Sun Safety Tips on SPF & Applying Sunscreen

There is nothing like the first sunny days of spring to inspire us to strip off layers of clothing and turn our faces toward the sun. While temperatures may not even be out of the 50s, it is important to remember that the sun is still producing ultraviolet (UV) rays that can damage your skin. One of your best defenses against damage in the form of sunburn, fine lines, wrinkles, discoloration, and skin cancer this spring—and all year long—is sunscreen.

Because overexposure to the sun’s ultraviolet rays is the most important preventable factor in the development of skin cancer, it is important to choose and use sunscreen wisely. 

Among your first considerations when choosing a sunscreen should be a product’s SPF level and broad-spectrum qualities. Here is why they matter:

SPF

SPF stands for ‘sun protection factor.’ An SPF number tells you the amount of time that a product will protect you from getting a sunburn, specifically from the sun’s UVB rays. For example, if you begin to burn 20 minutes after being in the sun with no sunscreen, using an SPF 30 sunscreen will increase that time to 600 minutes (20 minutes x 30 SPF).

While sunscreen is available with SPF levels of 15, 30, 50, and 100, it is always a good idea to reapply every two hours, especially if you are active outdoors.

Broad Spectrum

Broad spectrum refers to products that protect you from both UVA and UVB rays, both of which can damage skin. UVA rays are associated with skin aging while UVB are associated with skin burning. That said, both UVA and UVB rays can lead to skin cancer. Only products labeled broad-spectrum offer protection from both types of rays.

Of course, no matter how expensive or high the SPF level of a sunscreen is, it will not work if you do not use it properly.

As a rule, one ounce of sunscreen applied over the body is enough for most people (for a frame reference, one ounce is about a shot glass-worth’s). For the face, an additional nickel-sized dollop should be applied. Using less than these recommended amounts on your face or body means getting less protection. And because your lips are an important part of your face, invest in an SPF lip balm and reapply whenever you reapply your sunscreen.

The Skin Cancer Foundation recommends applying sunscreen 30 minutes before going outside (even on cloudy days), then reapplying every two hours and immediately after swimming or sweating. Be aware that no sunscreen is waterproof, only water-resistant. If you are spending time in the water, pay special attention to the clock and reapply as soon as you get out.

A special note to anyone with small children…

If you have a child less than six months old, it is best to keep them out of the sun rather than applying sunscreen to their delicate skin. When outside, make sure their clothing covers their tender arms and legs and use a hat to protect their face. Whenever possible, use umbrellas or other sunshades to minimize their exposure and avoid direct sunlight between the hours 10 a.m. and 2 p.m. 

One final thought before you head outside is that sunscreen does have an expiration date. Sunscreens are formulated to have a shelf life of up to three years when stored in a cool dry place. The three-year life applies whether they have been opened or not. Sunscreens stored in direct sun or high heat (think of that bottle so conveniently kept in your car) will degrade faster and not offer the level of protection you anticipate. In other words, taking good care of your sunscreen means it will take good care of you.

Lixia Ellis, MD, PhD is dermatologist at SVMC Dermatology.