• MDermatology

The serious business of SPF

Did you know that May is "Skin Cancer Awareness Month"?! According to the American Academy of Dermatology, 1 in 5 Americans will develop a skin cancer in their lifetime. Intermittent sun exposure in childhood and during adolescence may increase risk of skin cancer. Even one blistering sunburn during childhood can nearly double a person’s chance of developing a melanoma later in life. These are all reasons as to why daily sunscreen use and diligent sun protection is essential to prevent skin cancer and early skin aging.

Sunscreens are available in two broad categories:

Physical/Mineral vs Chemical sunscreens. Chemical sunscreens contain organic compounds such as oxybenzone and avobenzone which absorb UV rays as they attempt to enter the skin. Whereas, physical sunscreens contain active mineral ingredients such as titanium dioxide and zinc oxide, which scatter and reflect UV rays.

Amount of SPF:

In general, it is recommended to apply a nickel-sized amount of sunscreen to the entire face. If you are at the beach or pool, it is recommended to apply 1 shot glass amount of sunscreen to the entire exposed skin. Wearing SPF during cloudy or overcast days is just as important as wearing it on sunny days. In general, the sun’s rays are strongest typically around 10am to 2pm and so it is recommended to be be diligent about SPF and sun protection during this time of day. A helpful tip: When your shadow is shorter than you are….seek shade!

Is a higher number SPF better than a low-number one?

SPF, also known as sun protective factor, is important to pay close attention to. his basically measures how much UV light a sunscreen can filter out. An SPF of at least 30 is to date the recommendation of dermatologists. An SPF of 30 blocks 97 percent of the sun’s UVB rays. Having a high-number SPF does not protect you for a longer period of time, but instead has slightly more coverage (98%+ coverage from the sun’s UVB rays). With that being said, no sunscreen in reality can block 100 percent of the sun’s UVB rays.

Many individuals purchase a higher SPF in hopes that they don’t have to reapply. In reality, a high-number SPF does not mean that you can spend additional time outdoors unprotected. Reapplication is essential, especially when after being in the water or after a vigorous work-out (sweating).

With so many sunscreen brands out there, what should I look for? Where do you even start? Well, the first step is to look at the label...and make sure your sunscreen says “broad spectrum” meaning it protects against both UVA and UVB rays.

Another helpful tip is to check the expiration date. Many people keep their sunscreens for multiple seasons and don’t realize that it’s actually expired, and an expired sunscreen is not going to protect your skin as effectively.

Safety of SPF:

Can the sunscreen be absorbed into my skin and get into my blood? This is a common question I come across as a dermatologist almost on a daily basis, especially with increasing reports in the media regarding sunscreen absorption and risk of cancer. What we do know is that there are some reports revealing that certain chemical sunscreens may be potentially absorbed into the blood at higher levels than previously thought; however, there are no studies to date showing that sunscreen has been linked to cancer.

SPF clothing:

UV-protective clothing contains ultraviolet protection factor (UPF) which helps to block both UVA and UVB rays. AmberNoon is a clothing designed by Dr. Erum Ilyas wherein each piece of clothing protects and blocks significant amount of UV rays and has an impressive UPF rating of 50+!

Disclaimer : This page contains an affiliate link to products. We may receive a commission for purchases made through this link.

Montgomery  Dermatology, LLC

Phone (610) 265-1166

FAX (610) 265-1186

860 1st Ave #8b, King of Prussia, PA 19406
10000 Shannondell Drive, Audubon, PA 19403

  • Black Instagram Icon

©2019 by Proudly created with