Prof. Hansson is a member of “forskningsberedningen”, the Swedish government’s advisory board of researchers since December 2000. He has been a member of three Boards of Directors appointed by the Swedish Government: the Products Control Board (1976–1982; the predecessor of the National Chemicals Inspectorate), the National Board for Spent Nuclear Fuel (1981–1992) and the Natural Science Foundation (1989–1992). He has also been a full member of two temporary Commissions appointed by Government, both with tasks in environmental policies. In 1999–2000 he was advisor (“expert”) to a temporary Swedish government committee (“kemikaliekommittén”). He is a co-opted member of the board of the MISTRA project New Strategy for the risk management of chemical substances.

Since September 1999 he is the editor of Theoria, the only international, refereed, philosophy journal published in Sweden. Since 2001 he is vice chairperson of Riskkollegiet, a Swedish association for risk research. He was the founding chairperson of the Swedish Skeptics (Vetenskap och folkbildning). He is still a board member and editor of the organisation’s journal Folkvett.