By law, the US government must publicly display the quantities of harmful chemicals in cigarettes by brand, but doing so could mislead people to incorrectly think that some cigarettes are safer than others. We evaluated formats for presenting chemical quantities side-by-side to see if any were misleading. We recruited US convenience (n = 604) and probability (n = 1440) samples. We randomized participants to 1 of 5 formats: checklist, point estimates, ranges, a visual risk indicator, or no-quantity control. Participants were far more likely to incorrectly endorse one cigarette brand as riskier than the other in the checklist (65% made error), point estimate (67–70%), range (64–67%), or risk indicator (68–75%) conditions as compared to the no-quantity control (1%, all p <.001). Among smokers, erroneous risk perceptions mediated the impact of quantity format on interest in switching brands. People viewing chemical quantities for cigarette brands side-by-side misperceived differences in risk, suggesting limited public health value of this information
