How to Choose a Contract Sterilization Vendor

When outsourcing sterilization of medical devices, OEMs should consider their current needs as well as their plans for future growth.

July 30, 2014

4 Min Read
How to Choose a Contract Sterilization Vendor

By Martell Winters and Paul L. Littley

In the world of contract sterilization, selecting the most appropriate service provider can be a daunting task. Even for the seasoned expert, determining the right fit for the needs of your medical device business is an intimidating process. With typical validation periods ranging from two to four months, it would be financially detrimental to complete a validation only to find the new relationship isn’t the right fit after the first month of processing.

When choosing a contract sterilization vendor, there are myriad considerations and questions that must be asked to ensure the final selection will not only meet your company’s immediate needs, but also provide scalability for future growth. Although the following priorities are, in our experience, the logical progression for selection, not all medtech manufacturers may share the same priorities for their selection. Nevertheless, the following considerations should provide the necessary guidance for selecting a contract sterilization vendor. (Additional information and guidance for ethylene oxide contract sterilization can be found in AAMI TIR14, “Contract Sterilization Using Ethylene Oxide.”)


One of the first considerations for OEMs should be the proximity of the contract sterilization facility to the manufacturing site. Transport costs of processing multiple sterilization batches per week can add up quickly. When budgeting, remember to consider return shipment charges.

Turnaround Time

Arguably, the main priority for your outsourcing selection is the ability to get a sellable product to market quickly. When analyzing turnaround time, chamber or carrier size, facility capacity, and the sterilization process, logistics all become a careful balancing act. For ethylene oxide sterilization, does a traditional three-phase process (separate phases of preconditioning, sterilization chamber, and aeration) meet the business need with a turnaround time of approximately five days, or is an “all-in-one” process (typically completed in 24 hours) more appropriate? For radiation, does validation of a typical dose, such as 25 kGy, facilitate a faster turnaround time at the selected location? All of these factors should be considered when assessing contract sterilization partners.


In many organizations, cost will be the primary consideration when selecting a contract sterilization provider. Many companies may not have the operating margins or be in a financial position to be able to afford the price of the “perfect” contract sterilization facility. It’s important to strike a balance between the business needs and the “ideal scenario.”

Chamber Equivalency

When it comes to ethylene oxide sterilization—a common technique used on medical devices—chamber equivalency is important not only for overflow purposes (capacity restraints) but additionally as a contingency strategy. Established chamber equivalency reduces the validation scope of an additional chamber and provides back-up in the event of unscheduled maintenance and capacity restraints. Maintaining multiple validated chambers provides a critical insurance policy to ensure an uninterrupted sterilization process.

Process Controls

Several high-level aspects of quality control stand out when selecting a sterilization vendor. High on the list of process controls is product segregation. Segregation of processed and unprocessed product is paramount, as it is impossible to identify if a product has been sterilized by visual inspection. The vendor should be able to physically confirm that its process or product flow provides clear separation of processed and unprocessed product and that the two never cross paths.

Other key quality aspects to consider are the cleanliness of the facility and its pest control practices. Even a single dead (sterilized) bug provided with your medical device reflects poorly on the quality control of your manufacturing process. Facility pest control should not be ignored or overlooked. Effective housekeeping is a sure sign of the quality of a contract sterilization facility.

It is also important to remember that contract sterilization facilities do not ensure the sterility of your product, only that the validated cycle was run to your specification and that any nonconformances were identified. The ultimate responsibility of product sterility rests in your hands.

Supplier Approval

The final consideration for selection of the appropriate vendor should entail a formal review of the vendor’s regulatory compliance history and conformance to good manufacturing practices. The manufacturer should follow standard protocol for supplier approval including a quality system audit of the candidate vendor. It should also be clear that the vendor fully understands and follows the appropriate AAMI and ISO sterilization standards.


Medical device companies continually seek ways to reduce costs and increase efficiency in the manufacture of their products. While the outsourcing of sterilization provides convenience, efficiency, and initial cost savings, it is crucial that companies looking to outsource be well versed in the criteria that should be considered during the selection process. Prioritized business needs and careful, informed selection will provide years of seamless product sterilization for the manufacturer.

Martell Winters is a senior scientist at Nelson Laboratories. Reach him at [email protected].

Paul L. Littley is a consulting manager at Nelson Laboratories. E-mail him at [email protected]

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