Broad Spectrum Test

The FDA’s Broad Spectrum Test is an in vitro test that looks at the critical wavelength of the formulation. (The critical wavelength is a measure of the breadth of the UV absorbance curve.)

To pass the test, the sunscreen formulation must have a critical wavelength of at least 370 nm.

If a sunscreen qualifies, it is allowed to display the label “Broad Spectrum SPF __.” (The SPF number would be shown in the underlined area.) The SPF number must be listed after “Broad Spectrum,” a new labeling rule as of 2011.