"Those who emphasize individual or local choice, may view fluoridation as a violation of ethical or legal rules that prohibit medical treatment without medical supervision or informed consent or that prohibit administration of unlicensed medical substances, view it as "mass medication", or may even characterize it as a violation of the Nuremberg Code and the Council of Europe's Biomedical Convention of 1999.Another journal article suggested applying the precautionary principle to this controversy, which calls for public policy to reflect a conservative approach to minimize risk in the setting where harm is possible (but not necessarily confirmed) and where the science is not settled.