by Lars Hundley
Recently, two of our regular excellent Road Bike Rider commenters made claims on an article we ran about wearing sunscreen. They both pointed out that neither of them had ever been sunburned through a jersey over multiple decades of cycling, nor had anyone else they know been sunburned that way either.
These two comments made me think back to my own experiences of cycling since the late 1980s. I have also never been sunburned through a jersey, nor through any other item of clothing I’ve ever worn. In fact, during the years where I spent a lot of time riding in the afternoons, I typically had extreme cycling tan lines where my arms and legs and neck would be very tan, but my upper legs under the cycling shorts and my chest, back and tops of my arms covered by my jersey would always be completely fishbelly white, with no tan at all. I have never used any special jerseys that make UV blocking claims.
Similarly, as a chubby young nerd, in the days before I discovered the joys of exercise and cycling, I would insist on always wearing a cotton t-shirt when I went to the beach or the pool, because I was afraid that someone would make fun of me with my shirt off. (As if someone wouldn’t notice I was chubby because of the t-shirt, but never mind that detail.) Even after long days at the pool or the beach in a wet shirt, I never tanned or burned through my shirt.
I thought maybe I was missing something, so I searched to see if there were any studies. I found general claims about how some fabrics and weaves are better at blocking sun than others, and how fabrics with dye block more UV than plain white fabric. But these were primarily lab studies, and there were no specific studies I could find that ever showed that any individual had been sunburned through any specific type of clothing.
Meanwhile, I did learn during those searches that many types of sunscreen one might wear under a jersey can be absorbed into your bloodstream!
“In 2021 the European Commission published preliminary opinions on the safety of three organic ultraviolet, or UV, filters, oxybenzone, homosalate and octocrylene. It found that two of them are not safe in the amounts at which they’re currently used. It proposed limiting concentration to 2.2 percent for oxybenzone and 1.4 percent for homosalate.
U.S. sunscreen manufacturers are legally allowed to use these two chemicals at concentrations up to 6 and 15 percent, respectively. Hundreds of sunscreens made in the U.S. use them at concentrations far above the European Commission’s recommendations.
The ingredients oxybenzone, octinoxate, octisalate, octocrylene, homosalate and avobenzone are all systemically absorbed into the body after one use, according to the studies published by the FDA. The agency also found they could be detected on the skin and in the blood weeks after they had last been used.”
https://www.ewg.org/sunscreen/report/the-trouble-with-sunscreen-chemicals/
For at least the past decade, when personally applying sunscreen, I have only used mineral-based varieties, such as zinc oxide, and I strictly limit its application to areas of skin directly exposed to the sun. Most of those mineral types are not generally thought to be absorbed into your bloodstream and instead work as a physical barrier between you and the sun, which gives them the additional advantage that they also are able to block both UVA and UVB rays like clothing does.
In relation to how clothing blocks both UVA and UVB rays, when I looked into UV rated clothing, the information I found was even more irritating and disheartening.
“Though the study argued that regular clothing, specifically wool items, was more effective in blocking UVR than the UPF 50+ sun-protective garments, the research failed to account for confounding factors such as the number of launderings for all clothing items and differences in the weaving patterns of the fabrics.”
Sure, it must be those “confounding factors….” It’s clear that all those regular clothes stop blocking the sun after you wash them a few times. That’s why people you meet in real life are always getting sunburned while they are wearing old clothing. Oh wait. Come to think of it, I guess I’ve never met anyone in my entire life who has told me they were sunburned through their clothing.
The same study also said this:
“Though chemical additives for clothing are intended to serve protective purposes, the chemicals themselves can pose a carcinogenic risk as evidenced by higher cancer rates observed among firefighters.” Followed by, “Though certain chemical additives, i.e., Rit Sun Guard, have been endorsed by The Skin Cancer Foundation as effective in absorbing UVR, the chemical make-up of such additives remains unknown and further research is needed to confirm that these products do not pose unforeseen health risks.”
My takeaway is that for me personally, I am convinced anything other than a see through mesh jersey is going to block the sun just fine. I’m not going to bother buying UV rated clothing, nor with putting on sunscreen underneath any item of clothing. There’s no compelling evidence to me that UV rated clothing blocks better than regular clothing, and there is evidence that it can be worse at blocking the sun than regular clothes, which was conveniently never studied further and I’m sure never will be.
Readers, I encourage you to challenge my arguments in the comments. If wearing my regular jersey and shorts to block the sun is dangerous and I need to be wearing sunscreen under my clothing and UV rated clothing instead of regular jerseys, please let me know so I can examine the evidence again and change my mind.
Update: After I published, I remembered that my friend Rex Bledsoe owns a company called Aqua Design that sells UPF rated outdoor wear. I emailed him expressing my skepticism, and he had an informative response. (He also has a entire page on his site explaining exactly how his clothing provides a UV barrier.)
Here’s what he said:
“From what I’ve learned from the journey of textiles, there are thousands of combinations that all factor in when UV testing. Material, weaving/knitting technique, weight, and color, all contribute to testing results. Yes, a lot of non-UPF-rated clothes will protect you just like UPF-rated clothes. But how does the consumer make an informed decision unless there is a standard where testing provides a non-biased result?
For most textiles, it’s not a matter of test/fail. It’s about how much UV can penetrate the fabric within a standard measurement of time. A low UPF rating, like 30, would not be as good as 50+ if you were a fishing guide and on the water 8 hours a day. We’ve had several lab tests that were less than 50+. When that happens, we go back to the textile factory and either make changes to the material, construction, or printing process.
The cumulative effect of UV skin exposure, over time, should not be minimized. There is plenty of evidence that skin damage from the sun can occur before a burn is detected. The wise decision is to cover up with lab-certified, UPF clothing, and use/reapply an SPF lotion or spray for exposed areas.”
So I have a couple of Nike jerseys that are highly breathable that I feel effects from the sun after a long arse ride. Not sunburn but my skin temp is above normal and stays that way until the next day.
I am a believer in UV rated base layers.. i have a background in surfing in Rio de Janeiro Brasil and also spent time with my choirs at Schlitterbahn Waterpark north of San Antonio. My first ocean pacific base layer was purchased in their shop. It was rated to 50 UV protection. I have various brands that are rated 50 UV and find that it helps. I ride in South Texas as a roadie. The protection is diminished when you douse your limbs with water, but aometimes due to the intense heat and duration of exposure due to 90 to 100 milers I find that surviving without doising oneself with water causes heart-rate creep to get even more intensified.
Thank you for sharing that information.
I’ve been burnt to a crisp after swimming in the ocean all day with a white cotton t-shirt as sun protection. It’s very painful to remove when there’s sand inside the t-shirt.
That said, I prefer a physical block to sunscreen. I do not put sunscreen on at all. I wear a jersey with base layer, sun protectors on my arms, a buff around my neck and bib shorts.
Some of my arm protectors are UPF rated and most are not. None of the other clothing items I wear are UPF rated.
I am not convinced that it’s worth spending more on a UPF rated piece of clothing and I would definitely never even think about applying sunscreen under clothing. I didn’t even know that was a thing before I read your article.
I definitely do not get tanned in the areas protected by clothing.
Thank you for the feedback about getting burned through a wet cotton shirt. This is useful information that I was not aware of, since I have not personally experienced this or seen it. My argument is weakening with every new comment!
While wet cotton is not a good sunscreen that does not mean that a cycling jersey is a bad sunscreen. Cotton is a poor choice of material for any piece of performance clothing.
Unless it’s a mesh fabric, then IMO any decent cycling jersey should provide sufficient sun protection.
Some newer jerseys appear to have a very thin (but not mesh) fabric. While I have never burned through any of my existing jerseys, I don’t have any of the ultra thin ones (Velocio comes to mind).
I have always assumed that I would need sunscreen under this type of jersey. For that reason and one of attempted vanity, I’ve steered clear.
The anecdotes about never burning through a jersey aside, what’s the evidence say about whether sunscreen under some fabrics is recommended?
UPF ratings are actually time-based, such as so many hours for such and such exposure. So the units are something like hours/watt of exposure. But the measurement worth noting is the reciprocal of that: watts/hour which is a reciprocal of what UPF ratings report. If you plot a reciprocal relationship, you will see a greatly diminished return for increasing UPF rating.
In science, there are many quantities that are time based. To mathematically model these items, you must use the reciprocal so the the time is in the denominator. I have encountered this many times in my career.
Too techie, I know, but this always bothered me about UPF ratings.
Great comment. I looked it up to see exactly what you meant and found a pretty good explanation:
http://www.mpgillusion.com/2012/07/sunscreen-spf-and-diminishing-returns.html
Rit Dye Company sells a product called Sun Guard that treats cotton to attain a 30spf. Sadly it doesn’t work on synthetics. Available online
When I was a kid, my swim team had swimsuits that had blue and black stripes. By the end of the summer, the skin that was covered by the suits had a tan pattern that alternated lighter and darker – I am guessing the black stripes provided the best sun block and the blue somewhat less. Although I didn’t hear of anybody getting “burned” under the lighter area of the suits, more UVs were definitely penetrating through part of the design, so maybe color choice is an important consideration if relying on clothes as a sunblock?
Thanks for that information.
Yes, I have read in some of the articles that color makes a difference and that darker colors block more than lighter colors. I always would have imagined that the lighter colors were reflecting more of it away since they feel cooler to wear than dark colors, but the studies seem to indicate that the darker colors block better. So that’s an interesting anecdote where you could see the difference!
Actually I think applying the SPF is pretty easy ie How many hours will you have significant sun exposure? Perhaps 6 is a reasonable max esp if you stop for while in shade but assume 10 hours=600mins. Assume 20 minutes exposure is healthy/required for Vit D etc. 20 is 3% of 600. Your exposure is reduced to 3% by SPF 30.
Most coloured fabrics have SPF/UPF near or more than 30. Maybe if you have super-thin fabric, or stretch it super-thin or get wet, you could get some sun damage. Bottom-line the numbers align with the poll number that only 1% of riders have managed to find some scenario when they think they have been sunburned thru clothing. Other advantages of gloves, hat under helmet etc in summer are fall protection and physiological heat adaption with the option to take them off during later pm heat peak.
Covering up and using mineral based sunblock on the small exposed areas makes sense. Those crazy spf chemicals just can’t be good for anybody or the environment either.
This article, with quotations, proves that any position can be supported on the internet. Having grown up when all we had was “sun tan lotion” and SPF sunscreen was unheard of, I received more than my share of UV radiation and I am living with skin cancer because of it. My board certified dermatologist says any sun exposure is damaging because it is the cumulative effect that is damaging. I do hope your friend Rex Bledsoe changed your practices.
Thanks for your comment.
I acknowledge and recognize that UV radiation directly on your skin can cause skin cancer. I either cover up or wear a mineral based sunscreen when I am going to be out in the sun for any period of time and avoid sunburn at all costs. My only point was that I believe that you can get very good sun protection from regular jersey fabric, so I don’t believe it is necessary for me to personally wear UPF rated clothing (as opposed to a regular jersey or shirt) or wear sunscreen under my regular jersey.
I’m sorry to hear about your diagnosis. I appreciate you sharing your experience and what your doctor said, which will be helpful to others who do not think that sun protection is necessary — because preventing sunburn and avoiding UV radiation is definitely important.