study design

Experiment – mixed model. Between and within subject randomization: At the beginning of the survey every participant gets general information about the study: Purpose of the study, Withdraw-information, Data protection, Contact details). This part ends with the given consent and a personal code generated by the participants. Additionally, every participant gets information about the principle of regulation of chemicals in the EU. This serves as an informed assessment of the future regulation of products, which we request from the participants during the study. In a second step, the trust of the test subjects in regulations by the government and in the labelling of product content is recorded. This takes place before the actual experiment to avoid confounding with the increase in knowledge over the course of the study (Siegrist & Cvetkovich, 2000). After this general introduction the participants are divided into two groups based on the object they are working with over the whole experiment (bottle of household cleaner / tube of toothpaste). Nine different versions of the object (toothpaste/ household cleaner) with different chemical properties serve as the independent variable and as the dependent variable, the risk perception is approximated by the subjects' assessment on 4 different bipolar 7-point Likert scales. The experimental phase is designed semi-randomly in both groups. Each implementation starts with the base-line object, where the object is presented without any information of its chemical properties. Then eight different looking objects with manipulated chemical properties (persistent chemicals (P), mobile chemicals (M), toxic chemicals (T), PM, PT, MT, PMT, PMT-free) are shown in a random order. After each object, the participants are asked to give their assessment on four different bipolar 7-point Likert scales. An affective scale, based on the holistic affect scale (Slovic & Peters, 2006; Van Der Linden, 2015), on which the participants should rate whether they see the product as something very positive – very negative. A usefulness scale, on which the participants should rate, whether they see the product as not useful at all – very useful. A Concern scale, on which the participants should rate how concerned they personally are with using the product in their everyday life: not concerned at all – very concerned. And a regulation scale, on which they should rate, whether they think it is important to regulate the use of this product: completely disagree – completely agree. As a validation of the mediator effect of the object kind the participants are working with, a question, about the amount of body contact while using the specific object, follows. (7-point Likert scale: No body contact at all – A lot of body contact). Then the participants are asked to assess with a slider (0%-100%) the additional money they are willing to spend on a PMT-free Version of the object. The last block is a concentration check in the form of a query of the anagram P-M-T, a subjective prior knowledge scale and a query of socio-demographic data (age, gender, education, place of residence, income, political orientation). The survey will end with the possibility to give feedback and comments on the study.