How to Add VHP Capability: A Practical Guide for Existing Sterilization Facilities

The decision to add VHP sterilization capability has been made. The strategic case is clear — product categories that cannot be optimally served by EtO are growing, and the facilities positioned to capture that revenue are the ones with validated VHP capability already running. What comes next is the operational question: what does it actually take to stand up VHP alongside an existing EtO operation?

The answer is more straightforward than many facility operators expect — not because VHP validation is simple, but because organizations that already operate validated EtO sterilization have most of the infrastructure, expertise, and quality systems the transition requires. The learning curve is real. The timeline is defined. The pathway is established.

This is that pathway.

Step One: Facility and Infrastructure Assessment

VHP sterilization does not require the emissions control infrastructure that EtO demands. There are no scrubbers, no catalytic oxidizers, no dedicated exhaust stacks, no community air monitoring obligations. Vaporized hydrogen peroxide decomposes to water and oxygen — the post-sterilization aeration phase exhausts a non-toxic byproduct, and the environmental compliance footprint is negligible by comparison.

What VHP does require is defined, and the requirements are modest relative to EtO infrastructure:

**Space and layout.** A VHP sterilization system can be commissioned within a fraction of the footprint of an EtO chamber. The equipment is modular — a chamber unit, a generator, and the associated control and aeration components. Most EtO facilities have available floor space that can accommodate a VHP system without displacing existing operations. Load and unload areas should be planned as cleanroom-compatible spaces with logical flow between them. The two processes — EtO and VHP — operate entirely independently with no shared chambers, no cross-contamination risk, and no scheduling interference.

**Utilities.** Compressed air, electrical connections (voltage and amperage requirements vary by system size), and deionized water for hydrogen peroxide generation are the primary utility inputs. An integrated VHP system benefits from HVAC coordination for the secondary distribution of VHP and the aeration phase, though modular chamber systems can also operate independently of facility HVAC, which simplifies commissioning in retrofit scenarios.

**Control systems.** Modern VHP systems integrate with facility building management systems via standard communication protocols (Ethernet IP, BacNet, Profinet). For contract sterilizers operating under 21 CFR Part 820 quality system requirements, the control system must support 21 CFR Part 11-compliant electronic records — audit trails, access controls, and electronic signatures. This is not new territory for facilities already operating validated EtO processes.

The infrastructure assessment typically takes two to four weeks for a facility that has existing drawings, utility documentation, and a designated floor area. The output is a commissioning plan with confirmed utility connections, spatial layout, HVAC integration requirements, and a control system integration specification.

Step Two: Equipment Selection and User Requirements Specification

Not all VHP systems are equivalent, and the selection decision matters for both operational and validation purposes. The relevant parameters for a contract sterilization facility evaluating multi-product capability are programmability, chamber volume, cycle documentation architecture, and regulatory track record.

A programmable system — one that provides independent control over VHP concentration, temperature, humidity, exposure time, and aeration profile — is the functional prerequisite for a multi-product facility. Fixed-cycle systems cannot accommodate the parameter variability across product types that characterizes modern contract sterilization. If the facility intends to sterilize 3D-printed porous implants, bioabsorbable scaffolds, combination products, and cell therapy components through the same system — each against its own validated cycle — independent parametric control is not optional.

The User Requirements Specification (URS) is the document that translates facility needs into equipment selection criteria. A well-constructed URS defines the target zones and load configurations, cycle parameter ranges required for anticipated product types, documentation and data integrity requirements, control system integration specifications, and validation documentation expectations from the equipment supplier. Investing in URS quality before procurement prevents the specification gaps that generate rework during IQ.

ISO 22441:2022 — the international standard for VHP sterilization process development, validation, and routine control, recognized by the FDA in May 2023 — defines the framework against which the entire validation lifecycle will be conducted. Equipment selection decisions should be made with ISO 22441 compliance as a primary requirement, not a post-hoc check.

Step Three: The Validation Pathway

VHP process validation follows the same IQ/OQ/PQ structure that EtO facilities execute routinely. The terminology, documentation requirements, and regulatory expectations are structurally identical. The technical specifics differ — different critical process parameters, different biological indicators, different cycle characterization methods — but the quality system logic is the same.

ISO 22441:2022's validation framework is organized around three lifecycle phases: Process Development, Performance Qualification, and Routine Control. Each phase has defined inputs, outputs, and acceptance criteria.

**Material Compatibility and Process Development** runs in parallel with the early stages of equipment commissioning, not sequentially after it. The objective is to characterize how the specific product materials and packaging configurations respond to VHP exposure — identifying any materials with VHP sensitivity (certain adhesives, some elastomers, specific optical coatings) and establishing the parameter ranges within which the product and its packaging perform acceptably. This work feeds directly into cycle development and sets the envelope within which IQ/OQ/PQ will be executed.

Bioburden characterization — quantifying the microbial population on unsterilized product — is also conducted during this phase. Bioburden data establishes the baseline for sterility assurance level calculations and drives biological indicator selection and challenge level for PQ.

**Installation Qualification (IQ)** verifies that the VHP system is installed in conformance with design specifications: utility connections, instrumentation calibration, chamber integrity, safety systems, control system documentation, and operational procedures. IQ provides the documented foundation that the equipment is correctly and consistently installed — a prerequisite for OQ testing that means anything.

**Operational Qualification (OQ)** demonstrates that the system performs within specified parameters across its intended operating range under worst-case conditions. OQ for VHP focuses on the critical process parameters that ISO 22441 identifies: VHP concentration uniformity throughout the chamber, temperature stability, humidity control, and exposure time. Physical mapping studies — using calibrated sensors distributed throughout the chamber and load — confirm that VHP distribution is uniform and that no cold spots or low-concentration zones exist that would compromise sterilization efficacy at the product's most challenging locations.

**Performance Qualification (PQ)** provides the definitive evidence that the validated cycle consistently achieves SAL 10⁻⁶ under actual production conditions. ISO 22441 mandates the half-cycle method for PQ: three consecutive successful runs at half the designed exposure time, using process challenge devices (PCDs) inoculated with a minimum of 10⁶ *Geobacillus stearothermophilus* spores — the reference biological indicator organism for VHP sterilization. Successful inactivation across all PQ runs, combined with the physical mapping data from OQ, provides the evidence package that the full validated cycle delivers the required sterility assurance level with a documented safety margin.

**Residue Testing** is conducted as part of the PQ phase and is required by ISO 22441 section 5.4.5. A hydrogen peroxide residuals risk assessment establishes safe residual limits specific to the device being sterilized, and analytical testing confirms that residue levels following the validated cycle fall below those limits. For the product categories VHP is best suited for — bioabsorbables, cell therapy components, combination products — residue characterization is not merely a regulatory box to check. It is the technical demonstration that defines the clinical acceptability of the process.

Realistic Timeline

The question most facility operators ask early in the evaluation process is: how long does this actually take? The honest answer depends on product complexity, regulatory submission requirements, and how much of the process development work can be parallelized with equipment commissioning. But a realistic range for a well-managed implementation is:

- Infrastructure assessment and equipment procurement: 2–4 months - Equipment delivery, installation, and IQ: 1–3 months - Material compatibility, process development, and OQ: 2–4 months - PQ (including biological indicator runs, residue testing, and report preparation): 2–3 months - Regulatory submission preparation: 1–2 months concurrent with PQ

**Total: approximately 6–12 months from procurement decision to validated, submission-ready process.**

The lower end of this range applies to facilities with straightforward product profiles, existing sterilization validation expertise, and a single product type to validate first. The upper end reflects multi-product validation scope or combination products requiring more extensive material compatibility characterization. Facilities with experienced validation teams and documented quality systems move faster — their existing infrastructure absorbs the VHP addition more efficiently than a greenfield operation.

One key accelerant: running material compatibility assessment and cycle development in parallel with equipment delivery and IQ rather than sequentially. This approach compresses the overall timeline without compressing the rigor of any individual phase. It requires planning, but it is standard practice for organizations with the project management bandwidth to execute it.

Regulatory Documentation and Submission

The output of a completed IQ/OQ/PQ validation is a documentation package that supports FDA premarket submissions for devices sterilized by the new process. Under FDA's January 2024 Category A designation for VHP, the review burden is the same as for established modalities like EtO and steam — the submission must demonstrate a validated process, not justify the sterilization method itself.

The core submission package includes the process validation report (IQ/OQ/PQ), biological indicator data, material compatibility testing results, bioburden characterization, residue testing and risk assessment, and cycle parameter documentation aligned with ISO 22441. For 510(k) submissions, this package supports the sterility information section directly. For PMA devices or combination products, the validation documentation is integrated into the broader technical file.

Contract sterilizers adding VHP capability also carry CGMP obligations under 21 CFR Part 820 — equipment qualification records, written process specifications, validation documentation, and ongoing process monitoring records. Facilities already operating validated EtO processes have these systems in place. VHP validation documentation fits within the same quality management framework with no new systemic infrastructure required.

Requalification and Routine Control

Validation is not a one-time event. ISO 22441 requires a scheduled requalification program — annual validation reviews at minimum, with full requalification cycles triggered by significant changes to equipment, load configuration, product design, or process parameters. Facilities that treat validation as an ongoing lifecycle program rather than a project milestone maintain the compliance posture that regulatory inspections require.

Routine process monitoring — biological indicator testing on a defined sampling schedule, parametric release where the validated process parameters are documented for each production run, periodic revalidation against the original acceptance criteria — is the operational expression of a validated process. EtO facilities already execute this for their existing processes. The addition of VHP monitoring adds defined work to an existing quality infrastructure, not a new quality system.

The Straightforward Case for Starting Now

The facilities currently adding VHP capability share a common characteristic: they started before they needed to. They are not responding to a customer ultimatum or a regulatory deadline. They are building capability on a deliberate timeline — with the space, the team bandwidth, and the quality system capacity to execute the validation correctly the first time.

The manufacturers entering the next phase of development — 3D-printed implants, bioabsorbable scaffolds, cell therapy delivery systems, combination products — are making sterilization partner decisions now. They are looking for facilities that can demonstrate existing VHP validation, not facilities that will begin the process after the contract is signed.

A 6–12 month validation timeline means that a facility starting today has validated VHP capability by the end of this year or early next. A facility that defers the decision by one year will complete validation one year later — having missed the early partnership decisions with the product categories that are entering the market in the interim.

The operational path is defined. The regulatory framework is established. The infrastructure requirements are modest for any facility already operating a validated sterilization process. The question is when to start, not whether.

PuroGen's implementation support — process development, IQ/OQ/PQ execution guidance, and regulatory documentation preparation — is designed to compress this timeline without compressing the rigor. The validation science is the same regardless of support model. The difference is the depth of experience behind it.

Frequently Asked Questions

**What is the minimum facility footprint required to add a VHP sterilization system?**

VHP systems are modular and available in a range of chamber sizes. A compact single-product validation system can be commissioned in a space as small as a dedicated alcove or repurposed room within an existing facility. Larger multi-product chambers require more floor area but still represent a fraction of the infrastructure footprint that EtO operations require. The facility assessment phase defines the specific space and utility requirements before procurement, eliminating the guesswork from the capital planning process.

**Can VHP and EtO processes share cleanroom space or personnel?**

Yes — the processes are operationally independent and can share general facility infrastructure, personnel, and quality systems. There is no cross-contamination risk between VHP and EtO chambers, and the two processes run on independent schedules. Personnel trained in sterilization validation and process operations can be cross-trained on VHP with targeted qualification work. The quality management system that governs EtO validation documentation governs VHP documentation under the same structure.

**How does ISO 22441 differ from ISO 11135 for an EtO facility's validation team?**

ISO 22441 for VHP is structurally analogous to ISO 11135 for EtO — both define the requirements for process development, validation, and routine control within the same IQ/OQ/PQ lifecycle framework. The critical process parameters differ (VHP concentration, humidity, temperature, and exposure time vs. EtO concentration, temperature, humidity, and time), and the biological indicator organism is *Geobacillus stearothermophilus* rather than the *Bacillus atrophaeus* used for EtO. Teams experienced with ISO 11135 validation will find ISO 22441 immediately navigable — it is the same validation logic applied to a different sterilization chemistry.

**Does adding VHP require a new FDA registration or facility inspection?**

Contract sterilizers adding a new sterilization modality do not automatically require a new FDA registration, but the facility's existing device establishment registration should be reviewed to confirm the scope covers the new process. Adding a validated VHP sterilization service represents a manufacturing change that may require notification to device manufacturers whose products will be processed — those manufacturers determine whether the change triggers a regulatory submission (e.g., a 510(k) supplement) for their specific devices. The VHP validation documentation package supports any such submissions.

**What does PuroGen's implementation support actually cover?**

PuroGen's implementation model spans the full validation lifecycle: process development support (cycle parameter development, material compatibility assessment planning, bioburden characterization guidance), IQ/OQ/PQ protocol development and execution guidance, biological indicator program design, residue testing oversight, and regulatory documentation preparation. The appropriate model — direct system deployment, private label integration, or strategic collaboration — depends on facility scale and commercial objectives. Contact PuroGen to discuss the right pathway for your operation.