EO Sterilizer For Catheters: How Riches Designs EO Sterilization Solutions For Catheter Manufacturers

Sep 14, 2026

Catheters are classic examples of complex medical devices. Unlike standard flat medical consumables, catheters typically feature long, narrow tubing, internal lumens, combinations of various materials, and complex connection structures. Therefore, when purchasing an EO sterilizer, one cannot simply compare chamber volume and price; it is crucial to determine whether the equipment allows EO gas to fully penetrate the catheter's interior and effectively reduce EO/ECH residuals after sterilization.

As a manufacturer of EO sterilization equipment, Riches aligns equipment and processes based on catheter structure, packaging methods, production capacity, and sterilization protocols.

We first need to understand the materials and components used in the catheter-such as PVC, PU, silicone, PE, and PTFE, as well as connectors, valves, adhesives, and coatings.

Different materials react differently to temperature, humidity, EO exposure, and aeration. Therefore, before designing the EO sterilization cycle, we assess the material's suitability for EO sterilization and monitor for potential issues such as deformation, embrittlement, performance changes, or packaging incompatibility after the process.

Purchasers can provide the equipment manufacturer with the catheter's Bill of Materials (BOM), material composition, dimensions, and details on critical components; this data directly influences the subsequent process design.

The internal lumen of the catheter is one of the most critical factors in EO sterilization design.

For long, narrow catheters, EO gas must not only contact the product's outer surface but also penetrate the internal lumen. Factors such as inner diameter, length, the number of open ends, blind-end structures, and multi-lumen configurations all affect EO penetration.

When designing the solution, Riches analyzes gas entry and exit paths based on the catheter's length, inner diameter, outer diameter, lumen structure, and connector design, while focusing on the hardest-to-sterilize internal areas during the validation phase.

This means equipment design cannot focus solely on "batch loading capacity"; it must also ensure that EO gas can reach the most difficult-to-treat locations.

Catheters typically require individual packaging, tray packaging, or bagging before entering the EO sterilizer. Packaging materials and sealing methods affect EO penetration, air displacement, and subsequent aeration.

We design loading configurations based on packaging dimensions, materials, batch quantities, and sealing methods to prevent excessive stacking that could restrict gas circulation.

For catheter products, packaging design, product orientation, and the sterilization process form an integrated system; they cannot be considered in isolation.

The chamber size of an EO sterilizer should not be selected based solely on the equipment's external dimensions.

Riches typically determines the effective working volume based on the following data:

Catheter Size → Packaging Size → Batch Quantity → Loading Configuration → Required Working Volume

For instance, even with catheter products, the actual working volume required may vary depending on differences in length, packaging dimensions, and batch quantities.

Therefore, we focus on effective loading space and actual production capacity rather than simply offering a sterilizer with standard specifications.

Equipment capacity must ultimately align with the production plan.

Before procurement, we carefully assess the client's daily production, batch quantity, working hours, and target throughput to calculate the required loading capacity per batch and the number of units needed.

We also determine the loading method-such as trays, carts, or other systems-and whether specific spacing between products is required.

Higher loading capacity is not always better; a balance must be struck between production capacity, gas circulation, and sterilization uniformity.

A typical EO sterilization cycle includes:

Preconditioning → Vacuum → Humidification → EO Injection → Exposure → Evacuation → Aeration

Each stage serves a specific purpose. Preconditioning stabilizes the product state; vacuum and humidification create conditions conducive to EO penetration; EO injection and exposure complete the sterilization process; evacuation removes EO from the chamber; and aeration further reduces EO/ECH residuals in the product.

For catheters, we do not simply replicate standard cycles used for other products; instead, we develop and validate the process based on the product's structure, packaging, and actual loading conditions.

Key parameters for EO sterilization include temperature, relative humidity, vacuum/pressure, EO concentration, exposure time, and aeration conditions. Riches determines process parameters based on the client's product and load configuration, while also recording and tracking critical process data.

For catheters, it is insufficient to merely verify that parameters inside the chamber meet setpoints; validation is required to ensure these parameters effectively treat the "worst-case location" within the product itself.

Sterilization completion does not mean the product is ready for immediate release.

Catheter materials, product structure, and packaging methods all influence the rate at which EO and ECH residuals dissipate; components such as long, narrow lumens or materials with high adsorption characteristics may require more extensive aeration.

Riches incorporates aeration into the overall solution design and manages residual control and validation in accordance with applicable regulations and product requirements. Relevant residual limits and testing requirements are assessed against standards such as ISO 10993-7.

For medical devices, equipment procurement is merely the first step; the entire sterilization process requires validation.

Riches provides engineering support covering IQ, OQ, PQ, BIs, PCDs, cycle records, and routine process monitoring.

During validation, we focus on the catheter's worst-case load, the hardest-to-sterilize locations, and sterilization effectiveness within internal lumens to establish a repeatable and traceable EO sterilization process.

As EO is a hazardous sterilization gas, equipment design must extend beyond the sterilization chamber to address EO exhaust, aeration exhaust, leakage monitoring, alarms, interlocks, and ventilation.

Riches plans exhaust treatment and safety systems holistically-considering equipment operation, facility conditions, and local emission standards-to mitigate operational risks associated with EO leakage and emissions.

Riches offers more than just an EO sterilization chamber; we design comprehensive solutions tailored to the client's catheter materials, product dimensions, internal lumens, packaging methods, production capacity, and facility conditions.

From chamber sizing and loading configurations to EO cycles, aeration, exhaust treatment, and validation, we aim to resolve critical process issues prior to equipment manufacturing.

For catheter manufacturers, the key to selecting an EO sterilizer lies not in the size of the chamber, but in ensuring the equipment aligns with their specific product structures and production workflows. If you provide Riches with details regarding catheter specifications, materials, packaging methods, batch sizes, and daily production capacity, we can further evaluate factors such as chamber size, loading configuration, EO sterilization cycles, aeration, and exhaust treatment to develop a comprehensive engineering solution for the EO sterilization of your catheters.

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