[renewiltord]

I imagine the LD50 of many substances are defacto non-reproducible despite being mechanically replicable. i.e. the world will not permit us to test the LD50 of FOOF so any measure of its danger to human lives is defacto untestable. Yet we have a notion of its truth.

Of course there is an epistemological distinction here between a thing that cannot be reproduced by its nature vs. one that cannot be reproduced by societal norms.