Not all basal and squamous cell skin cancers can be prevented. But there are ways to reduce your risk of getting skin cancer.

Limit ultraviolet (UV) exposure

The best way to lower the risk of non-melanoma skin cancer is to limit your exposure to strong sunlight. Be "sun safe" when you are outdoors. "Slip! Slop! Slap! … and Wrap" is a catch phrase to remind you of the 4 ways you can protect yourself and those you love from UV radiation: slip on a shirt, slop on sunscreen, slap on a hat, and wrap on sunglasses to protect the eyes and sensitive skin around them from UV light. Here are some more things you can do:

Protect your skin with clothing

Some clothes give more protection than others. Long-sleeved shirts, long pants, or long skirts are the best. Dark colors are better than light colors. A tightly woven fabric protects better than loosely woven clothing. Dry fabric is most often better than wet fabric.

Some clothing is made with built-in UV protection. There are also newer products that can increase the ultraviolet protection factor (UPF) value of clothes you already own. Used like laundry detergents, they add a layer of UV protection to your clothes without changing the color or how the cloth feels.

Wear a hat

A hat with at least a 2- to 3-inch brim all around is best because it protects areas often exposed to the sun, such as the neck, ears, eyes, forehead, nose, and scalp. A shade cap (which looks like a baseball cap with about 7 inches of fabric draping down the sides and back) also is good. These are often sold in sports and outdoor supply stores.

A baseball cap can protect the front and top of the head, but not the neck or the ears. Straw hats are not as good unless they are tightly woven.

Use sunscreen

Use sunscreen and lip balm with an SPF of 15 or higher. Be sure to use enough (a palmful) and put it on again every 2 hours and after swimming or sweating. Use sunscreen even on hazy or overcast days. For it to work best, sunscreen should be put on about 20 to 30 minutes before you go outside.

Don't make the mistake of thinking that because you're using sunscreen, you can stay out in the sun longer. Sunscreen should not be used to gain extra time in the sun, because you will still end up with damage to your skin. You won't reduce your risk that way.

If you want a tan, try using a sunless tanning lotion. These can make you look tan without the danger. You do not have to go out in the sun for these to work. The color tends to wear off after a few days.

Wear sunglasses

Wrap-around sunglasses that absorb at least 99% of the UV rays help protect your eyes and the skin around your eyes.

Stay in the shade

Look for shade, especially in the middle of the day, between the hours of 10 am and 4 pm, when the sun’s rays are strongest. Keep in mind that sunlight (and UV rays) can come through clouds, reflect off water, sand, concrete, and snow, and can reach below the water's surface.

Avoid other sources of UV light

Don't use tanning beds and sun lamps. These also give off UV light and can increase the risk of skin cancer. They are not a safe way to get tan.

Protect children

Use the methods above to protect children from too much sun. Also teach them to protect themselves as they get older.

A word about sun exposure and vitamin D

Doctors are learning that vitamin D has many health benefits. It may even help to lower the risk for some cancers. Vitamin D is made by your skin when you are in the sun. How much vitamin D is made depends on many things, such as how old you are, how dark your skin is, and how brightly the sun shines where you live. At this time, doctors aren't sure what the best level of vitamin D is, or how best to balance the benefits of getting vitamin D from sunlight versus the risks of skin cancer. If you have darker skin or live in a place with little daily sunlight, many experts suggest taking vitamin D by mouth, such as in supplements or certain foods. Most milk has vitamin D added.

Avoid harmful chemicals

Certain chemicals, such as arsenic, can increase a person's risk of skin cancer. People can be exposed to arsenic from well water in some areas, pesticides and herbicides, some medicines, and herbal remedies (arsenic has been found in some herbal remedies imported from China). Certain jobs, such as mining and smelting, can also expose workers to arsenic.

For more information on how to protect yourself and your family from UV exposure, see the American Cancer Society document, Skin Cancer Prevention and Early Detection.