You can start using sunscreen on a baby at 6 months old. Before that age, both the FDA and the American Academy of Pediatrics recommend keeping infants out of direct sunlight entirely, relying on shade and clothing instead. There is one exception: if shade and protective clothing aren’t available, you can apply a small amount of mineral sunscreen to exposed areas like your baby’s face and the backs of their hands, even before 6 months.
Why the 6-Month Rule Exists
A newborn’s skin is structurally different from an adult’s. The outermost layer is thinner, the protective acid layer on the skin’s surface hasn’t fully developed, and water escapes through the skin at a significantly higher rate. These differences mean that anything applied to a baby’s skin can penetrate more easily and reach the bloodstream in greater concentrations.
The ratio of skin surface area to body weight in newborns is 2.3 times higher than in adults. That means a lotion spread evenly across a baby’s body exposes them to a proportionally much larger chemical dose per pound than the same product would for you. Babies also have limited ability to metabolize and clear those substances from their bodies. For these reasons, sun avoidance is the first-line strategy for infants under 6 months, not sunscreen.
The Exception for Younger Babies
Sometimes shade simply isn’t available. You’re at a family event, crossing a parking lot, or stuck somewhere without tree cover or an umbrella. In those situations, the AAP says it’s acceptable to apply sunscreen to small areas of exposed skin on a baby younger than 6 months, particularly the face and backs of the hands. Use a mineral sunscreen (one with zinc oxide or titanium dioxide), and wash it off once you’re back indoors. If you have any concerns, check with your pediatrician before using sunscreen on a very young infant.
Protecting Babies Without Sunscreen
For babies under 6 months, clothing and shade do the heavy lifting. The AAP recommends lightweight, long-sleeved shirts and long pants made from tightly woven fabrics. Cotton works well because it’s cool and offers decent UV protection. A hat with a brim wide enough to shade the face, ears, and neck is essential.
Stroller canopies, pop-up tents, and beach umbrellas all create portable shade. The most important window to avoid is 10 a.m. to 2 p.m., when UV rays are strongest. Planning outdoor time for early morning or late afternoon makes a significant difference in your baby’s exposure.
Choosing the Right Sunscreen After 6 Months
Once your baby hits 6 months, sunscreen becomes a regular tool in your sun-safety routine. Not all sunscreens are equal for babies, though. Pediatricians and dermatologists consistently recommend mineral sunscreens containing zinc oxide or titanium dioxide for young children and anyone with sensitive skin. These ingredients sit on top of the skin and physically block UV rays rather than being absorbed into the body.
Chemical sunscreens work differently. They absorb into the skin and convert UV radiation into heat. A study published in JAMA found that ingredients in some chemical sunscreens enter the bloodstream at levels high enough to warrant further investigation. Mineral sunscreens have not been shown to do this. The AAP also specifically recommends avoiding oxybenzone, a common chemical filter, because of concerns about mild hormonal effects.
Look for a sunscreen labeled “broad spectrum” with an SPF of at least 30. Broad spectrum means it protects against both UVA rays (which cause long-term skin damage like wrinkles and sunspots) and UVB rays (which cause sunburn and are more directly linked to skin cancer). SPF 30 blocks about 97% of UV rays, which is sufficient for most situations.
How to Apply Sunscreen on a Baby
Apply sunscreen about 20 minutes before heading outside so it has time to bind to the skin. Cover every exposed area, and pay special attention to the spots parents commonly miss: the tops of the ears, the back of the neck, and the tops of the feet. These areas burn quickly and are easy to overlook.
Reapply every two hours. If your baby goes in the water or gets toweled off, reapply immediately, even if it hasn’t been two hours yet. Sweating and wiping can remove sunscreen faster than you’d expect.
Patch Testing Before First Use
Baby skin is more reactive than adult skin, and even mineral sunscreens can occasionally cause irritation. Before using a new sunscreen on your baby for the first time, test it on a small patch of skin, like the inside of the wrist or the inner arm. Apply a small amount to a quarter-sized spot and watch for redness, itching, or swelling over the next day or two. If your baby’s skin reacts, try a different formulation. If no reaction appears, the sunscreen is likely safe to use more broadly.
If your baby is older than 6 months and shows sensitivity to sunscreen in general, the AAP recommends choosing a formula with only zinc oxide or titanium dioxide as the active ingredients, as these tend to be the least irritating options available.
Sunscreen Is Only Part of the Plan
Even after 6 months, sunscreen works best alongside other protective measures. Clothing still blocks more UV than any lotion. Tightly woven, long-sleeved shirts and pants cover the most skin surface area and reduce how much sunscreen you need to apply. A wide-brimmed hat and sunglasses with UV protection round out the coverage. Staying in shade during peak sun hours remains the single most effective way to limit UV exposure at any age.