Expand Sunscreen effectiveness depends on a number of factors, including the SPF value, if the product provides broad spectrum protection, level of water resistance, and whether the product is used as directed. No matter what the active ingredients, all FDA-approved sunscreen ingredients work by scattering, reflecting or absorbing UV rays. There is no difference in efficacy between sunscreens with organic or inorganic actives, as they all must be formulated to achieve their SPF label claim. All sunscreens in the United States must be tested for SPF performance using the same FDA designated clinical tests. Testing methods used to develop sunscreen shopping guides (e.g. Consumer Reports, the Environmental Working Group) may not be consistent with those used by FDA, and therefore may not be accurate indicators of a sunscreens’ SPF designation.