chapter  40
20 Pages

Balancing UV-A and UV-B Protection in Sunscreen of Efficacy, and Clear Communication to Consumers

Introduction 808

Background on the Requirements for UV-A/UV-B Proportionality 809 Protection Minimums for Proportional UV-A/UV-B Protection 811 Beyond the Minimum Balance Requirements: Extra UV-A Protection 813

Identification and Communication of Two Distinct Levels of

UV-A Protection 813

The Need to Measure Both Breadth and Quantity of Protection 815

Testing Formulations to Evaluate the Reproducibility of the PFA and

Persistent Pigment Darkening UV-A Test Methods, with Additional

Assessment of Broadness 816

Results 817

Discussion 818

Conclusions and Recommendations 823

References 824

INTRODUCTION

In 1996, industry submitted to Food and Drug Administration (FDA) for

consideration an in vitro UV-A test method called Critical Wavelength (1).

That method measured the broadness of the protection provided by a sunscreen

product, but did not address either the magnitude of protection or the issue of

the appropriate proportionality of UV-A to UV-B protection. The importance

of assessing the quantity of UV-A protection provided by sunscreen products

was highlighted by the FDA in correspondence relating to the approval of the

combination of avobenzone with certain other active ingredients (2,3). In that

correspondence, the Agency asked for additional clinical UV-A protection data

beyond Critical Wavelength to support the UV-A efficacy of those ingredient

combinations. The data that the Agency requested was to be based on the in

vivo Protection Factor A (PFA) test method (4).