Loading Principles of Hydrogen Peroxide Sterilization Transfer Chamber-VHP Sterilization Transfer Window-TKSAGE (Shenzhen) Technology Group Co., Ltd.

In aseptic production, biosafety laboratories and high-end medical environments, hydrogen peroxide sterilization transfer chamber (also known as VHP transfer chamber) is a key barrier to ensure the safe transfer of items between clean areas. Its core value lies in the use of vaporized hydrogen peroxide's powerful broad-spectrum sterilization ability. However, many operators and designers often underestimate a key fact: the sterilization effect is not simply determined by the performance of the transfer chamber, and the loading method of the items has a decisive influence on its effectiveness, uniformity and process reliability. The penetration, contact and concentration maintenance of sterilant vapor are all subject to the invisible constraints of the loading state.

Mastering and strictly implementing scientific loading principles is the cornerstone of ensuring the best performance of hydrogen peroxide sterilization transfer chamber:

Orderly placement to ensure unimpeded airflow:

Core goal: Ensure that vaporized hydrogen peroxide vapor can freely and evenly diffuse into every corner of the chamber and fully contact with all surfaces of items.

Key points for practice:

Avoid close stacking: There must be enough space between items. Imagine steam as water flow, which needs channels to spread. Close stacking will form an impenetrable "dead zone" where steam cannot enter, and sterilization will naturally fail.

Direction optimization: The most complex surface of the item, the inner cavity opening, or the most potentially contaminated surface should face the steam release port or the main airflow direction. For example, the open container mouth should face upward or toward the airflow, and the catheter and instrument joints should be spread out to avoid closing.

Avoid blocking: Never place items directly in front of the steam nozzle to block its diffusion path. Pay special attention to the placement of large items to prevent the formation of airflow blind spots behind them.

Use racks/trays: Use matching racks or trays in a standardized manner to place items in layers and separately. Single-layer placement is the most ideal choice to maximize the steam contact area.

Strictly control loading density and volume:

Core challenges: Hydrogen peroxide vapor will be absorbed and consumed by the surface of the item (especially porous materials) during the sterilization process, and too high a loading amount will significantly hinder the diffusion and circulation of steam.

Practice points:

Comply with equipment specifications: Strictly follow the manufacturer's manual on the maximum load volume or weight of the clear limit (for example, it is usually recommended that the full load volume does not exceed 30%-50% of the effective volume of the chamber, the specific value varies greatly depending on the equipment model and the material of the items). Do not overload!

Reserve sufficient space: Ensure that after loading, there are clearly visible gaps on the top, bottom and sides of the chamber to create the necessary conditions for steam flow, mixing and backflow.

Prioritize similar/similar items: Try to choose items of similar material, size and shape for a single load, which is conducive to parameter setting and ensuring sterilization uniformity. Avoid burying a small number of small items under large items.

Avoid contact and overlap of items:

Core risk: Close contact between the surfaces of items will form a physical barrier that prevents steam from reaching the contact interface. Overlapping will inevitably lead to insufficient surface exposure of the lower or inner layer of items.

Practice points:

Independent placement: Ensure that each item is separated from other items, and there is a gap in between for steam to flow.

Avoid stacking: It is strictly forbidden to stack items directly (such as stacking multiple trays or pressing multiple packaging bags together). If multi-layer shelves must be used, ensure that there is a gap of sufficient height between the layers to support steam penetration.

Bag handling: Sterilization bags should be laid flat on the shelves in a single layer to avoid curling, folding or squeezing each other. There should also be gaps between bags.

Material compatibility and characteristic recognition:

Core insight: Different materials have significant differences in absorption and adsorption characteristics of hydrogen peroxide vapor, which directly affects the effective concentration and action time of the sterilant in the local area.

Practice points:

Strictly check compatibility: All items placed in the transfer chamber must be verified to be fully compatible with the hydrogen peroxide vaporization sterilization process to avoid material corrosion, degradation or toxic residues.

Distinguish between high and low adsorption:

Highly adsorbent materials (such as paper, cotton cloth, cellulose products, etc.): They will absorb and consume a large amount of hydrogen peroxide vapor, which may cause a sudden drop in concentration in the chamber and make the entire sterilization cycle ineffective. Requires extremely careful evaluation, usually requiring lower loads, longer sterilization times or dedicated cycles. Try to avoid mixing large quantities of such items with other low-absorbent items.

Low-absorbent materials (such as stainless steel, glass, and certain plastics such as polypropylene/polycarbonate): consume less steam and are relatively easy to sterilize. However, all loading principles must still be followed.

Consider packaging: If the item is packaged (such as sterilization bags, breathing bags), the packaging material must also be compatible and cannot hinder steam penetration. Make sure the packaging is completely open or use verified breathable packaging materials.

Standardized loading and strict records:

Core guarantee: The basis for traceability, consistency and continuous improvement.

Practice points:

Standard operating procedures: Establish detailed and clear written loading standard operating procedures to clarify the recommended placement of various items, maximum loading limits, precautions, etc., and train and evaluate all operators.

Loading map: Create and verify "loading maps" for frequently handled and typical loading configurations. The diagram clearly indicates the specific position and direction of each item in the chamber, ensuring that each loading according to this diagram can achieve a consistent and effective sterilization effect. This is crucial for validation and daily operations.

Detailed records: For each sterilization operation, the actual list of loaded items, quantity, and placement diagram (or the standard diagram number used) must be recorded. This is an indispensable key evidence for problem tracing and process optimization.

Regular review and verification: Regularly review the loading operation, and regularly verify the actual sterilization effect under a specific loading mode through biological indicator challenge testing (placing BI in the most difficult to sterilize position). Major changes in loading methods must be revalidated.

Ignoring these seemingly trivial loading principles is equivalent to actively creating loopholes in the carefully designed sterilization barrier. It may directly lead to:

Sterilization failure, causing product or sample contamination, bringing huge quality risks and safety accidents.

Uneven sterilization effect, some areas are qualified for sterilization while others fail.

Being forced to extend the sterilization time or increase the hydrogen peroxide concentration not only increases costs, but may also accelerate the aging of equipment components or damage items.

Frequent sterilization validation failures, consuming additional time and resources for deviation investigations.