Max Factor: UV Protective Fabrics
By Tony Jones

The best way to develop skin cancer is to spend as much time as possible in the outdoors without using any sunblock protection. This method certainly isn't fool proof, but the odds are certainly in your favor. Of course, anyone willing to heighten the stakes by going au naturel may as well step to the front of the line and pencil his name in to collect a free dose of melanoma, basal cell carcinoma or squamos cell carcinoma. As statistics show, there is plenty to go around.

Dermatologists estimate that 1 million Americans develop skin cancer every year, but many more are eligible. If you don't get it this year, your chances may actually increase next year. If sheer sun exposure isn't doing the trick, you might also try changing your diet (more fat with fewer fruits, vegetables and grains) and geography (think altitude or equator).

If you're thinking nobody wants to actually get skin cancer, then why is it that the most preventable form of cancer is also the most prevalent?

A survey conducted in 1994 by the American Academy of Dermatology indicates that only two out of every five people consistently use sunscreen whenever they are in the sun. While some may attribute this to a lack of education, laziness and low fatalities may also play roles. After all, more than 90 percent of skin cancer cases are completely cured, so where's the danger? For some, the thought of battling skin cancer must equate with getting rid of the flu. The risk or inconvenience is secondary to obtaining that "healthy" bronze glow--never mind if that glow is the result of radiation.

Let's examine the 40 percent who say they actually apply sunscreen on a regular basis. What percentage use a sunblock with a sun protective factor of 15 or higher? What percentage reapply lotion every two hours?

Here's another: How many people only apply sunblock to areas of their bodies that they know will receive direct exposure to the sun? For a summer hiker, that would be the head, neck, arms and legs. Think about that for a moment. When was the last time you put lotion on your torso or legs, if you knew you would be wearing a shirt or long pants the entire time you planned to be in the sun?

OK. For the 1 or 2 percent of you who have actually done this, did you reapply?

The fact is the vast majority of us consciously or unwittingly treat our clothing as if it were armor against ultraviolet radiation. Our Ph.D.-toting friends in the scientific community, however, say this practice could be a grievous error, unless your clothing is capable of blocking at least 93 percent of the sun's UVA and UVB rays. Unless you always hike or rock climb in black denim or leather, chances are you have repeatedly exposed your skin to ultraviolet radiation without realizing or noticing any immediate effects.

The Shirt Off Your Back

A typical, tightly woven cotton T-shirt, absorbs 84.6 percent of solar radiation when dry and substantially less when wet, according to scientific measurements. To place that figure in terms most of us are familiar with, 84.6 percent is equivalent to applying a permanent lotion with an SPF of about 6.5. In a 1994 study on UV effects through fabrics, hairless mice were irradiated using a solar simulator. The mice protected by the cotton fabric progressed from mild erythema (sunburn) to tumor formation at close to the same rate as the mice which received no protection. Conversely, mice protected by Solumbra I fabric, which was measured at SPF 30+ (about 97 percent protection), showed no signs of sunburn or tumor formation during the same period.

A fabric's ability to shield skin from UV radiation depends on several factors, including the construction (knit or woven), color, mass, fiber count and whether or not it's wet or dry. With all things equal, some studies have shown that untreated, 100 percent polyester fabric provides two to three times more protection than other untreated fibers.

Color seems to play a significant role in the absorption of UV. According to a paper titled Dressing for the Summer Sun by Keith Heidorn, black was found to provide more than five times the amount of protection than white in both 100 percent cotton and 65/35 polyester/cotton blends. Another interesting note reported that denim blue jeans were rated at SPF 100, but undyed white denim measured only SPF 17.

Heidorn also reported that double layers of fabric provide at least twice the protection of single layers; knit fabrics tend to have a higher SPF value than wovens; nylon/spandex knits provide high SPF ratings in all colors; and several bathing suits tested transmitted at least one-third more UV when wet than when dry.

Chair Today, Golf Tomorrow

The photo above shows a Quest tent, on the left, constructed from Jinwoong's UV-Tex 5 fabric after one month of exposure. At right is another tent made from standard industry nylon during the same period. If UV can do this to nylon, what's it doing to your skin?

On the bright side, several fabrics and fabric treatments have surfaced during the last several years which appear to provide substantial protection from both UVA and UVB rays. Inspired by processes that previously protected fabrics against the elements for use in lawn furniture and awnings, UV protective fabrics have filtered into the outdoor industry as tent fabrics, fabric for personal flotation devices and now apparel and accessories. In fact, whether aimed at protecting the integrity of a fabric to extend the life of a tent or designed to protect wearers from harmful solar radiation, UV protective fabrics could become a hot new performance category or technical feature of outdoor products.

"We deal a lot with sun protection in our business and there is a big wave coming up," predicts Robbin Lacy, owner of Sunday Afternoons which manufactures sun protective headwear featuring SolarWeave. "We're just at the beginning of a skin cancer epidemic. I did a fishing show, and I had at least 100 guys over five days show me their skin cancer. These old timers have been out on the ocean for years, and they're finally giving up their ball caps."

"I think [these fabrics] are dynamite and a lot of people are jumping on the bandwagon," says Christina Stoever, marketing manager for Sportif USA. "In two years, if a shirt or short doesn't have protection people are going to wonder why. I think it's a wave. It's like Gore-Tex or waterproofing. For a couple of years it will be really hot because it's new, and after that, everyone will just come to expect it."

Sportif began experimenting with UV protection in some of its technical hiking and angling garments in 1996, using a fabric called SolarWeave from The Solar Protective Factory that blocks up to 98 percent of UVA and 99 percent of UVB. Sportif recently announced that it has expanded its commitment to protective fabrics beginning with its 2000 line, which will incorporate solar protection in all of the company's Supplex nylon clothing as well as other performance fibers like CoolMax.

Sportif will continue to work with The Solar Protective Factory's SolarWeave and SolarKnit and will add Burlington PerformanceWear's M.C.S. Blocker fabric.

"We found that Supplex nylon was a good product because it inherently blocked pretty well, compared to most," comments Terry Breese, president of The Solar Protective Factory, explaining the attributes of SolarWeave. "The trick was to get something lightweight and breathable but that blocked [UV]."

Breese says a light-colored Supplex fabric offers UV protection of about 85-89 percent (SPF 7-9), depending on the weave. By using sanding and other techniques, Supplex's UV protecting abilities can be boosted into a percentage in the low 90s. SolarWeave undergoes a chemical enhancement that boosts a light-colored Supplex to 97 percent protection (SPF 33) and dark colors to 99 percent (SPF 100).

"The chemical enhancement is in the same family of chemicals that are used in everybody else's Supplex because it's really part of the dyeing process," Breese continues. "When you're doing the dyeing, you just add this chemical to the dye. It bonds with the fiber at the molecular level so they are at one. When UV hits the fabric, some of it is reflected, depending on the color, and some of it is absorbed.

"UV gets absorbed into the fibers and then is transmitted across the fiber into infrared and is released externally as heat."

Besides Burlington, there are several companies that offer UV protective fabrics with which outdoor manufacturers and retailers are already familiar. AlliedSignal offers Eclipse nylon designed for flotation devices, tents, surf apparel and boat accessories. Milliken makes a couple of different fabrics, including Solarveil, a sheer fabric designed for beachwear applications that offers 92-95 percent protection when used as a double layer. DuPont's SolarMax is currently being used to improve the durability and colorfastness of tent fabric by Bibler and Moss Tents, as well as in PFDs by Stearns. And Sterling Fibers' acrylic WeatherBloc is beginning to make the transition from outdoor furniture to apparel.

"With the WeatherBloc fiber, the protection is actually built into the fiber so that if you have a construction that does not allow a lot of sunlight through the fabric, then you can get an excellent rating and decent protection," says Barbara Montz, director of marketing for Sterling. "Part of it is that a pigmented fiber or solution-dyed acrylic, in general, has color all the way through. That's where you get your colorfastness."

Montz says apparel featuring WeatherBloc could be available as early as next year and that test fabrics have shown SPF ratings greater than 50 while dry and actually increasing to SPF ratings greater than 70 when wet. Such an unusual feature could have beachwear applications for covering wet bathing suits, as well as possible uses for canoeists and whitewater rafters.

The 'S' Word

With all the activity surrounding UV protective fabrics, the push toward the standardization of testing and claims was inevitable. Protecting the integrity of yarns and boosting the colorfastness of a chair or tent fabric is one thing, but when apparel is being purchased by consumers because of an implied health benefit, you can bet the government is going to get involved.

Many would like to use Australia and Great Britain, which use an ultraviolet protection factor (UPF) rating, as a model or simply provide SPF ratings on the label. But Breese and others say those rating systems can be misleading and don't tell consumers exactly what benefits they are purchasing.

"If you say something has an SPF of 10, what does that mean?" Breese asks. "That means you can be in the sun 10 times longer before you start to redden. That's not true with fabric. SPF was developed for sunscreen lotion, which is slowly evaporating away. It has nothing to do with apparel. Apparel doesn't evaporate or rub off in the water. Its characteristics take years and years before they deteriorate. An SPF of 10 or 30 is meaningless for fabric."

The Sun Protective Factory has chaired the American Society for Testing and Materials subcommittee that is working with the Consumer Products Safety Commission and Federal Trade Commission to establish industry-wide standards. After four years of meetings, Breese says standards have been voted on and he expects some finalization by the end of the year. The rating system that most likely will be employed is a UV percentage.

Thus, a garment with a UV 97 rating would tell consumers that fabric blocks up to 97 percent of ultraviolet light. A label or hang tag may have to specify percentages for both UVA and UVB rays, since fabrics do not necessarily block or absorb the same percentage for both wave lengths. UVB rays are most commonly associated with sunburn and short-term effects, while UVA rays are mostly associated with immediate tanning, deeper penetration and long-term effects.

"The way the standards are going to be positioned--and the FTC is guiding us this way--is there will be a UV percentage that is deemed to be good and a UV percentage that is deemed to be very good," Breese explains. "All the rest won't be able to call something a UV protective garment if they're only protecting 82 percent. You won't be able to claim it's UV protective unless it is substantially protecting people.

"There is going to be a demarcation point," he continues, "and my guess is it's going to be 93 percent. So people will have to get at least that to make any claims at all."

Breese says testing protocol will likely call for a certain number of launderings, probably 40, and exposure hours to UV light, probably 100, simulated by using a photospectrometer.

One advantage of using a UV percentage instead of an SPF rating is that the percentage of UV protection doesn't change with conditions, such as altitude or geography. A fabric that offers 98 percent protection does so whether that shirt is at sea level or 8,000 feet, in North America or Australia. With sunblock lotions, wearers have to consider their own physiology and location when it comes to choosing sunblock protection and knowing how often they should reapply.

"The FTC is forcing this because there are so many claims being made out there," Breese asserts. "There are people who are saying it prevents skin cancer. How can you say that? How do you know that?

"It's a little bit like the Wild West right now. You can sort of say what you want as long as you've got your guns blazing."

Tony Jones is the Managing Editor of Outfitter Magazine