Wear suitable clothing and spend time in the shade when the sun's at its hottest. When buying sunscreen, the label should have: a sun protection factor (SPF) of at least 30 to protect against UVB.
A sunscreen with SPF 30 will protect you from around 96.7% of UVB rays, whereas an SPF of 50 means protection from about 98% of UVB rays. Anything beyond SPF 50 makes very little difference in terms of risk of sun damage, and no sunscreens offer 100% protection from UVB rays.
But the truth is that higher-SPF products are only marginally better at shielding you from UVB, according to both the EWG and the Skin Cancer Foundation. SPF 30 blocks nearly 97% of UVB radiation, SPF 50 blocks about 98%, and SPF 100 blocks about 99%.
Dermatologists recommend using an SPF of at least 30, which Adarsh Vijay Mudgil, MD, a dermatologist practicing in New York, calls "the magic number". SPF 15 blocks about 93 percent of UVB rays, while SPF 30 blocks about 97 percent of UVB rays.
SPF 30 is the most common level for most people and skin types. No sunscreen can block all UV rays, but what we do know is: SPF 15 blocks 93% of UVB rays, SPF 30 blocks 97% of UVB rays and SPF 50 blocks 98% of UVB rays. So, the difference between 30 and 50 is about 1 percent.
"Pigmented skin types – those which rarely burn and tan easily – usually Asian or black skin – are relatively more protected than fair skin types from UV radiation due to melanin. Therefore, wearing a sunscreen with SPF 15-30 is likely to be sufficient."
Here's another way to think about all this: As a general rule, SPF 15 protects you against 93 percent of UVB rays, SPF 30 blocks 97 percent, and SPF 50 blocks 98 percent of UVB rays. Higher than SPF 50 won't offer you any significant extra protection—if anything, it just gives people a false sense of security.
Sunbathers often assume they get twice as much protection from SPF 100 sunscreen as from SPF 50. But the extra protection is negligible. Properly applied SPF 50 sunscreen blocks 98 percent of UVB rays; SPF 100 blocks 99 percent.
Put another way, if your unprotected skin would take ten minutes to show signs of burning, then properly applying SPF 30 sunscreen would slow the rate of burning to the point where it would take 30 times longer, or 300 minutes in total. SPF 15 would take 150 minutes, while SPF 50, 500 minutes.
Wearing a chemical- or physical-based sunscreen may help prevent the sun's rays from causing photoaging and skin cancer. It may still be possible to get a slight tan, even if you do wear sunscreen. However, no amount of deliberate tanning is considered safe.
The difference between a SPF 40 is you block out 97.5% of UVB radiation and SPF 50 blocks 98%. This is a very small difference for the cost of purchasing a SPF 50. More important than using a super high SPF is using enough sunscreen.
The SPF rating only refers to UVB rays. An SPF 15 sunscreen blocks 93% of UVB radiation, and SPF 30 blocks 97%. After that, the difference in protection is small. SPF 50 blocks 98%, and SPF 100 stops 99% of UVB rays from reaching your skin.
SPF stands for Sun Protection Factor. In theory, an SPF 50 sunscreen would allow users to stay out in the sun fifty times longer than they normally could without sunscreen, while SPF 30 would imply that users can stay out thirty times longer before getting sunburned.
Decrease your risk of skin cancers and skin precancers.
Regular daily use of SPF 15 sunscreen can reduce your risk of developing squamous cell carcinoma (SCC) by about 40 percent, and lower your melanoma risk by 50 percent. Help prevent premature skin aging caused by the sun, including wrinkles, sagging and age spots.
When applied correctly, SPF 25 blocks 96% of UVB rays that come in contact with your skin. So yes, for everyday use, an SPF 25 is enough to keep you safe.
SPF30 sunscreen with UVA rating of 4-5 stars is considered a good standard of sun protection. Sunscreens with really high SPFs, such as SPF 75 or SPF 100, do not offer significantly greater protection than SPF 30 and mislead people into thinking they have more protection than they actually do.
In theory, sunscreen with super-high SPF should give you the best protection against damaging UV radiation. But in practice, it may not work that way. In fact, some experts say using super-high-SPF sunscreens could lead to more UV exposure — upping your risk for both burns and skin cancer.
The U.S. FDA is working on setting a limit to SPF promises on sunscreen labels, but for now, the Canadian Dermatology Association advises Canadians to aim for an SPF of at least 30.
While sunscreen with a higher SPF technically blocks out more UV rays, there are diminishing returns as the number climbs. There's a big difference between SPF 10 and SPF 20 but not as big of a difference between SPF 30 and SPF 60. Also, a higher SPF does NOT mean that it needs to be applied less frequently.
As non-dermatologists, though, we're comfortable touting a summer tan as a positive thing—when you follow the rest of this advice and get said tan ever so gradually. “Everyone should be using at least SPF 30 with broad spectrum coverage daily, regardless of whether or not you plan to spend dedicated time outdoors,” Dr.