WASHINGTON, June 9 -- For the better part of three decades, Americans reaching for sunscreen have been handed a weaker shield against the sun than the one sold routinely in European and Asian pharmacies. That gap began to close on Tuesday, when the Food and Drug Administration cleared bemotrizinol, a broad-spectrum ultraviolet filter, for use in over-the-counter sunscreens sold in the United States. The decision, confirmed this week, marks the first new sunscreen active ingredient the agency has added to its monograph since the late 1990s.

Bemotrizinol is not new to the world. It has been used safely in Europe, Australia and parts of Asia for decades, valued because it absorbs both UVA and UVB rays, passes only minimally through the skin...