Alphabet Soup of Skin Cancer (Part 2)

Hi everyone! I hope you enjoyed your holiday weekend. Now that we have celebrated the official kick-off of summer, I’d like to continue my discussion of skin cancer. Last week, I talked about the characteristics and prevalence of various forms of skin cancer. This week, I would like to talk about prevention.

From news reports to marketing campaigns, we are inundated with the message to “wear sunscreen.” It is valid advice, but I find most people do not really understand the letters printed across sunscreen labels. SPF…UVA…UVB…huh!? If you are not able to decode these letters and their subsequent numbers, how do you know that you are adequately protecting your skin from radiation from the sun? Let’s shed some light on what these abbreviations mean.

1. SPF: This stands for “sun protection factor.” In theory, this number tells you how many times longer you can stay out in the sun without burning than what you could if you were not wearing the sunscreen. Let’s say you go out in the sun unprotected and you burn in 15 minutes. You decide to try a sunscreen with an SPF of 30. Theoretically, you could stay in the sun for 450 minutes (15 min x 30SPF) before you got the same sunburn.

I don’t know about you, but I have never been able to stay in the sun for nearly 4 hours without experiencing a sunburn. Here’s why: SPF factors are tested in very controlled environments. When sunscreen is applied to a test subject (either a person’s skin or another surface which is used to measure UV light penetration) it is applied at a “thickness” of 2 milligrams per square centimeter. In order to cover the whole body, a person would need to use about 1 ounce of sunscreen (about 1 shot glass full) to achieve that coverage. Most people use half or ¼ of that amount and it’s highly unlikely they are applying the sunscreen evenly over their body. Using less sunscreen reduces the effectiveness of the product. In addition, sunscreen gets gradually worn off with sweating, the rubbing of clothes on the skin, or spending time in water (even “waterproof” sunscreen needs to be regularly re-applied) and radiation from sunlight breaks down the protecting chemicals in that barrier over time. So, more UV rays are penetrating your barrier 2 hours after application than what was making it through in the hour before.

2. UVA and UVB: These terms refer to two specific types of ultraviolet radiation. UVA is ultraviolet light that can cause the skin to age. UVB is the ultraviolet light that is attributed to sunburns and skin cancer. (Think uvA for “aging” and uvB for “burn.”) Because UVB is attributed to burns, it is important to note that SPF only measures protection against UVB rays…it says nothing about protection from UVA rays, which are also harmful.

The Food and Drug Administration (FDA…I know…more letters) is implementing new regulations by the end of this year for more accurate labeling of sun protection products. A sunscreen labeled “broad spectrum” should have an SPF of 15 or higher and should protect against both UVA and UVB rays. I have seen some products that specify they protect against both types of radiation, but anything with an SPF between 2 and 14 will not protect against UVA radiation.

3. Waterproof/Sweatproof: These are terms the FDA is not longer permitting as claims on sunscreen labels, in addition to the word “sunblock.” Manufacturers can no longer make these claims because nothing can offer absolute protection and these terms may mislead consumers to believe they can. If a sunscreen is labeled as water resistant, it must include the amount of time (determined by standard testing) that a person can expect to have the same level of protection while swimming or sweating. (I was surprised to find the labels will say either 40 minutes or 80…no other time limits are permitted.)

I know some people that don’t like to use sunscreen for various reasons such as fear of breakouts, concern about absorbing chemicals into their skin, etc. So, I should address other options available for skin protection when out in the sun. Smart choices in clothing, sunglasses, and hats can offer protection. When it comes to choosing your clothes for a day in the sun, pick something with a tight weave to minimize the light passing through the cloth. If you’re not sure, hold the garment up to a light. The more light you can see through the cloth, the more sunlight will be able to penetrate to your skin. While even a ball cap is better than nothing, wide brimmed hats offer protection over your eyes, ears, and the back of your neck. Also, avoiding time in the sun between 10am and 4pm helps minimize the UV exposure you receive. Not only is this a great time to escape the heat and make a massage appointment (please pardon my shameless plug) but before 10:00 and after 4:00, the sun is lower on the horizon. At these positions, UV light must travel through more of the earth’s atmosphere to reach the surface and so less UV rays make it through the atmosphere to your skin.  Finally, be aware of how your environment can reflect light and expose you to more sunlight. Water, pavement, and the gypsum dunes at White Sands National Monument reflect more light than darker, rougher surfaces, leaving you prone to even more UV exposure.

I hope this information helps you avoid the misery and discomfort of sunburns and clears up confusion from those bottles at the drugstore. Be well and have a great summer!


Robin Faux, LMT (NM lic. 5600) has been practicing and studying massage therapy for more than 10 years. She has a degree in Integrative Medical Massage Therapy and has numerous certifications in techniques designed to relieve pain for her clients. When not massaging, Robin teaches anatomy and physiology to massage therapy students at MTTI in Las Cruces. If you want to get in touch with her, please call 719-650-9349 or email her at