News Coverage
Deciphering ABCs of SPF
Published July 15, 2008
A recent study that found most name-brand sunscreens offer more promises than sun protection doesn't worry local dermatologists.
What does concern them is the way people use the products.
We don't use enough of it. We don't reapply often, if at all. We don't use it consistently. We wait until we get where we're going before putting it on. We don't let it dry long enough.
That people are confused about application isn't surprising given the alphabet and number soup — UVB, UVA, SPF 15, 30, 45, 80 — associated with sunscreen, which is not the same as sun block, dermatologists said. Most of us are not sun protection savvy.
“People are totally confused about which one, how much, how often,” said Dr. Richard Fried, a Lower Makefield dermatologist.
Americans know sun protection is important. They are expected to spend more than $1 billion on products this year, a market that has grown 10 percent annually since 2004.
Meanwhile, the Centers for Disease Control and Prevention found U.S. sunburn rates increased from 32 percent to 34 percent between 1999 and 2004. Skin cancer rates in the United States are rising, while other cancer rates are stable or declining, medical statistics show.
This month a Washington, D.C., environmental research and advocacy group released a study that found most commercial-brand sunscreens do not provide effective, broad-spectrum sun protection.
The Environmental Working Group wants the Food and Drug Administration to immediately implement changes in sunscreen labeling, requiring manufacturers to give more detailed information about the level of sun protection. The changes are scheduled to go into effect next year.
The group analyzed the efficacy and possible health hazards for more than 900 commercial sunscreens and found one in eight did not protect against ultraviolet A (UVA) rays, which make up about 95 percent of sunlight. UVA rays are associated with tanning, aging skin, and studies now strongly suggest they are linked to cancer.
For 30 years, the FDA's sun protection factor (SPF) rating has been based on a product's ability to block only ultraviolet B (UVB) rays — those known to cause sunburn. Scientists know people who have multiple sunburns face a higher risk for skin cancers later in life.
The UVB rays are more powerful than UVA rays, meaning they do damage faster but cannot penetrate beyond the superficial skin layers; UVA light penetrates windows of cars and buildings, whether the sun is out or not, and it leaves no visible marks on your skin
So a person wearing a high SPF sunscreen can stay in the sun longer without experiencing the hot, red skin that warns damage is occurring. But it doesn't protect from the high dose of UVA light you also get.
Dermatologists say you can't blame the FDA or sunscreen manufacturers entirely.
“It is really an indictment of quantity of application rather than effectiveness of product itself,” said Fried.
He called it a “huge shortcoming” in the study that the Environmental Working Group didn't address Americans' general lack of good sunscreen habits.
Sunscreens, even ones with some UVA blockers, lose effectiveness after two or three hours at the longest. They must be reapplied to provide continued protection.
While most people use sunscreen and sun block synonymously, they provide different levels of protection, added Doylestown dermatologist Dr. Robert Willard, a skin cancer specialist. Sunscreens protect the skin by chemically absorbing sunlight; sun blocks physically deflect the sunlight. “It's like wearing clothes; it blocks out the sun all together,” Willard said.
Traditional sun blocks are thicker textured products that don't blend into the skin, leaving behind white patches.
New nanoparticle technology allows substances such as zinc oxide or titanium dioxide — two of the most effective sun block ingredients — to be pulverized into tiny particles allowing people to avoid the familiar white nose, lifeguard look.
The particles are chemically inactive, so there is no concern about chemical exposure, Fried said.
The theoretical concern is what if these nanoparticles were somehow inhaled into the lungs or otherwise enter the body, Fried said. Could this cause allergic or other medically serious reactions?
The FDA approves sunscreen ingredients as safe, and Fried said he is unaware of data suggesting that people who use sunscreen regularly face a higher risk of health problems.
“It's an area I believe we must follow closely,” Fried said. “However, the benefits of sun protection afforded by these products are so numerous ... that we are, as a profession, obligated to continue endorsing their use.”
Bensalem dermatologist Dr. Wayne Marley, also a skin cancer specialist, agreed that most of the new broad spectrum sunscreens don't provide enough UVA protection. But some is better than none.
“If you don't have something that is blocking UVA, you're only walking around with half your clothes on,” he said.
The Associated Press contributed to this story. Jo Ciavaglia can be reached at 215 949-4181 or jciavaglia@phillyBurbs.com.
Sun screen tips
HOW THE SPF RATING SYSTEM WORKS
The SPF is how long a person can spend in the sun to reduce the risk of burning. If a person with a light complexion turns pink in 10 minutes in the direct sun, a sunscreen with an SPF of 30 would protect for 300 minutes — roughly five hours — before the skin turns pink. With an SPF of 15, the same person has 150 minutes of protection — roughly 21/2 hours. These ratings apply only to UVB rays. There is no widely accepted comparable SPF rating for UVA sunscreens.
IS IT WATERPROOF?
Waterproof sunscreens are effective in water for about 80 minutes. But, if you get out and towel dry, you need to reapply for full protection.
DID YOU KNOW?
# Buy new sunscreen every year.
# Apply your sunscreen at least 20 minutes before you go outside.
# An SPF factor of 15 protects against 95 percent of UVB rays; an SPF factor of 25 blocks 97 percent of UVB rays and an SPF of 40 blocks 98 percent of UVB rays.
# If you use bug repellent, apply it at least 15 minutes after sunscreen to reduce the pesticide soaking into the skin.
# Some sun sensitizing medications (thiazide, diuretics, some antibiotics and antidepressants) require heavier sunscreen application and more often.
DERMATOLOGISTS RECOMMEND:
# An SPF of 15 to 40, with broad spectrum protection. Look for a product that includes helioplex or mexoryl, which protect against UVA rays.
# At least 7 percent zinc oxide or titanium dioxide for broad spectrum protection. Look for active ingredients such as Parsol 1789, benzone, avobenzone
WHAT SHOULD I CHOOSE?
These commercial sunscreens are recommended by the Environmental Working Group:
Blue Lizard (anything without oxybenzone)
California Baby (anything with SPF 30+)
CVS brand with zinc oxide
Jason Natural Cosmetics Sunbrellas mineral-based sun block
Kiss My Face “Paraben Free” series
Neutrogena Sensitive Skin sun block
Olay Defense Daily UV Moisturizer (with zinc)
SkinCeuticals Physical UV Defense
Solar Sense Clear Zinc for Face
Walgreens Zinc Oxide for Face, Nose & Ears
Source: Environmental Working Group, Bensalem dermatologist Dr. Wayne Marley, Lower Makefield dermatologist Rick Fried
