Currently, there is no mandatory labeling for products containing synthetic nanoparticles. The public as well as other stakeholders have positive views about mandatory labeling. However, little is known how such a label influences the risk and benefit perception of a product. Consumers may infer that a label is a signal that there are risks associated with this technology. Data were collected in a survey experiment (N= 1,382). Participants were randomly assigned to one of six conditions. The control group received a picture of a sunscreen container without a label. One experimental group received a picture of a sunscreen container with a label. The other groups received, in addition to the sunscreen container with a label, some risk or benefit information. Results suggest that labeling of products may reduce consumers’ benefit perception and increase risk perception. Labeling nanotechnology consumer products may change the public perception of the products. Respondents may have relied on the affect heuristic for assessing the risks and benefits of the sunscreen.