Ultraviolet (UV) rays - from the sun and other sources like tanning beds – are the number one cause of skin cancer. Too much exposure can also cause sunburn, eye damage, and premature wrinkles. But shielding your skin with clothing, broad-spectrum sunscreen with a sun protection factor (SPF) of at least 30, and staying in the shade can help lower your risk.
Take these steps to stay sun-safe:
- Cover up: When you are out in the sun, wear clothing and a wide-brimmed hat to protect as much skin as possible. Protect your eyes with sunglasses that block at least 99% of UV light.
- Use a broad-spectrum sunscreen with an SPF of at least 30: Reapply at least every 2 hours, as well as after swimming or sweating.
- Seek shade: Limit your direct exposure to the sun, especially between 10 a.m. and 4 p.m., when UV rays are strongest.
- Avoid tanning beds and sunlamps: Both can cause serious long-term skin damage and contribute to skin cancer.
Choosing the right sunscreen
While you should use sunscreen every day of the year, it’s even more important during the summer, when the days are longer, the sun is stronger, and it’s easier to spend more time outdoors. When choosing sunscreen, read the label before you buy. US Food and Drug Administration regulations require the labels to follow certain guidelines:
- Choose a sunscreen with “broad-spectrum” protection. Sunscreens with this label protect against both UVA and UVB rays. All sunscreen products protect against UVB rays, which are the main cause of sunburn. But UVA rays also contribute to skin cancer and premature aging. Only products that pass a test can be labeled “broad spectrum.” Products that aren’t broad spectrum must carry a warning that they only protect against sunburn, not skin cancer or skin aging.
- Choose a sunscreen with a sun protection factor (SPF) of at least 30. The SPF number is the level of protection the sunscreen provides against UVB rays. Higher SPF numbers do mean more protection, but the higher you go, the smaller the difference becomes. SPF 15 sunscreens filter out about 93% of UVB rays, while SPF 30 sunscreens filter out about 97%; SPF 50 sunscreens filter about 98%, and SPF 100 filter about 99%. No sunscreen protects you completely. The FDA requires any sunscreen with an SPF below 15 to carry a warning that it only protects against sunburn, not skin cancer or skin aging.
- “Water resistant” does not mean “waterproof.” No sunscreens are waterproof or “sweat-proof,” and manufacturers are not allowed to claim that they are. If a product’s front label makes claims of being water resistant, it must specify whether it lasts for 40 minutes or 80 minutes while swimming or sweating. For best results, reapply sunscreen at least every 2 hours and even more often if you are swimming or sweating. Sunscreen usually rubs off when you towel yourself dry, so you will need to put more on.
Is sunscreen safe?
Some health groups, consumer groups, and environmental groups have raised concerns over ingredients found in some sunscreens and their potential effects on people and nature.
According to Len Lichtenfeld, MD, interim chief medical officer of the American Cancer Society, “The experts who have looked at the data have concluded that the potential risk of not using sunscreen far outweighs the risks of using sunscreen.” Lichtenfeld, who has had skin cancer himself, says he uses sunscreen on his face every day. He recommends people buy and use sunscreens that are sold and marketed in the US because of limited information about the safety and effectiveness of sunscreens produced in other countries.
Sunlight consists of two types of harmful rays that reach the earth - UVA rays and UVB rays. Overexposure to either can lead to skin cancer. In addition to causing skin cancer, here’s what each of these rays do:
- UVA rays (or aging rays) can prematurely age your skin, causing wrinkles and age spots, and can pass through window glass.
- UVB rays (or burning rays) are the primary cause of sunburn and are blocked by window glass.
The United States Department of Health & Human Services and the World Health Organization’s International Agency of Research on Cancer have declared UV radiation from the sun and artificial sources, such as tanning beds and sun lamps, as a known carcinogen (cancer-causing substance).
There is no safe way to tan. Every time you tan, you damage your skin. As this damage builds, you speed up the aging of your skin and increase your risk for all types of skin cancer.
Dermatologists recommend using sunscreen every day when you are outside, not just during the summer. If you are using sunscreen every day and in the correct amount, a bottle should not last long. If you find a bottle of sunscreen that you have not used for some time, here are some guidelines you can follow:
- The FDA requires that all sunscreens retain their original strength for at least three years.
- Some sunscreens include an expiration date. If the expiration date has passed, throw out the sunscreen.
- If you buy a sunscreen that does not have an expiration date, write the date you bought the sunscreen on the bottle. That way, you’ll know when to throw it out.
- You also can look for visible signs that the sunscreen may no longer be good. Any obvious changes in the color or consistency of the product mean it’s time to purchase a new bottle.