I recently reviewed ISO 19227 and I'm a bit surprised at the extent of testing. It would appear to require testing with statistically valid sample sizes for: visual, LAL, TOC, THC, Inorganic contaminants, and cytotoxicity. I believe we could waive bioburden and particulate, since we don't perform the final sterile packaging of the device. When I consider 2-runs for an OQ and 3 for a PQ, times 6-tests, times a valid sample size, then the numbers rapidly grow. Does anyone have any experience with the cost to validate to this standard? It is probably the right thing to do, but the cost would appear to be outside what most manufacturers are likely to absorb. I suspect compliance to this standard is very low. Do any of you have experience justifying a very low sample size? In my experience, many manufacturers use a single unit for many biocompatibility tests. I'm not suggesting that's right, but I'm not aware of the ISO 10993 series providing any guidance on sample size.