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Biocompatibility after pickling

Hi I work for a company that manufactures medical device, last week we had a problem with parts from our supplier, we use ss304L, and parts turn gold by an error in one of their process. They suggested that if we can't wait they can pickle the parts in a process of pickling and passivation. Our concern now is if these parts after the pickling process will fail the biocompatibility test or this process is safe for medical device. We already send parts to a lab to test them in the cytotoxicity test. Is this enough our all the five test are necessary? Is pickling safe?

Nidal Younis
Quality Engineer - Puerto Rico
2007

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2007

Is the gold color from a heat tint oxide or TiN coating or ? A heat tint oxide formed in a moisture-free furnace atmosphere can yield a passivated surface, as mentioned by Don Mattox in the Passivation FAQ.

Pickling should be followed by nitric acid passivation to improve the biocompatibility of 304L. This passivation will remove surface nickel, a common cause of bioincompatibility.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.