How to Read a Sunscreen Label: SPF, Broad Spectrum, Water Resistant and Expiration Dates
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How we wrote this: A plain-English summary of the FDA consumer page Sunscreen: How to Help Protect Your Skin from the Sun, checked October 29, 2026. In the U.S., sunscreens are regulated as drugs, so they carry a Drug Facts label.
SPF: protection from sunburn, not a timer
The FDA says SPF measures how much UV exposure it takes to cause sunburn with the sunscreen compared with without it. It mainly reflects UVB protection. Higher SPF values (up to 50) give more sunburn protection.
A common myth: SPF 15 does not mean you can stay out 15 times longer. The FDA explains SPF relates to the amount of solar exposure, not the time. Midday sun is far stronger than early morning sun.
Broad spectrum
Broad-spectrum sunscreens protect against both UVA and UVB. Not all sunscreens are broad spectrum, so check the label. The FDA recommends broad spectrum, SPF 15 or higher. Products that aren't broad spectrum, or that are under SPF 15, must carry a "Skin Cancer/Skin Aging Alert" saying they only help prevent sunburn.
"Water resistant," never "waterproof"
The FDA says no sunscreen is waterproof. All of them wash off eventually. Products labeled water resistant must say whether they stay effective for 40 or 80 minutes of swimming or sweating.
How to use it (FDA tips)
- Apply 15 minutes before going out.
- Use about one ounce, roughly a shot glass, to cover an average adult's or child's body.
- Reapply at least every two hours, and more often when swimming or sweating.
- Don't forget ears, the back of the neck, the tops of feet and an exposed scalp.
- Limit sun between 10 a.m. and 2 p.m., and cover up with clothing, sunglasses and a broad-brimmed hat.
- Infants under 6 months: sunscreen isn't recommended. Keep them out of the sun and ask a doctor.
Storage and expiration
- Keep containers out of direct sun, wrapped in a towel or in the shade.
- Don't use expired sunscreen. If there's no expiration date, don't use it if you bought it more than three years ago.
Spray sunscreen safety
Some sprays contain flammable ingredients like alcohol, and these must carry a flammability warning. Don't smoke or go near grills, candles or open flames while applying or wearing them. Never spray directly on your face. The FDA also says not to use any recalled sunscreens.
Also see: the UV Index, beach day sun protection checklist.