The problem with the Precautionary Principal (that you seem to describe) is that it doesn't account for opportunity cost. New compounds are developed for a reas

The problem with the Precautionary Principal (that you seem to describe) is that it doesn't account for opportunity cost. New compounds are developed for a reason and to contribute some value to society. That could be a very small convenience optimization, or could be for a life-saving purpose. While we're waiting for some compound to be deemed 'safe' for some particular use, society is missing out on the benefits of that use. The COVID vaccine is a very timely example of this. It/they haven't gone through nearly the amount of testing and trials that are normally required. But we're going ahead with it anyway, since waiting would cost more lives. This is a judgement call that some set of fallible humans has made. Easy in this huge, public, major case. But for the thousands of compounds developed yearly, who decides this, and at what cost to society in lives, quality of life and resources? And this doesn't count the resources that society has to spend to make the determination of safety, which have their own opportunity cost as well.