Risk science is the study of the effect of exposure to certain substances and activities on public health and safety. The effects produced may be beneficial or harmful, depending on the substance or activity under study and the dose to which one is exposed. As is commonly known, too little water is as harmful as too much water, while a moderate amount is very beneficial. In addition, a deadly substance that only exists on Saturn is of no concern to humans because our exposure to it is zero.
Risk science is, of course, more complex than these two simple examples imply. It must take into account many factors, consider their interactions, and try to uncover the true effect hidden under many layers of complexity. Just like any science, risk science is a systematized study. Yet as long as the best process is carefully and transparently followed, we can trust that objective knowledge will eventually prevail. The danger, as in any science, is when the study is done ad hoc and behind closed doors. The scientific method cannot be jeopardized for the sake of superficially gratifying regulatory policies made contrary to evidence or under unacceptable levels of uncertainty.