

Unlike single-use consumables, reusable garments and goggles:

1. Are worn by operators with different hygienic habits
2. Undergo multiple wash and reuse cycles
3. Experience variable handling, packaging and transport conditions

Consequently, the pre-sterilization bioburden may vary between batches and within the same load. Since ISO 11137 relies on bioburden information to support dose establishment, substantiation, validation and routine control, limited bioburden characterization or control may weaken the justification for the sterilization process validation.

3.2. Process Variability

Reusable garment workflows include:

1. Collection of used garments
2. Sorting and segregation
3. Washing, rinsing and drying
4. Visual inspection and repair
5. Packaging and sterilization

Each step above introduces opportunities for contamination or variability. To maintain validated sterility, each of these steps must be controlled, monitored and documented effectively, turning the laundry operation into a GMP manufacturing process.

3.3. Material Compatibility

Repeated sterilization cycles can degrade fabrics and plastics:

1. Steam sterilization has the potential to cause shrinkage or a reduction in strength of polyester or Nomex fibers
2. Gamma radiation has the potential to cause embrittlement in elastomer materials
3. Ethylene oxide (EO) residues can remain trapped in multilayer materials

This degradation affects the validation process by altering material porosity and barrier integrity as time progresses. Maintaining consistency, which is required for validation, may become challenging.

4. Regulatory Requirements, Interpretation and Inspector Expectations

While Annex 1 does not explicitly define “validated” in this context, the use of “sterile” is generally understood to require sterility assurance supported by an appropriately validated sterilization process.

1. The Contamination Control Strategy (CCS) must describe how sterility of garments and eyewear is assured
2. If garments are single-use sterile, evidence of supplier qualification and batch sterility certificates suffice
3. If garments are washable and reused, the manufacturer must provide validation data for the laundering and sterilization processes including:
   • Bioburden characterization
   • Sterilization validation per ISO 11137 or ISO 17665
   • Routine monitoring results
   • Material life-cycle studies

In practice, some in-house or external contract laundries may not have the infrastructure, controls, or the supporting data needed to demonstrate full alignment with applicable sterilization validation standards. Where this evidence is limited, single-use sterile consumables may be considered as part of a risk-based contamination control strategy for Grade A and B areas.

5. The Meaning of “Validated Sterile”

5.1. Scientific Definition

“Validated sterile” means that a sterilization process has been:

1. Developed with defined parameters and documented rationale
2. Validated using data demonstrating consistent achievement of an SAL of ≤10-⁶ under worst-case bioburden conditions
3. Controlled through ongoing monitoring, calibration and periodic re-qualification

This aligns with ISO 11137, ISO 17665, and the U.S. FDA’s sterilization guidance for medical devices.

5.2. Why It Matters

Without validation, “sterile” becomes a matter of belief rather than data. In cleanroom clothing, this could lead to uncontrolled microbial or particulate contamination risk, particularly in Grade A/B areas where personnel are often the dominant contamination source. The strengthened language in Annex 1 aims to remove ambiguity and ensure scientific assurance, not assumption.

6. Risk and Operational Impact

6.1. For Manufacturers

Manufacturers operating sterile facilities face three choices:

1. Adopt single-use sterile garments and goggles, simplifying compliance
2. Engage specialized third-party reprocessors capable of validated laundering and sterilization
3. Develop in-house reprocessing validation, requiring investment in infrastructure, documentation and monitoring

Each route carries implications for cost, sustainability and logistics. However, from a regulatory risk perspective, options 1 and 2 often offer the most defensible pathways.

6.2. For Suppliers and Service Providers

Suppliers of reusable clothing and goggles may need to operate beyond a conventional laundry-service model and demonstrate validated processing capability. This involves:

1. Implementing ISO 13485-like quality management systems
2. Conducting routine bioburden monitoring and trend analysis
3. Maintaining validated sterilization equipment and cycle documentation
4. Demonstrating product integrity after multiple sterilization cycles

Such providers can then legitimately claim their garments and eyewear are “validated sterile”.

7. Recommended Approach

7.1. When to Use Single-Use Sterile Products

Single-use sterile garments and goggles are the simplest path to Annex 1 compliance, particularly in:

1. Grade A/B environments
2. High-throughput aseptic processing
3. Facilities preparing for new inspections or regulatory licensing

Advantages include:

1. Supplier-provided validated sterilization certificates
2. No bioburden testing burden on the manufacturer
3. Reduced cross-contamination risk
4. Simplified traceability and CCS documentation

7.2. When to Use Washable Reusables

If reusable clothing is preferred for sustainability or cost reasons:

1. Qualify the service provider as a GMP-like supplier
2. Require full process validation data, including:
   • Bioburden studies pre- and post-wash
   • Sterilization cycle validation (ISO 11137/17665)
   • Product life-cycle studies confirming performance after repeated cycles
3. Audit routinely, verifying continued adherence to validation parameters
4. Maintain traceability via barcoding or RFID tagging for each garment
5. Ensure the garment cleaning detergents are of appropriate grades from reputed suppliers

Only through such rigor can a reusable system be deemed “validated sterile”.

7.3. Documentation and Risk Justification

1. Where technical limitations prevent full validation (e.g., unknown bioburden), manufacturers may include a risk-based justification in their CCS.
2. Demonstrating environmental monitoring data supporting low contamination risk
3. Showing that isolators or RABS minimize operator- product contact
4. Documenting enhanced gowning and handling controls

However, such justifications should be viewed as temporary mitigation, not a long-term substitution for validation.

8. Implementing a Compliance Strategy

A practical implementation roadmap may include:

1. Gap Assessment: Comparing current gowning and eyewear programs against Annex 1 expectationsSupplier Engagement: Obtain validation documentation from garment and goggle suppliers
2. Risk Evaluation (Quality Risk Management): To quantify contamination risk associated with non- validated reusable systems
3. CCS (Contamination Control Strategy) Update: Reflect the chosen strategy, justification, and monitoring program in the contamination control strategy
4. Training and SOPs: Update gowning procedures, donning/doffing practices and handling SOPs to ensure aseptic integrity
5. Continuous Verification: Monitor environmental data, audit suppliers and trend sterilization outcomes This systematic approach integrates both compliance and quality culture, ensuring readiness for inspection and alignment with Annex 1 principles.

9. The Business Case for Compliance

From a commercial standpoint, the shift toward validated sterile consumables reflects not only regulatory evolution but also market maturity:

1. Pharmaceutical and biotech firms increasingly seek standardized, auditable contamination control systems
2. Hospitals, diagnostic labs, and healthcare institutions are adopting similar expectations
3. Reputed garment manufacturers offering traceable, validated sterile consumables are gaining competitive advantage

By articulating the difference between “sterile” and “validated sterile”, garment manufacturers/suppliers position themselves as partners in compliance, not merely product providers.

10. Conclusion

The revised Annex 1 represents a paradigm shift in how sterility assurance is interpreted and applied. The requirement for sterile clothing and eyewear in Grade A and B areas translates directly into a requirement for validated sterile products.

For single-use consumables, compliance is simple: the validation burden lies with the manufacturer. For reusable garments and goggles, achieving validated sterility is technically feasible but operationally demanding.

Unless a reprocessing facility operates under a documented, validated and routinely controlled sterilization program, it cannot claim to supply “validated sterile” items. Regulators will continue to expect scientific assurance, not assumptions or beliefs.

Organizations must align their contamination control strategies with validated sterility principles either by transitioning to single-use sterile consumables or by demanding validated reprocessing from suppliers.

The industry’s direction is clear: “sterile” must mean “validated sterile”. Anything less undermines the integrity of aseptic manufacturing and, ultimately, patient safety.

References

1. European Commission. EudraLex Volume 4, Annex 1 – Manufacture of Sterile Medicinal Products. European Commission, 2022.
2. PIC/S. PIC/S Annex 1 – Manufacture of Sterile Medicinal Products (PE 009-16, Annex 1). Pharmaceutical Inspection Co-operation Scheme, 2023.
3. ISO 11137-1:2006. Sterilization of Health Care Products – Radiation – Requirements for Development, Validation and Routine Control of a Sterilization Process for Medical Devices.
4. ISO 17665-1:2006. Sterilization of Health Care Products – Moist Heat – Requirements for Development, Validation and Routine Control of a Sterilization Process for Medical Devices.
5. Parenteral Drug Association (PDA). Technical Report 70: Fundamentals of Cleaning and Disinfection Programs for Aseptic Manufacturing Facilities. PDA, 2020.
6. PDA Europe Conference Proceedings. Annex 1 Implementation and Industry Lessons Learned, 2023.
7. U.S. FDA’s sterilization guidance for medical devices.
8. USFDA Inspection guide – Sterilization Process Control