We have one issue where the resin that was supplied by a supplier had some color variation. Since there was no limit samples for the resin, the lot was released by QC. After molding, we saw that the color of the molded samples was way off the "finished product samples".

The customer is requesting us to test the molded samples as per ISO 10993 - 5 for the cytotoxicity testing. I am trying to put up the justification that testing per ISO 10993 - 5 is not required as there is no change in the raw material per se and the chemical properties of the resin are unaffected. We have also written to the supplier and a detailed investigation is underway.

How would you handle this situation ? Is testing per ISO 10993 - 5 required ?

The customer is requesting us to test the molded samples as per ISO 10993 - 5 for the cytotoxicity testing. I am trying to put up the justification that testing per ISO 10993 - 5 is not required as there is no change in the raw material per se and the chemical properties of the resin are unaffected.

If there was no change in the material, why was the color different?

I think the customer's point of view is the product you supplied decreased the value of the parts. You're probably going to end up doing what the customer wants in order to keep the business.


We have also written to the supplier and a detailed investigation is underway.
Good start from a technical point of view, and you may be able to pass on the liability to your resin supplier.

How would you handle this situation ? Is testing per ISO 10993 - 5 required ?It's not an issue of chemistry. It's an issue of customer satisfaction. You're probably going to have no choice but accede to the customer's demands.

Specifications seldom tell the whole story. This is why W.E. Deming hammered so hard on reducing variation.

Cyto is also "just" a screening test, it may be your customer just wants to provide evidence of basic risk management.

We obtained a written statement from the resin supplier that the chemistry of the resin is not compromised. With this letter, luckily the customer agreed not to go in for fresh ISO 10993 - 5 testing.