During the winter, the sun seems harmless. But even on an overcast day, reflected rays from the snow still cause significant harm. Sunscreens help, but the product labels are confusing. Understanding sunscreens help to demystify their proper use and selection.  

There are two kinds of harmful ultraviolet rays, UV-A and UV-B. UV-B causes sunburn and cancer. UV-A causes long-term damage like wrinkles. Sunscreens with both UV-A and UV-B protection are labelled “broad spectrum,” and work by reflecting and absorbing UV radiation. Common ingredients include zinc and titanium.  

Some sunscreens are better than others at blocking UV rays. The Sun Protection Factor, or SPF scale, shows which sunscreens are better at preventing sunburn. Higher numbers mean better protection, but there are confusing issues. Many consumers misinterpret the meaning of the SPF number and spend too much time in the sun.

To clarify, the SPF number compares the length of time to develop a burn on protected versus unprotected skin. If it takes twice as long to develop a burn on protected skin (say 60 minutes as opposed to 30), the SPF is 2. If it takes 15 times as long, the SPF is 15. This does not mean you can spend 15 times as long in the sun! The SPF system is a quick reference for effectiveness, and should never replace common sense.  

Another “sticky” point is following the label instructions. Labels will tell you how much sunscreen to apply to match the thickness slathered on the test subject. Most people find the suggested quantity very excessive and will never achieve the stated SPF.

To top the list of SPF gripes, the value on the label is not a measure of UV protection! A sunscreen with an SPF of 30 will block 97% of UV-B, yet an SPF of 15 still blocks 93%. That’s why most dermatologists will say there is little extra benefit over an SPF of 30. For most people strolling to their car at lunch time, an SPF of 15 is likely adequate. For midday sun exposure or outdoor activities more than thirty minutes, an SPF of at least 30 is recommended.

Waterproof and Sweat-proof? . . . Nay-nay says the FDA! Sunscreen makers can no longer make these claims. They CAN state how long the benefits will last before re-applying, depending on activities . 

The best advice is to use common sense to avoid the damaging rays from the sun. Sunscreens are not a license to fry! Avoiding mid-day sun and wearing sun protective clothing remain our best option. Never use sunscreen on a baby. It’s best to keep them out of the sun.  

Choose your sunscreen wisely. Look for the words broad spectrum, check the SPF number, and remember to read the directions to best suit your outdoor needs.