Most sun protective garments rely on the fabric’s natural ability to block UVR. Sun protective garments are not usually specially treated, although chemical treatments are available. Laboratory testing determines how effective a material is at blocking UVR and this is often stated on the garment label as a UPF rating. The UPF rating of a material can be determined by placing it under a UVR lamp and measuring the amount of UVR that passes through the fabric. From this UVR transmission data the UPF rating can be calculated.

The UPF rating indicates how much the material reduces UVR exposure. For example, a material with a UPF rating of 20 would only allow 1/20th of the hazardous UVR falling on its surface to pass through it. A garment made from this material would reduce UVR exposure on the areas of skin it covered by a factor of 20.  All UVETO products have a 50+ UPF rating.

The UVR protection offered by different types of fabrics varies considerably and depends on the factors listed below.

What makes a good sun protective garment?

Several factors determine how effective garments are at reducing UVR:

• Composition of the fabric: Different materials such as cotton, polyester and nylon have different natural UVR-absorbing properties.
• Weave density: Less UVR passes through tightly woven or knitted fabrics. As shown below the smaller the spacing between the individual fibre strands the higher the protection.

• Colour: Many dyes absorb UVR. In darker colours of the same fabric type (black, navy, dark red) will absorb UVR more strongly than light pastel shades (white, sky blue, light green) and consequently will have a higher UPF rating.
• Tension: Stretching a fabric may cause a decrease in the UPF rating. This is common in knitted or elasticised fabrics and care should be taken to select the correct size for the wearer.
• Weight: Heavier weight materials generally have a higher UPF ratings than lighter materials of the same type.
• Moisture content: Many fabrics have lower UPF ratings when wet. The drop in UPF rating depends on the type of fabric and the amount of moisture it absorbs when wet.
• Design: As well as considerations of fashion and comfort, selecting garments that are sensibly designed for sun protection can make a large difference to your overall UVR exposure. A shirt with long sleeves and a high collar offers more protection than a short-sleeve shirt without a collar. Loose fitting garments give better protection than garments that are worn close to the skin and also may be more comfortable to wear on hot days. A legionnaire style cap with a flap protects the ears and back of the neck. A broad-brimmed hat shades the face and neck.
• Condition: Unless otherwise stated, UPF ratings are made on fabrics that are in new condition. The UPF rating of many cotton based fabrics can improve over the “new” rating after they have been washed at least once. Shrinkage in these fabrics closes small gaps between the fibres and allows less UVR to pass through. However, old, threadbare or faded garments may have a lower UPF rating.
• UVR absorbers: Some fabrics are treated to improve the UPF rating. This is usually done if the base fabric has a low natural resistance to UVR. Treatment with a UVR absorber, generally during manufacture, can result in a fabric with a higher UPF rating that still retains the comfort properties of the original fabric. Many dyes absorb UVR and therefore increase the UPF rating of the fabric. Some UVR absorbers behave like colourless dyes. They bond to the fabric in a similar way, and have a comparable permanency to coloured dyes. Recently there has been interest in adding UVR absorbers to commercial washing powders.

Make sure that any sun protective clothing that you order has a UPF rating of 50 plus.

UPF is an abbreviation for Ultraviolet Protection Factor. This rating system is used to measure the effectiveness of fabric to protect skin from harmful ultraviolet radiation. For example, a UPF rating of 40 will allow only 1/40th of the sun’s harmful rays to penetrate the textile. A rating of 40 or higher is considered excellent, blocking 97 percent of both UVA and UVB rays.

SPF, typically associated with sunscreen, is short for Sun Protection Factor. This measurement determines the length of time it takes for redness to occur as result of sun exposure. If applied correctly, a sunscreen rated at SPF 15 will protect 15 times longer than unprotected skin. This amounts to approximately 93 percent of UVB rays. Some experts believe that no sunscreen should be expected to stay effective longer than two hours without reapplication. Sunscreen that blocks UVA and UVB radiation is preferred.

UVA and UVB

Simply stated, UVA exposure contributes to premature aging by damaging the skin’s elasticity. Perhaps 90 percent of wrinkles, age spots, and visible signs of aging occur as result of the sun’s harmful UVA rays which penetrates the skin more deeply. The carcinogenic effects of UVB rays are believed to cause tanning which is the skin’s natural defense against the sun. Unfortunately, it is believed that UVB contributes to the development of skin cancer.

UPF Chart

Products with high SPF rating give a false sense of security resulting in users staying out in the sun longer with a single application and get burned when the products’ chemicals break down, wash off or rub off on clothes and towels. The result is that they absorb more UVA radiation and they get the same number of sunburns as unprotected sunbathers.

As early as 2007, the FDA published draft regulations that would disallow companies from labeling sunscreens with a rating over SPF 50+. The agency feels that anything higher than SPF 50+ would be “inherently misleading” given that “there is no assurance that the specific values themselves are in fact truthful…”

The second key issue with sunscreens these days is two products found in many sunscreens.

The FDA has been investigating a form of vitamin A called retinyl palmitate, found in 41 percent of sunscreens as it is suspected to accelerate skin damage and elevate skin cancer risk when applied to skin exposed to sunlight. The other is oxybenzone, a hormone-disrupting compound found in about 60 percent of the 500 sunscreens analysed. The product enters the bloodstream through the skin barrier. Biomonitoring surveys have detected oxybenzone in the bodies of 97 percent of Americans tested.

So what is recommended in order to stay safe in the sun? Some of these recommendations include selecting and using sunscreen well, as well as other options for sun protection available.

1. Look for minerals zinc or titanium dioxide in the sunscreen.

2. Avoid high SPF. Stay with SPF 15-50+ as suitable for your own skin type. Use SPF 30+ for beach and pool and reapply often.

3. Water-resistant beach, pool and exercise.

4. Apply sun tan lotion early. Martin A. Weinstock, professor of dermatology at Brown University recommends the application of sunscreen half an hour before heading outdoors and reapplying every few hours.

5. Apply in sufficient amounts. Studies show that people apply on average just a quarter of the required amount. Sunscreen efficacy drops rapidly on under-application so it is recommended to observe the instructions on the packaging.

6. Reapply often. Sunscreen chemicals break apart in the sun, wash off and rub off on towels and clothing.

7. Use clothing and hats. One study found that melanoma risk was cut by 52 percent for parts of the body usually covered by clothing during summer outdoor work (Holman et al 1986). EWG believe shirts and hats are the best sunscreen for all. Use UPF50+ rated swimwear and shirts and hats effectively

8. Make shade by putting up an umbrella, locate a picnic spot under the tree, take a canopy to the beach. Infants are best kept in the shade as they lack tanning pigments (melanin) to protect their skin

9. Plan around the shade. Unless you really need to, schedule your outdoor visits to avoid the mid-day sun. UV radiation peaks at midday, when the sun is directly overhead.

10. Sunglasses are essential. These are not just a fashion accessory but are necessary to keep your eyes from the UV radiation, a cause of cataracts.

We hear a lot about climate change and global warming. We’re told that the situation has become very serious. But when it comes to how we can help, the advice seems inadequate. And let’s face it… Most people aren’t willing to make an effort, particularly if it involves sacrifice. Well, it doesn’t have to. Your roof can do the job for you!

That’s what “cool roof” technology offers, effortlessly reducing your cooling energy use by 20-70%. (That’s a number straight from the Environmental Protection Agency). When the sun’s infrared radiation hits a traditional roof, it heats it up, which increases inside temperatures. To cool things down, your air conditioner works harder, driving up your electric bill.

Cool roofs do two things. They reflect incoming radiation back into the atmosphere (reflectance) and help your roof release trapped heat (emittance). This keeps your home cooler and reduces your energy use, but there’s other benefits as well.

Reduced energy use means that power plants don’t have to work as hard, so they produce fewer emissions. Your roof and its insulation last longer thanks to a decrease in temperature extremes and expansion/contraction cycles. This saves you money in the long term and reduces landfill waste. And with lower rooftop temperatures, the surrounding outside air becomes cooler, which helps mitigate the “heat island effect”. This, in turn, reduces smog levels.

THEN WHY AREN’T ALL ROOFS “COOL”?

In part, it’s because of some pervasive myths.

Myth #1: “Cool roofs are only available in white.” Nowadays, you can find cool roofing materials in a wide variety of colors. There’s no getting around the fact that lighter colored roofs will save you more money than dark ones, but if you’re set on having a black roof, a cooler alternative is available.

Myth #2: “Cool roofs only make sense in warm climates.” The assumption is that winter heat losses will outweigh summer benefits. However, in many cold climates, rooftops don’t factor in much when it comes to winter heating. Snow creates a cool roof of its own. Winter days are shorter and tend to have more frequent cloud cover, decreasing infrared radiation. Lastly, the sun is lower in the sky, with rays hitting roofs at an angle rather than from overhead.

In summer, on the other hand, rooftops are a big factor. The sun is directly overhead, skies tend to be clear and days are longer and hotter. Summertime is also the time of “peak demand”, when energy prices in many localities shoot up. While it’s true that the payback time for a cool roof will be longer in cold climates, it still makes energy sense for most buildings that use air conditioning.

Myth #3: “You can get the same benefits from better insulation.” There’s no doubt that good insulation is critical to making a building energy efficient. It should go hand in hand with cool roofs wherever possible. However, insulation alone can’t decrease a building’s exterior temperature, meaning that it won’t reduce the heat island effect. Which brings us to…

WHAT DOES THIS HAVE TO DO WITH GLOBAL WARMING?

In November of 2005, New Science magazine caused a stir when they theorized that the rise in global temperatures might be “cancelled out” if everyone embraced cool roofs. Not only would cool roofs produce an immediate drop in local temperatures, but the resulting reduction in energy use would lower greenhouse gases produced by power plants. Greenhouse gases are what drives global warming.

In April of 2006, Arthur Rosenfeld, a founding father in the field of energy efficiency, published his paper ‘Cool Roofs to Save Money and Delay Global Warming‘. This much more thorough work showed that even a relatively small deployment of cool roofs in major tropical and temperate cities would slow global warming’s progress by one critical year.

Delaying global warming buys us time to reduce our emissions elsewhere. For example, we can create more efficient appliances, generate more of our energy sustainably and reduce vehicle emissions, all of which help counter climate change. (Speaking of cars, light colored vehicles need less air conditioning, which gives them a 2% boost in fuel efficiency.)

IS MY HOME A COOL ROOF CANDIDATE?

Cool roofs save the most money for buildings with one or more of these characteristics:

• Significant air conditioning use in summer
• Little or no insulation
• Ducts running through the attic
• Clear skies most of the summer
• No emissions, such as from chimneys

For more insight, try the DOE Cool Roof Calculator. (If your building has an enclosed attic, read on for more accurate tools.) Also try the Energy Star Roofing Calculator.

According to a review by Nexant, Inc, these calculators tend to underestimate how much money you can save. Instead, they recommend the more comprehensive analysis tools listed at the DOE’s Building Energy Software Tools Directory.

HOW DO I EVALUATE COOL ROOFING PRODUCTS?

As we mentioned earlier, “reflectance” refers to how much incoming solar radiation a material reflects back into the atmosphere. “Emittance” refers to how much heat is released by a material rather than being absorbed.

Reflectance and emittance ratings for cool roofing products generally decrease in the first year of use, then level out. This is primarily due to dirt buildup. To qualify for the Energy Star label, materials for low-slope (relatively flat) roofs must have an initial reflectance of .65 and a 3 year reflectance of .50. Materials for high-slope (steep) roofs must have an initial reflectance of .25 and a 3 year reflectance of .15.

Cool roof incentive programs tend to have stricter requirements. Typically, they look for an initial reflectance of at least .70, and an initial emittance of at least .75.

Roughly 90% of US homes are topped with asphalt shingles, the hottest roofing material available. According to the Lawrence Berkeley National Laboratory, a generic dark brown asphalt shingle has a reflectance of .08, but its “cool” counterpart has a reflectance of .27. That means that even the worst roofing choice should meet Energy Star requirements, so long as a cool version is used.

Here’s how cool roofing materials rank:

• Field-Applied Coating (.92/.87)
• Factory-Applied Coating (.90/.89)
• Single-Ply-Thermoplastic (includes TPO, PVC, etc.) (.88/.87)
• Single-Ply-Thermoset (includes EPDM, Hypalon) (.85/.87)
• Built-up Roofing (incl. asphalt and coal tar pitch) (.80/.90)
• Modified Bitumen (.84/.81, .75/.93)
• Metal (.75/.86)
• Tile or Slate (.76/.84)
• Asphalt shingles or shakes (.27/.92)

There are other types of roofing materials that you may want to consider as well. Sod or “green roofs” are best for roofs that can handle extra weight. They keep infrared radiation from ever reaching the roof. In addition, they also lower the temperature of the outside air, reduce stormwater runoff, sequester carbon dioxide and replace lost green space in urban areas. On flat roofs, they can be rooftop gardens, providing food, beauty, wildlife habitat and a bird’s eye view.

Then there’s solar shingles. These take advantage of incoming solar energy to produce clean electricity. There are also thermal shingles, which heat water more efficiently than a hot water heater.

Both options tend to cost a lot more upfront than cool roofs, but for many, the added benefits are worth it.

Now back to our subject. When it comes to colors engineered to be cool, white is the coolest, but other colors may not rank the way you’d expect:

• White
• Yellow
• Pearlescent
• Red, orange
• Green
• Gray, blue, purple
• Brown, black

The Cool Roof Rating Council was created to provide accurate testing, evaluation and labeling of cool roofing materials. They have a searchable database online, and you can even sort your results.

Of course, there are other important considerations when choosing a roof, such as its…

• Purchase price
• Installation cost
• Reputation
• Weight (Can your building safely support the load?)
• Fire rating
• Ability to protect your building
• Maintenance requirements and costs
• Manufacturer’s warranty, including exclusions and hidden costs
• Durability
• Long-term color retention
• Resistance to dirt accumulation
• Retardance of biological growth
• Coverage under your homeowner’s policy
• Acceptability to your neighbors
• Overall environmental impact, including runoff and recyclability

HOW MUCH WILL IT COST?

Costs vary by material. Some cool products cost the same as their standard counterparts, while others cost more. Some even cost less, since removing an old roof costs more than simply covering or coating it.

Of course, these are only the upfront costs. Remember, most cool roofs last longer than their non-cool counterparts and save more money on electric bills. And if you ever have to replace your air conditioner, you should be able to use a smaller unit, thanks to your reduced energy use. On the other hand, some cool roofs come with extra maintenance costs.

Incentives for cool roofs range from rebates to tax deductions and loans, and come from utility companies, federal, state and local governments. Usually, these are offered through energy efficiency programs, although there are programs specifically for cool roofs. Residential roofing rebates average around .10 cents per square foot, while commercial roofing rebates average around .20 cents per square foot.

Some cities provide home maintenance rebates to help seniors, single parents, low income households and disabled individuals maintain the exterior of their homes. Check to see if yours is one of them.

Once you’ve selected a roof, ask the manufacturer if they provide a better warranty or other incentive if you’ll work with one of their preferred contractors. If not, the National Roofing Contractors Association provides guidance on choosing a installer, plus a toll-free number to call for contractors in your area. Try to find one with hands-on cool roofing experience.

So there you have it… the what, why, how and how much of cool roofs!

When working outdoors, protect yourself from skin cancer in five simple steps.

1. Seek shade: reduce your total sun exposure tally every day by working in the shade, indoors or at times when UV levels are lower – early morning or late afternoon.
2. Slip on sun protective work clothing and gloves.
3. Slap on a sun protective hat.
4. Slide on sunglasses.
5. Slop on SPF 30+ broad spectrum sunscreen.

Everyone is exposed to ultraviolet (UV) radiation from the sun. Many people are exposed to UV radiation from other sources such as solariums, sun lamps and arc welders.

The sun sends out different types of radiation – visible light that we see as sunlight, infrared radiation felt as heat and UV radiation that we can’t see or feel.

People often confuse infrared and UV radiation. When the temperature is cool it means less infrared radiation but not necessarily less UV radiation.

Types of UV radiation

There are three types of UV radiation, categorised by wavelength: UVA, UVB and UVC.

• UVA can cause sunburn, DNA (cell) damage in the skin and skin cancer.
• UVB causes skin damage and skin cancer. Ozone stops most UVB from reaching the earth’s surface.
• UVC is the most dangerous type of UV. Ozone in the atmosphere absorbs all UVC so none reaches the earth’s surface.

When it comes to shielding your skin from UV radiation, not all apparel is created equal. You need to know how to select a UV-safe wardrobe, whether it’s from your closet or from specially made clothing.

So, what’s the difference between a sun-protection shirt and a regular shirt?

All fabrics have some degree of sun protection. When the sun hits the surface of a fabric, the UV radiation breaks down. Some gets reflected, some is converted to heat, and the rest reaches your skin. The difference is that a white, summer-weight (lightweight) cotton tee usually rates at about UPF 5 or 8. That means the shirt lets in about 1/5th or 20% of the harmful UV radiation. A shirt with a UPF 50 rating means the shirt only lets in 1/50th of the ultraviolet (UV) radiation (about 2% of the harmful rays).

Harmful rays? What the heck are those?

There are three types of UV rays: UVA, UVB, and UVC. UVC gets absorbed by atmospheric gases before it reaches earth’s surface, so we don’t have to worry about that type. UVA and UVB don’t get absorbed, and they can cause premature wrinkles, leathery alligator-skin, and skin cancer. Both types of rays penetrate clouds. UVA, however, dives into the skin more deeply than UVB rays, and UVA also slips right through untreated glass. UVA can also impact your skin no matter what time of the day it is (if it’s light out, the UVA is lurking around), whereas UVB rays are most harmful between 10am and 4pm.

What about sunscreen?

Sunscreen is good, and some sunscreens now have UVA and UVB protection, but the current SPF standard doesn’t measure the amount of UVA protection, so it’s hard to know how much UVA the sunscreen really blocks. Also, people don’t always use sunscreen the way it should be used. Not in the sense that they’re eating it or snorting it, but in the sense that they don’t apply it 20 minutes before they go out in the sun (it needs that amount of time to start working), and they don’t reapply throughout the day.  Plus, for people with sun-sensitive skin, sunscreen is not enough.

Some also worry about the chemicals in certain sunscreens (the chemicals used to make a sunscreen waterproof, in particular). And, have you ever tried putting sunscreen on a squirming toddler?

OK, so SPF and UPF … which is the typo?

Neither. Those are two different types of ratings.

SPF (sun protection factor) is a rating system for sunscreen. SPF measures the length of time the sunscreen protects your skin compared to how long it would take your skin to burn without the sunscreen. If it takes 15 minutes for your skin to start to get red, then sunscreen with SPF 15 means you can stay in the sun 15 times as long with the same result (15 x 15 = 225 = 3 and 3/4hrs). Keep in mind the time of day as well (the sun will be stronger mid-day), and the fact that this is only the measurement for UVB protection.

UPF is the measurement used for fabrics. The UPF rating tells how much of the sun’s UVA and UVB radiation comes through the fabric. Both UVA and UVB are measured. Below is the percentage of UVA and B blocked:

UPF 15-24 blocks 93.3-95.8%

UPF 25-39 blocks 96-97.4%

UPF 40-50+ blocks 97.5-98%

Are fabrics treated with something to make them have a UPF rating?

Some are, and some aren’t.

That’s not much of an answer.

You’re right, that was pretty lame.

Some companies use treatments, some don’t. Here are the things that influence how much UV gets through a garment.

1. The density of the weave or knit of the fabric (denser construction = less space between the yarn = less UV).
2. The type of fiber. Lycra and polyester disrupt a lot of UV light, nylon does a good job, and wool and silk are fairly good. Cotton and hemp really don’t block much UV.
3. The specific type of dye. Some dyes use specific molecules that disrupt UV radiation, so the higher the density of those dyes, the darker the garment is, and more UV gets blocked.
4. Chemical treatments. Some companies introduce chemicals (colorless dyes) during fabric-processing, and the dyes become embedded in the material and absorb or disperse UV light.
5. Stretch and wetness also affect the fabric. A ton of stretch and water-logging increase the amount of UV the fabric lets through.

But … isn’t it mostly older people who wear that sun-protection stuff?

Actually, a lot of young surfers wear sun-rated clothing. Younger people are realizing that taking care of their skin will mean having younger-looking skin for longer (not to mention the whole avoiding-skin-cancer thing). It’s sinking in that health is more important than going bronze for a few months in the summer.  Plus many clothes with sun protection look totally casual.

Genevieve Mount

• Each year more skin cancer cases are diagnosed than the combined incidence of lung, prostate, breast and colon cancers.

• Between 40 and 50 percent of Americans who live to age 65 will contract skin cancer at least once.

• An estimated 68,720 cases of melanoma, the most deadly form of skin cancer, were diagnosed in 2009.

• More than 11,500 people die from skin cancers in the United States each year.

• Of the 11,500 deaths from skin cancer, about 8,600 are from melanoma.

• Exposure to tanning beds before the age of 35 increases the risk of melanoma by 75%.

• More than one million people visit tanning salons every day. Of these, approximately 71% are girls and young women aged 16-29.

• People who use tanning beds are 2.5 times more likely to develop squamous cell carcinoma and 1.5 times more likely to develop basal cell carcinoma.

• Young women, under the age of 39, have a higher probability of developing melanoma than any other cancer except breast cancer.

• Ninety percent of pediatric melanoma cases occur in girls aged 10-19.

• Melanoma is the most common for of cancer for adolescents and young adults 15-29 years old.

• When diagnosed early, 99% of melanoma patients survive longer than 5 years.

• Melanoma can be completely cured when diagnosed early.

• Squamous cell carcinoma is the most common skin cancer among African Americans and Asian Indians.

• Most non-melanoma skin cancers are related to sun exposure.