Abstract
BACKGROUND: Most people do not apply sunscreen effectively. The Australian and New Zealand standard for sunscreen specifies labels must provide clear and adequate directions for use but does not prescribe specific wording or positioning. Additionally, water-resistant sunscreens must declare the duration of laboratory-tested water resistance, up to 4 h maximum. Formative research found consumers are confused by reapplication directions and water resistance claims. This study aimed to explore whether enhanced sunscreen labelling information can improve sunscreen reapplication. METHODS: Adult sunscreen users (n = 3,363) were randomised to view one of ten mock sunscreen labels in a 2 × 5 online experiment. Labels differed according to front-of-pack (FOP) water resistance claim (standard: tested for 4 h water resistance vs. alternative: water resistant) and reapplication information (none vs. any; with four message variations: simple text, simple icon, extended text, extended icon). We used multivariate logistic regression to examine the effect of FOP labelling on knowledge and intention to reapply sunscreen every 2 h and after swimming, sweating and towel drying (henceforth: activity), considering: (i) water resistance and reapplication information and (ii) reapplication message type. RESULTS: Compared to no information, FOP reapplication information increased knowledge (48% vs. 70%) and intention to reapply within 2 h (41% vs. 54%), but not after activity. Compared to the standard claim, the alternative water resistant claim increased knowledge (60% vs. 72%) and intention to reapply within 2 h (47% vs. 56%), but not after activity. Although there was no clear pattern of effects for reapplication message type, only the extended icon (with directions to reapply every 2 h or after activity) increased knowledge to reapply after activity, irrespective of the water resistance claim (52% standard and 57% alternative). CONCLUSIONS: Under the current standard, sunscreen labels do not provide clear directions for use, which leaves consumers vulnerable to UV damage. Mandating FOP reapplication directions and adopting an alternative 'water resistant' claim could improve consumer understanding of how often to reapply sunscreen. Due to common misperceptions about the limits of water resistance, further user-centred label design and public education is needed to improve reapplication after swimming, sweating and towel drying.