Are you stupid or do you not understand statistics? You can mandate a company guarantee their products be 99% free of contamination, or 99.9% free, or even as high 99.99999% free. But you can never guarantee something be 100% free of contamination. There is always risk. The best you can do is mandate a product be within safe limits. In the real world you can get functionally close to 0% or 100% but you can never achieve them.