In the past, scientists were usually considered trustworthy by default. More recently, a shift to a sort of ‘wariness by default’ can be observed. Scientific knowledge about the safety of vaccines or 5G radio frequency electromagnetic fields is openly questioned. Mutually exclusive strings of scientific evidence allow stakeholders and policy makers to substantiate similarly contrasting policy preferences. Scientific advisory institutes, such as the Dutch National Institute for Public Health and the Environment (RIVM), are seeking ways to respond to these trends.

In this thesis, the issue of endocrine disrupting substances was selected to study the diverse argumentation underlying international differences in stakeholders’ regulatory preferences, in the context of ongoing scientific controversy. We studied eight complementary conceptual frameworks from different disciplines, providing different views on the origin of the observed international differences. We also performed two argumentation analyses, using Pragma-Dialectical Argumentation Theory. We analyzed the polarized scientific debate on endocrine disrupting substances, and stakeholder responses on a public EU consultation concerning endocrine disrupting substances regulation.

We conclude that scientific experts should be transparent about personal and professional values present in their research, particularly in advisory work. Secondly, policy makers should be aware that disputes over broader norms and values should be settled in the political rather than scientific arena, even though disputes appear to be purely technical on face value. Inclusive risk governance approaches are more suitable to deal with value-laden scientific issues, rather than unconditionally following the credo ‘more research is needed’.