Actually, no, this doesn't make sense to me. If a manufacturer is in charge of safety-testing its own product, there is an obvious conflict of interest and incentive to interpret the test result as favorable for the product as possible. (Or to tailor the product to the test)
To put it bluntly, you wouldn't put the wolf in charge of safety-testing the chicken pen either.
So especially for safety tests a publicly funded, independent institution would make sense to me. (Of course, keeping that institution independent is another problem)