A novel proposal for labelling sunscreens based on compliance and performance.

OBJECTIVE

To propose a new way of classifying sunscreens, which combines the labelled SPF with an objective measure of compliance.

METHODS

The in vitro determination of uniformity of sunscreen application was combined with an in vivo measure of applied thickness to derive a Compliance Factor for each of 10 sunscreens.

RESULTS

The predicted SPF resulting from real-life application of each sunscreen product, which is termed the SPF(in vivo veritas), was calculated from the Compliance Factor and the labelled SPF. It was shown that for a number of products, there is expected to be a significant mismatch between labelled and delivered SPF.

CONCLUSION

We believe that by adopting our proposal, consumers would be given more appropriate guidance on the delivered photoprotection they can expect to receive than relying solely on the labelled SPF.