How Harmful Are UV Rays?

How Harmful Are UV Rays? Sun Over Hills

Our skin’s number one enemy is UV (ultraviolet) radiation, but just how bad is it? Like most things, there are a lot of misconceptions and it really depends on the amount of exposure, but it’s proven to cause cancer and definitely something you should be protecting yourself from. Thankfully, most UV shirts for men and women do exactly that – keep you protected.

How & When Are People Exposed to UV Radiation?

The Sun and UV Damage

Women Tanning UV Exposure

The main source of UV radiation is the sun – something we are exposed to just about every day. UV radiation from sun exposure does not penetrate past the skin, but can be extremely damaging and cause cancers which then permeate through the body. Look for products with a high SPF or UPF rating to determine the amount of UV protection a sunscreen or fabric provides.

The sun emits three types of UV radiation, but only two of them even reach our skin:

  • UVA: long wave ultraviolet waves. These do not cause sunburn, but are shown to damage the DNA of skin cells overtime and can lead to skin cancers overtime. Only broad spectrum sunscreens protect you from UVA rays in addition to UVB rays, but UV shirts for men and women with a high UPF rating always protect you from both.
  • UVB: short wave ultraviolet waves. These have more energy than UVA rays and damage the outer surface of your skin directly and are the reason you get a sunburn. Also, UVB rays are thought to be the leading cause of most skin cancers such as melanoma, basal and squamous cell skin cancer. 
  • UVC: The highest energy waves the sun emits, but these never reach our skin thanks to the interaction with our atmosphere. However, this is sometimes emitted through various man-made objects.

Tanning Beds and UV Exposure

The next most common exposure to UV is through tanning beds. While the amount of exposure depends on the duration and the specific lamp used, exposing yourself to unnecessary UV radiation should be avoided.


  • Black-light lamps
  • Mercury-vapor lamps (but these generally only have dangerous UV rays when broken)

UV Studies and Statistics Related

Skin Cancer and UV Exposure in the United States

Building representing US Skin Cancer Facts
  • 9,500 people in the US are diagnosed with skin cancer every day
  • More than 2 people die of skin cancer every hour
  • 90% of non-melanoma skin cancers are associated with UV exposure from the sun
  • The annual cost of treating skin cancer in the US is $8.1 Billion
  • 3.3 million people in the United States need skin cancer treatment annually

Link Between UV Exposure and Cancer in Men & Women

Certain organizations study and post the findings of the different causes of cancer. The International Agency for Research on Cancer (IARC) and National Toxicology Program (NTP) are a couple of them. Below are a few of the many UV related causes that the IARC and NTP have linked to cancer:

  • Solar Radiation
  • Use of UV-emitting tanning devices and exposure to sunlamps/sunbeds
  • Broad-Spectrum UV radiation (including UVA, UVB, and UVC)

Summary of UV Exposure for Men & Women

UV exposure is not something you should take lightly. You should always keep your skin protected with either sunscreen or proper sun protective apparel if you are spending time outdoors.

You should schedule an appointment with your dermatologist immediately if you are concerned about your UV exposure and worried you might have developed skin cancer or have any concerning spots. The included video has a quick summary for things to look for if you are worried at all. Here at Rayward Apparel we are passionate about skin protection, but we are not skin cancer professionals and cannot give medical advice. If you have any questions or concerns about your health, it’s always best to consult with a doctor. 

Protection with UV Shirts for Men & Women

We are committed to helping the battle with skin cancer. We make UV shirts for men and women, all of which have the highest possible UV protection rating – UPF 50+. Also, we donate 5% of all company profits to non profit organizations with a similar mission.

Source: American Cancer Society

Can UV Go Through Clothes?

UV Shirts Exposure, Sunlight over field

So can UV go through clothes? In most cases – yes. But it’s not necessarily if UV can pass through that you should be asking, but how much UV can pass through.

UV radiation is the leading cause of most skin cancers, so it’s important to protect yourself. However, UV exposure is tricky because it’s not possible to see with the naked eye. Just because visible light is not passing through an object or fabric, that does not necessarily UV light is being stopped. And the opposite is true as well – UV protection shirts might be lightweight and seemingly thin – allowing light to pass through, but this doesn’t necessarily mean they allow UV radiation to pass through as well. A great example of this is sunglasses that block 100% of UV radiation. You can clearly see through them, yet UV radiation cannot pass through at all. 

The video to the right shows what the world looks like through a UV camera, or in UV light instead of visible light. It’s an interesting way to show how seemingly invisible factors impact the amount of UV light that can penetrate something. Around the 1:34 minute mark of the video they show a pair of glasses in both visible light and UV light side by side – a great way to see the imperceptible differences. A similar concept applies to fabrics – just because you can’t see through a fabric does not necessarily mean UV radiation is not passing through.

So how are you supposed to know how much UV radiation is penetrating your clothing? And if you have a UV protection shirt, how much protection is that providing?

UPF Rating for UV Protection

The only way to know the true protective value of a fabric is if it has a UPF value listed. UPF stands for Ultraviolet Protection Factor and is a rating very similar to the SPF ratings you’ll see on sunscreen, but is applicable only to fabrics (click here for a full explanation of UPF and how it differs from SPF). 

To list a UPF rating a product must first be lab tested according to industry standards which will show the exact amount of UV radiation which can penetrate that fabric. A rating of UPF 30 means 1/30th, or about 3.33% of UV light passes through. And UV protection shirts with a rating of UPF 50 means 1/50th, or about 2% of UV light passes through. The standard categories you may see listed are below:

UPF RatingProtection Category% UV Radiation Blocked
UPF 15 – 24Good93.3 – 95.9
UPF 25 – 39Very Good96.0 – 97.4
UPF 40 – 50+Excellent97.5 – 98+

At Rayward Apparel we believe all sun protective products should have a rating of at least 50+ providing you the highest level of protection possible. Click here to see our full line of products.

Hooded UPF 50 Bamboo Blue Shirt Rayward Apparel
Mens SUN BOUND Hooded UPF 50+ Shirt

Fit and Fabric

If a shirt is specifically designed with skin protection in mind, it likely has a UPF rating listed. However, the vast majority of products you’ll find will not have anything rating listed – so how are you supposed to know how much UV light is passing through? While it’s impossible to say an exact amount, there are certain factors you can look for which can help in making a determination. This article summarizes which fabrics block UV rays, but if you look for some of the below features you’ll be off to a good start:

  • Materials: Synthetic fibers such as nylon and polyester often perform better than bleached cotton shirts. Also many UV protection shirts are made of bamboo viscose, which is shown to be more absorbent than a standard cotton.
  • Construction: The tighter the weave the better.
  • Fit: Loose fitting is generally better than tight fitting as it’s not going to be stretched out
  • Style: The more coverage the better. Choose long sleeves over short sleeves.
  • Color: Generally the darker the better, but it’s not always the case.

The best way to make sure you stay protected is to buy shirts that have been designed to keep you that way – protected. UV radiation can damage your skin even through clothes, so make sure to keep that in mind whenever you are out in the sun.

What Fabrics Block UV Rays?

What fabrics block UV? Rayward Apparel

Your clothing is more than just a fashion statement, it helps keep you protected from damaging UV radiation – one of the leading causes of skin cancer. Certain types of materials, like bamboo shirts, often come with a higher UPF rating (less UV rays can pass through), but it depends on a lot more factors than just fabric composition. Every product is different, some provide superior protection while others provide little to none. If you are shopping for sun protective clothing and do not see a UPF value listed, keeping the below factors in mind will help make sure you are selecting a product that will help keep you protected.

Fabric Spools


  • Fibers: The fibers themselves have different UV protection qualities. Synthetic fibers such as nylon and polyester generally have a higher UPF value than other popular fibers such as bleached cotton. Bamboo fibers (when purchasing bamboo shirts it’s generally labeled as bamboo from viscose) also tend to have a higher UPF value than cotton. However, the process of turning bamboo into bamboo viscose can sometimes alter the properties of the fabric, so make sure to check for a UPF rating whenever possible and not make any assumptions.
  • Construction: Ultimately the goal is to reduce the amount of light that can pass through. With a tight weave, you have less space between the threads and thus less potential for UV radiation to pass through. Also, a shirt’s thickness can also help protect your skin as it often has more fibers per square inch and much tighter weave. A good simple test is to hold a shirt up to the light – if a lot of light is passing through it likely has a lower UPF rating than a shirt where no light passes through.


Generally speaking, loose-fitting apparel is preferable to tight clothing. Tight clothing has a tendency to stretch which separates the fibers – allowing more light to pass through. Loose unstretched fibers are going to provide more consistent protection, and also less likely to become permanently stretched overtime and maintain its protection rating for longer. For more information on the longevity of sun protective shirts click here.


The more coverage the better. It goes without saying that a short sleeve shirt cannot keep your entire arm protected, so try and find products that maximize the surface area coverage. Long sleeve bamboo shirts are great, and hooded long sleeve shirts can take that a step further in helping to keep your neck protected as well.

Fabric Colors Bamboo Shirts


Darker is better, but there is no formula for determining which specific color is best for sun protection. If you have to choose between a black and white shirt and are looking for maximum UPF value, more often than not the black shirt will provide more protection. This is in part due to the color absorption properties, but also due to the process of coloring a fabric with different dyes which further reduce the amount of UV radiation that can pass through. But keep in mind – just because a shirt is white does not mean it is not keeping you protected. A shirts protective qualities is a combination of all of the above factors and it’s very possible that your white bamboo shirts are keeping you just as protected, if not more protected than your black cotton shirts. 

UPF Rating

The safest way to make sure you are protected is to buy products with a posted UPF rating. This means that the shirt has been tested and proven to have UV protective qualities. For maximum protection, look for apparel that has a UPF 50+ rating.

Sun Protection Myths: Know the Facts to Prevent UV Damage

Beach Lounging with Umbrella

There are many myths, misconceptions and misunderstandings when it comes to sun protection and preventing sunburn. At Rayward Apparel, however, our goal isn’t just to provide sun protective clothing, but also to provide the information and resources necessary to make you sun smart and UV protected.

Continue below as we bust some of the most damaging sun protection myths:

Sun Protection Myths vs Facts:

MYTH“All sunscreens protect against harmful UV damage.”
FACT: In reality, only “broad spectrum” sunscreen adequately blocks both UVA and UVB rays from the sun. UPF clothing, on the other hand, always blocks both types of UV rays. Therefore, you can trust UPF apparel.

Beach Sun Protection Facts vs Fiction

MYTH“You can’t get sunburn on a cloudy day.”
FACT: Clouds may filter some UV rays, but they do not block skin damaging UVA rays. Therefore, even in cloudy, overcast or foggy weather, sun protection clothing is paramount.

MYTH“You can’t get sunburn in the winter.”
FACT: UV damage doesn’t go on holiday. In fact, while UVB rays are strongest during the spring and summer, you are still being bombarded with UVA rays throughout the year. Furthermore, if the ground is covered by reflective snow or ice, you could actually be hit twice.

MYTH“Glass windows protect you from UV rays.”
FACT: Glass may filter out UVB rays, but UVA rays penetrate most glass surfaces. As a result, unless you are certain a glass window has been treated to block UV rays, wear sun protection apparel even behind glass (such as on a plane, bus, train or car).

MYTH“UV rays don’t penetrate the water’s surface and are blocked.”
FACT: Not only do the sun’s UV rays penetrate beneath the surface of water, but they also reflect off of it. They therefore cause damage both above and below the water’s surface.

Water Reflects UV Rays at the Beach

More UV Protection Myths vs Facts:

MYTH“Hair offers adequate UV protection.”
FACT: In fact, even a thick head of hair or a full beard don’t provide sufficient UV protection. Therefore, they should be protected with broad spectrum sunscreen and sun protection apparel.

MYTH“Regular clothing protects you from the sun.”
FACT: It’s safest to only trust clothing clearly labeled with a UPF rating, but the higher the better. In fact, certain fabrics, such as plain cotton, offer a false sense of security with little in the way of actual UV protection. As a result, anything without a UPF rating should be avoided.

MYTH“Lighter colored clothing, such as yellow, offers better sun protection.”
FACT: All else equal, darker colors (such as black, blue or red) absorb more UV rays, and therefore typically protect better than lighter colors like white or yellow.

MYTH“Beach umbrellas offer adequate UV protection.”
FACT: In fact, umbrellas only block direct UV rays from above. Meanwhile, they do little to shield you from indirect UV rays bouncing or reflecting off other surfaces, such as water or sand.

Beach Lounging with Umbrella

Final Sun Safety Myths vs Facts:

MYTH“It’s ok to get sunburn every now and then.”
FACT: Sun damage is cumulative. That is to say, every additional exposure leads to a greater risk of melanoma and skin cancer. Therefore, each case of sunburn is increasingly unhealthy.

MYTH“Unless you get sunburn, then you’re not damaging your skin.”
FACT: In reality, the sun’s UVA rays are already damaging your skin well before any indications of sunburn.

MYTH“It is safe to sun tan in short intervals. For example, just to get a ‘base.'”
FACT: Firstly, there is no such thing as a healthy tan. In fact, UVA rays, the ones which cause skin tanning, directly contribute to the development of skin cancer.

MYTH“Tanning and sunbathing help prevent skin cancer in the future.”
FACT: The tanning effect is your skin’s direct response to being damaged by UVA rays, and does not prevent skin cancer.

Now that you’re informed, it’s time to get protected, and that’s where Rayward Apparel really shines with our exclusive focus on UPF 50+ apparel. We specialize in UV protection shirts that are as protective as they are comfortable, so shop Rayward Apparel today!

Source: Skin Cancer Foundation,

What is the Difference Between UPF and SPF?

Kayaking at Sunset with UPF Protection

You’re probably familiar with the SPF (sun protection factor) ratings found on sunscreen, but what is UPF clothing? Did you know clothing has its own UV protection rating system? You’ll see this rating, known as an ultraviolet protection factor, or UPF for short, when buying sun protective clothing or bamboo apparel. But what exactly do SPF and UPF ratings measure, and how do they compare?

Before we dive into the differences, it’s important to understand the reason we are protecting our skin at all. The ultraviolet (UV) rays from the sun are harmful, especially during long periods of exposure. Unprotected exposure to UV rays damages the skin, and cause over 90% of all nonmelanoma skin cancers.

Sunny blue sky with UV rays


Sunscreen labeled as “broad-spectrum” blocks both UVA (long wave ultraviolet A) and UVB (short wave ultraviolet B), each of which damages the skin. Any sunscreen not labeled broad-spectrum is generally designed simply to protect from short wave UVB rays to avoid a burn, but will not block harmful UVA rays. Whenever possible, always choose broad-spectrum protection.


SPF stands for “sun protection factor” and is a relative measure of a sunscreen’s effectiveness in protecting your skin from UV rays. A higher SPF rating means that it will block a higher percentage of UV rays, but nothing is 100%. The number generally correlates to the multiple of time in which you can avoid a burn. So if you would normally burn in 10 minutes, and properly applied an SPF 30 sunscreen, it would take you about 300 (10 x 30) minutes to burn (assuming you are constantly covered and re-applying).


So we know what Broad-Spectrum and SPF are, but what is UPF clothing? UPF (ultraviolet protection factor), on the other hand, is specific to sun protective fabrics. UV radiation can penetrate clothing and as with SPF, the higher the value, the more protection you receive. The specific UPF rating of the garment indicates the amount of the sun’s UV radiation it allows through. For example, a UPF 50 shirt only allows 1/50th or 2% of the UV rays through, a UPF 30 shirt only allows 1/30th or about 3% through, and so on. Plus, unlike sunscreen, UPF apparel always blocks both UVA and UVB rays and is always broad-spectrum.

UPF ratings can be difficult to identify, as they’re rarely marked in any product details. That is, unless the garment is specifically designed for UV protection. The average cotton t-shirt’s UPF value is 5 or less, and determining the exact UPF rating requires costly, time-consuming testing. Also, while it’s required that apparel show its country of origin and fabric content, there is no requirement for a manufacturer to provide the product’s UPF rating. This leads to many companies taking the cheap and easy route—not listing it at all. So in general, if an article of clothing does not have a UPF value listed (and it’s not thick like denim or heavy fleece), it’s safest to assume it does not provide significant UV protection.

Kayaking at Sunset with UPF Protection

SPF & UPF, In Summary:

  • SPF rates the UV protection effectiveness of sunscreens
  • UPF rates the UV protection effectiveness of protective fabrics
  • UPF is always broad-spectrum, SPF is not
  • Fabrics with UPF provide constant coverage, SPF and sunscreens need regular re-application to maintain protection
  • When choosing UPF apparel, look for ratings of UPF 50+ for the best protection

Rayward Apparel focuses exclusively on UPF 50+ apparel, specializing in sun protective shirts that are as comfortable as they are protective. Shop Rayward Apparel today!

Our vision sees through the sun’s glare and extends far beyond clothing. We go beyond clothing with our dedication to supporting the fight against skin cancer, donating 5% of all profits to charities with a similar vision to ours. Click here to learn more about how we give back.

Source: Skin Cancer


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