VHP Material Compatibility: What Can Go Into a Hydrogen Peroxide Cycle
Two different things can go wrong when a material meets hydrogen peroxide vapour: the material can be damaged, or it can quietly absorb the vapour and undermine the cycle. This guide covers both, with a practical material table and how to confirm compatibility for your own load.
- Compatibility has two sides: damage to the material, and the material’s effect on the cycle (absorption, decomposition, off-gassing).
- Cellulose (paper, cardboard, cotton, wood) and liquids are the usual problem loads — remove or replace them.
- 316L stainless steel, glass, PTFE, PVDF, PP and PE are the safe reference materials; elastomers and some plastics need checking.
- Confirm with coupon exposure over a realistic number of cycles, and include absorbent materials in the cycle-development load.
Why compatibility is a two-sided question
Vaporized hydrogen peroxide (VHP) is a strong oxidiser, but it is used at low concentrations — typically a few hundred ppm — and, in a well-run cycle, without condensation. That is why it is regarded as one of the gentler sporicidal processes for rooms, isolators and equipment. “Gentle” does not mean every material is suitable, and the question has two sides that are easy to confuse.
- Does the vapour damage the material? Oxidation, tarnishing, corrosion, embrittlement, cracking or discolouration — usually cumulative over many cycles rather than visible after one.
- Does the material damage the cycle? Some materials absorb hydrogen peroxide or catalytically break it down. The concentration in the space drops, surfaces near the material may not reach the required dose, and whatever was absorbed is released again during aeration, often for hours.
The second effect is the one that surprises people. A room full of cardboard boxes can survive a VHP cycle without any visible change, yet the cycle fails its biological indicators and takes far longer to aerate.
Material guide
The table below is general guidance drawn from common industry experience. Behaviour depends on concentration, exposure time, temperature, the number of cycles and the specific grade or formulation, so treat it as a starting point for your own assessment, not a substitute for testing.
| Material | Typical behaviour with VHP | Practical guidance |
|---|---|---|
| Stainless steel 304 / 316L | Highly resistant; the reference material for VHP-exposed surfaces. | Preferred for chambers, isolators and fixtures. Smooth or electropolished finishes also aerate faster. |
| Glass | Resistant. | Suitable. Make sure surfaces are dry before the cycle. |
| Anodised aluminium | Generally resistant. | Usually acceptable; confirm for bare or machined aluminium exposed to frequent cycles. |
| Copper, brass, bronze | Tarnish over repeated cycles and catalyse H₂O₂ breakdown. | Limit exposed area; plate, coat or cover where practical; test critical parts. |
| Carbon / mild steel | Corrodes when unprotected. | Avoid bare surfaces; use coated or stainless alternatives. |
| PTFE, PVDF, PP, PE (HDPE), PEEK | Good resistance. | Suitable for tubing, seals, trays and wrapping. |
| PVC, polycarbonate, acrylic (PMMA) | Generally usable; some grades can craze or yellow under stress and repeated exposure. | Common in windows and panels; check with the supplier and by coupon testing for high-frequency cycles. |
| Nylon (polyamide), polyurethane | Variable; some grades absorb peroxide or degrade. | Test before use, or replace with a known-resistant polymer. |
| Silicone, EPDM, FKM | Resistant, but silicone in particular absorbs H₂O₂ and releases it slowly. | Good gasket choices. Large silicone areas lengthen aeration — account for it in cycle development. |
| Natural rubber, latex | Degrade. | Avoid. |
| Neoprene and CSM gloves and sleeves | Widely used in VHP isolators; absorb peroxide. | Often the slowest item to aerate in an isolator. Use the glove supplier’s VHP data. |
| Paper, cardboard, cotton, wood | Absorb and decompose vapour (cellulose). | Remove from the space. Use HDPE spunbond or plastic packaging instead of paper. |
| Water and other liquids | Absorb vapour; VHP does not sterilise inside liquids. | Remove or seal. Dry wet surfaces before the cycle. |
| Oils and greases | Can absorb vapour and shield the surface beneath. | Clean off before decontamination; use compatible lubricants. |
| Electronics (enclosed) | Usually tolerate non-condensing VHP cycles well. | Common in rooms and isolators. Exposed connectors and copper tracks can tarnish over time; confirm for critical instruments. |
General guidance only. Grades and formulations differ — confirm by testing under your cycle conditions.
Surfaces the vapour cannot reach
VHP is a surface process. It acts on surfaces it can contact, so compatibility planning also means looking at geometry:
- Occluded surfaces — under labels, inside threads, between stacked items, beneath items resting flat on a bench.
- Closed volumes — sealed bottles, closed drawers and cabinets, capped tubes.
- Mated surfaces — tight-fitting lids, clamped joints, overlapping gaskets.
Open, separate and raise items so vapour can reach every surface that needs treatment. Anything that has to stay closed during the cycle should be decontaminated in another way.
Condensation changes everything
Most compatibility problems are made worse by condensation. When vapour condenses, a liquid film of concentrated hydrogen peroxide forms on surfaces — far more aggressive than the vapour itself, and slower to remove. Cold surfaces, overdosing and poor distribution are the usual causes. A cycle designed to stay below the dew point protects materials as well as making results more reproducible.
How to confirm compatibility for your load
- List the materials. Every surface that will be exposed: structure, finishes, gaskets, gloves, windows, equipment housings, cables, packaging and anything stored in the space.
- Screen against supplier data. Equipment and component manufacturers often hold VHP compatibility data. Ask for it before buying new fittings.
- Coupon testing. Expose representative coupons or spare parts to a number of cycles that represents the intended service life, then inspect appearance, dimensions, weight, mechanical properties or function as relevant.
- Test the effect on the cycle. Include absorbent materials in the cycle-development load, place biological and chemical indicators near them, and measure aeration time with them present.
- Lock it down. Write the allowed and prohibited materials into the loading procedure, so the validated load stays the load that is actually run.
References
ISO 22441:2022 — Low temperature vaporized hydrogen peroxide sterilization
USP <1229.11> Vapor Phase Sterilization
EU GMP Annex 1 (2022), Manufacture of Sterile Medicinal Products
Fenggu equipment for this
VHP pass box
Decontaminates the outer surfaces of components and sealed containers entering Grade A/B areas.
View specifications →FG-VHP-M500Mobile VHP room sterilizer
For rooms up to 300 m³, including rooms with instruments and fixed equipment.
View specifications →FG-VHP-GLRecirculating VHP generator
Closed-loop decontamination of biosafety cabinets, centrifuges and enclosed equipment.
View specifications →Related application guides: VHP pass box material transfer · Isolator and RABS decontamination
Common questions
Can paper and cardboard go through a VHP cycle?
Generally not. Cellulose absorbs and breaks down hydrogen peroxide vapour, which lowers the concentration near the load and releases peroxide again during aeration. Remove paper and cardboard, or replace them with HDPE spunbond or plastic packaging.
Is VHP safe for electronic equipment?
Many enclosed electronic devices tolerate VHP cycles that are run under non-condensing conditions, which is one reason VHP is used in rooms and isolators that contain instruments. Exposed connectors and copper can tarnish over repeated cycles, so confirm compatibility for critical instruments with the manufacturer or by testing.
Why do isolator gloves slow down aeration?
Glove and sleeve materials such as neoprene and CSM absorb hydrogen peroxide during the exposure phase and release it slowly afterwards. In many isolators they are the last surfaces to reach the residual limit, so glove material and area are part of cycle development.
How many cycles should a compatibility test cover?
Enough to represent the intended service life of the material. Estimate how often the space will be decontaminated and for how many years, and design the test exposure around that number.
Does VHP sterilise inside liquids or closed containers?
No. VHP acts on the surfaces it can reach. Liquids and closed containers shield what is inside, and liquids also absorb the vapour, so they should be removed or treated by another method.
Have a specific space or load in mind?
Send the volume, the materials and what you need to prove. An engineer replies with a recommended setup and what validation will involve.