There are many things to love about spray sunscreens: They often feel lighter on the skin and are easier to apply than their lotion counterparts. But if you think just a few haphazard spritzes will provide adequate protection against the sun’s harmful rays, think again.

Daily sunscreen use is vital, said Dr. Maral Kibarian Skelsey, a clinical associate professor of dermatology at Georgetown University Medical School. It prevents sunburn and protects your skin from long-term sun damage, which can cause wrinkles and sun spots and raise your risk of skin cancer, the most common form of cancer in the U.S.

Yet many Americans don’t apply sunscreen often enough. In a 2020 survey from the Centers for Disease Control and Prevention, just 12% of men and 29% of women said they always used sunscreen when they were outside for more than one hour on a sunny day.

Here’s what to know about spray sunscreens, and how to use them effectively.

Benefits, drawbacks

Spray sunscreens are popular because they’re so easy to use, said Dr. Jean Charles, a dermatologist in Cedar Park, Texas. Spraying lets you target large swaths of the body, including hard-to-reach spots like your back.

Sprays tend to be lighter, less “sticky, oily and heavy,” and less likely to leave a white residue than lotions, said Dr. David Kim, a cosmetic dermatologist in New York City.

But spray sunscreens can pose challenges. Sometimes, it’s hard to tell if the sunscreen is evenly distributed, Skelsey said. When you apply it on a windy day, more might float into the air than onto your body.

“There’s always a risk that you are going to miss spots,” Charles said. With lotions, you can see where it’s going.

Many popular products also contain flammable gases such as propane, butane or isobutane, which propel the sunscreen onto your skin and could pose a burn hazard if applied or worn while smoking or near an open flame.

Some spray sunscreens also contain alcohol, which can irritate and dry out the skin, Charles said.

What to look for in a spray sunscreen

Spray sunscreens have the same active ingredients as lotions, Skelsey said, so they should be just as protective as lotions — if used correctly.

As with lotions, adults and children older than 6 months should use broad-spectrum spray sunscreens with an SPF of 30 or higher, Charles said.

If you have sensitive skin, Skelsey recommended mineral-based spray or lotion sunscreens with zinc oxide or titanium dioxide as their active ingredients; they’re less likely to cause irritation or allergic reactions.

A more expensive, high-end or luxury product is not necessarily better than a cheaper one, Skelsey said.

How to use

According to the American Academy of Dermatology, you need about an ounce of sunscreen to cover your entire body. This amount — about a shot glass’s worth of sunscreen — can be hard to gauge with a spray, so the academy recommends holding the nozzle about an inch from your body and spraying until your skin glistens.

Don’t forget your feet, ears, neck, hands and scalp, Skelsey said. The most important step is to rub the sunscreen in after applying it. If you don’t, the skin may not be evenly covered, Kim said. You can also spray it onto your hands and smear it on your body, Charles added.

Reapply it as you would any sunscreen, every two hours — or more frequently if you’re swimming or sweating, Skelsey said. “It’s important enough that you should really set a timer.”