It’s summertime, the sun is beating down and your family wants to play outside. What number of SPF sunscreen should you use?
The short answer is SPF 30, applied every 2 hours.
The longer answer is a bit more complicated, but knowing more about ultraviolet rays, SPFs, suntan lotions, and the risk for skin cancer can help you understand how to make this a safe summer for you and your family.
What does SPF mean?
These 3 letters on the tube of suntan lotion stand for Sun Protection Factor. It’s a numbering system used to measure how well the lotion protects you from getting a sunburn. But not all lotions are measured equally because of their relationship with ultraviolet rays.
What are ultraviolet (UV) rays?
Ultraviolet rays emanate from the sun and man-made devices like tanning beds. There are 3 kinds of UV rays, each with a different wavelength:
- UVA rays have a relatively long wavelength and account for 95% of UV radiation that reaches the Earth’s surface
- UVB rays have a medium-long wavelength and are most harmful to humans. Much of the UVB rays are filtered out by the ozone layer in Earth’s atmosphere, but they still reach the Earth. Man-made chemicals can deplete the ozone, thereby letting more harmful UVB rays reach the Earth’s surface
- UVC rays have a short wavelength. They could be the most harmful to humans, but they are completely filtered out by Earth’s atmosphere
How harmful to our health are UV rays?
According to the American Cancer Society, “Exposure to UV rays can cause premature aging of the skin and signs of sun damage such as wrinkles, leathery skin, liver spots, and more. UV rays can also cause eye problems, such as causing the cornea (the front of the eye) to become inflamed or burned.”
What number of SPF is best for preventing sunburn?
As mentioned above, if you use suntan lotion with SPF 30 and apply it every 2 hours, even if you don’t get into the water, you should be okay. SPF 30 blocks 97% of UVB rays while SPF 50 is only a little better, blocking 98% of UVB.
Please note that only UVB rays are blocked by regular suntan lotion, no matter the SPF number. To also block the more prevalent UVA rays, you need to use a “broad spectrum” lotion. Using one with at least an SPF 30 will help protect you and your family… to a point.
What else can you do to minimize the effects of the sun?
The best way to lessen your risk for sunburn and sun poisoning is to stay out of the sun as much as you can, especially during the hours between 10 am and 4 pm when the sun is at its peak and the sun rays are most direct. You should also wear lip balm, sunglasses and a wide-brim hat to protect your eyes, your scalp and your face. Wearing lightweight long sleeve shirts and pants will also protect your arms and legs.
Finally, drink a lot of water on hot days to stay hydrated and keep your body healthy during those sunny summer days!