Transparent decisions are decisions in which the decision maker clearly presents to others the normative and factual premises behind the conclusions and explains the reasoning leading from these premises to the conclusion. Transparency thus involves uncovering, describing, documenting and communicating all the argumentative steps in the line of reasoning. It also involves acknowledging the weighting of any evidence drawn upon in reaching the final decision. It is recommended that each decision should be accompanied by an audit trail describing the premises justifying it. Uncertainties should be presented in connection with each possible adverse effect to indicate alternative scenarios to the most likely risk characterisation together with an evaluation of the reliability of each of the alternative scenarios. It is recommended that times and places for dialogue and participation be established. Transparency in this sense demands new efforts from the authorities and scientific advisors.