How SPF and broad-spectrum sunscreen tests answer different questions

A sunscreen’s SPF number and its broad-spectrum label answer different questions. Both are connected to tests on the finished product, but neither should be treated as a summary of every kind of protection.

FDA describes the SPF test as a controlled procedure using human test subjects and a solar simulator. The product is applied to a defined skin area at 2 milligrams per square centimeter, then the observed responses on protected and unprotected areas are used to determine the SPF result under the prescribed method. SPF describes sunburn protection; it is not a timer for staying outside.

Broad-spectrum testing addresses UVA protection as well as UVB. FDA’s testing guidance uses a laboratory procedure that evaluates the product’s ultraviolet absorbance across a specified range. A product must meet the applicable test standard to use the broad-spectrum label.

These are explanations of testing requirements, not test results for any particular brand. Read the finished product’s Drug Facts label for the SPF, broad-spectrum status, directions, and warnings that apply to that product.

AREV Daily UV Fluid is in development. Final formula and SPF will be announced after finished-product testing. This article is general sunscreen education, not a claim about our product.

Sources

FDA: Sunscreen labeling and effectiveness testing guide — https://www.fda.gov/regulatory-information/search-fda-guidance-documents/labeling-and-effectiveness-testing-sunscreen-drug-products-over-counter-human-use-small-entity

FDA: Final sunscreen monograph order OTC000006 — https://www.accessdata.fda.gov/drugsatfda_docs/omuf/Order/Final%20Administrative%20Order%20OTC000006_M020-Sunscreen%20Drug%20Products%20for%20OTC%20Human%20Use.pdf

AAD: How to decode a sunscreen label — https://www.aad.org/public/everyday-care/sun-protection/shade-clothing-sunscreen/understand-sunscreen-labels