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Posted: November 20, 2017

Cytotoxicity Failure Program

Cytotoxicity Failures

Cytotoxicity testing is designed to demonstrate if there are cytotoxic leachable substances from medical devices or materials. Cytotoxicity testing is the most sensitive biocompatibility test and is used for safety testing of all medical devices with patient contact.  It is also used frequently as a routine screening test for raw materials.

Occasionally, a device or material will exhibit a level of cytotoxic reactivity that is higher than what is allowed by the ANSI/AAMI/ISO 10993-5 standard and will result in a failed test. Although your product may have failed a cytotoxicity test, it doesn’t necessarily mean that your device or material is unsafe for clinical use. It simply means that you are obligated to identify the source of the failure and assess any toxicological risks. There are several possible causes for a failure, and Nelson Labs provides services to help you assess the failure and any toxicological risks.

Cytotoxicity Failure Program

Reconstructed human epidermis (RHE) for in vitro skin irritation and sensitization testing.

In the past, if your product failed cytotoxicity testing, you would need to send new samples for additional testing to determine the cause of the failure. We have recently added a new service to help our customers potentially save time and money when conducting these evaluations. If you request the Nelson Labs Cytotoxicity Failure Program when submitting your samples to the lab, we will store a sample of the extraction fluid from your cytotoxicity test until you receive your test results. In the case of a failing result, we will connect you with one of our subject matter experts who will help you develop a plan for investigation. Because we have retained a sample extract from your original cytotoxicity test, we can quickly test the retained fluid without the need for a new sample. We typically test for metals in these cases, as the presence of metals from the manufacturing process, handling, or colorants is a primary cause for failed cytotoxicity tests.

If the test detects cytotoxic metals in the extract, we will then contact you with details regarding initiating a toxicological risk assessment. Our toxicologists can assess the metals and determine if the concentration would be sufficient to lead to any patient safety issues. This analysis can also be helpful to decide if an investigation regarding the source of the contamination should be conducted.

The cytotoxicity test is a highly sensitive toxicity assay which is designed to determine if there are cytotoxic leachable substances or surface contaminants present in medical devices or raw materials. It is required testing for most medical devices and is used frequently as a routine screening test for raw materials and cleaning validations.

There are several possible causes for a failure, and Nelson Labs provides services to help you assess the failure and any toxicological risks.

If you would like to discuss this program, contact your Account Manager or

About Nelson Laboratories, LLC

Established in 1985, Nelson Laboratories is a leading provider of microbiological testing and consulting services for MedTech companies. We know that every test matters and requires solutions that improve patient outcomes and minimize customer risk. We call it "The Science of Success®." It means working with customers to solve complex problems, providing precise test results, and delivering value through superior testing solutions and service to ensure the safety and efficacy of every product. Nelson Laboratories is a standalone business within Sotera Health LLC, the global leader in outsourced contract sterilization services, gamma technologies, and medical isotopes. Visit for more information.

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