20 April 2021
Sun protective clothing/ UPF- A lot of you may be familiar with the damaging effects of UV rays from the sun; and the importance of using sunscreen; especially if you’ve been following my blog and Instagram. Today’s blogpost will look at how our choice in fashion can provide even more protection against UV rays than sunscreen.
P.S: International Sunscreen Day falls on May 28, 2021; so stay tuned for a series of sunscreen and sun protection related posts on the blog and Instagram (@DrRachelHo) each week this month. Everything from new sunscreen reviews (and new favourites to share), sunscreen scandals and tips on how to apply sunscreen for a better finish will be covered.
Meanwhile, you can catch up with the basics of choosing sunscreens, FAQs and my old sunscreen reviews on the blog.
Although a lot of us are aware of the necessity of using sunscreen, are we using enough sunscreen? According to several studies, the answer is: No; with most of us using only a quarter of the recommended amount of sunscreen1,2! In addition, if you neglect to use sunscreen on the exposed areas of our bodies such as our neck, hands and legs; you’re getting far less UV protection than the SPF and PA values on your sunscreen labels2,3.
One effective and convenient way to overcome these issues of inadequate sun protection is to also use clothing and accessories with high Ultraviolet Protection Factor (UPF). These sun protective clothing are are made up of fabrics that block out a significant portion of UVA and UVB. Personally, using UV protection outfits has been a game changer for me when reapplying sunscreen is impossible (read: two young children who think sunscreen is icky and will not remain still for application).
UV protection outfits and accessories provide additional photoprotection for exposed skin of the body e.g. neck, hands and legs. This is especially useful for some of us who may:
• Neglect/forget to use sunscreen over exposed skin of the body
• Are unable to reapply sunscreen every 3-4 hour or when it comes off (e.g. working out)
Sun protective clothing come in handy to provide consistent protection against UV rays for the body for the duration of the wear. This protection does not wear off every few hours, unlike sunscreen.
I find UV protection outfits very helpful for protecting my children against photodamage, especially sunburns. My son, Sean in particular, gets sunburnt very easily. Children have thinner skin than adults; so they are more vulnerable to the effects of UV rays4. Research shows that getting a sunburn at any point in our lifetime (including childhood) increases the risk of skin cancer5.
Ultraviolet protection factor (UPF) is a measure of a fabric’s protection against both UVA and UVB rays. The higher the UPF value, the better the protection. A clothing with UPF 50 allows 1/50 (2%) of UV rays to reach the skin. You can think of UPF as the clothing as the equivalent of SPF/PA rating for a sunscreen.
The UPF standard was adopted in Australia to measure penetration of UV rays for fabrics.
The UPF value of a fabric is calculated using a mathematical formula that looks at several factors including: transmission of UV rays through the fabric; solar irradiance; and erythema response on human skin6. These parameters are measured in a laboratory, in vitro.
Sun protection factor (SPF) is a measure of a sunscreen’s protection against UVB rays specifically. UPF measures a fabric’s protection against both UVA and UVB rays. UVA rays are the rays that cause signs of premature skin aging (e.g. hyperpigmentation, fine lines and sagging).
Sunscreen which needs to be reapplied every 3-4 hours because its efficacy wears off. For UV protection outfits, the UPF benefits are consistent throughout the duration of wear.
All types of clothing provide some amount of UV protection- the presence of tan lines from clothes are a testament of that. However, most types of clothing do not provide adequate protection. A regular cotton T-shirt has a UPF 77; this is insufficient UV protection, especially if you are outdoors for a long period of time.
In Singapore, the UV index is high all year round. Even if you’re indoors, sun protection remains necessary. Most glass windows block out at least 95% of UVB rays from the sun. However, UVA rays have longer wavelengths and can pass through glass windows. So when you’re indoors or in a car, UVA rays can reach your skin to accelerate signs of aging.
Several factors determine a clothing’s UV protection performance.
Clothing made from nylon, polyester and wool have better UPF8. In particular, the molecular structure of polyester contains benzene rings; which is also present in sunscreen filters like Avobenzone.
Colour of clothing
Coloured/ dyed fabrics have better UV protection than light fabrics. This is because some dyes contain benzene rings and act as UV absorbers6. Dark colours like black, dark blue and dark green have higher UPF than lighter colours9. This would also mean that for a clothing’s colour starts to fade, its UPF also decreases.
Fabric construction and fibre content
In general, the more breathable the fabric (i.e. more holes in the fabric construction); the lower the UPF value7. For example, denim has a UPF of 1700, vis a vis cotton, which has a UPF of 77. This is because more UV rays can pass through the fabric to reach the skin. Look for tighter knits and weaves if possible.
Addition of UV Absorbers
A fabric’s UPF can be increased by the addition of UV ray absorbers7. Examples of these UV ray absorbers are Tinosorb FD10 and zinc oxide11.
UV protection outfits are one effective, reliable and convenient way to keep your skin protected; against UVA and UVB rays. Whether you are indoors or outdoors, UV rays are a constant source of damage to the skin- sunburns, skin cancer and premature skin aging are some examples of unprotected UV exposure.
The advantage of using dedicated sun protective clothing is getting reliable and higher UPF values than regular clothing. Brands like Uniqlo offer a range of UPF clothing that can be very comfortable, breathable and stylish without breaking the bank.
Do you wear UPF clothing? Share with me your recommendations and experience!
1. Sunbathers’ application of sunscreen is probably inadequate to obtain the sun protection factor assigned to the preparation. Thomsen and Wulf. Photodermatol Photoimmunol Photomed. 1992-1993 Dec;9(6):242-4.
2. Sunscreen use at Danish beaches and how to improve coverage. Heerfordt. Dan Med J. 2018 Apr;65(4):B5476.
3. The relation between the amount of sunscreen applied and the sun protection factor in Asian skin. Kim et al. J Am Acad Dermatol. 2010 Feb;62(2):218-22.
4. The infant skin barrier: can we preserve, protect, and enhance the barrier? Telofski et al. Dermatol Res Pract. 2012;2012:198789.
5. Sunburns and risk of cutaneous melanoma: does age matter? A comprehensive meta-analysis. Dennis et al. Ann Epidemiol. 2008 Aug;18(8):614-27.
6. Apparel textiles and sun protection. Curiskis and Pailthorpe. Textile Magazine 1996;4:13-17.
7. Sun-protective clothing. Adam. J Cutan Med Surg. 1998 Jul;3(1):50-3.
8. Clothing as protection from ultraviolet radiation: which fabric is most effective? Davis et al. Int J Dermatol. 1997 May;36(5):374-9.
9. Protective effects of various types of clothes against UV radiation. Berne and Fischer. Acta Derm Venereol. 1980;60(5):459-60.
10. Revolutionary advances in sun-protective clothing–an essential step in eliminating skin cancer in our world. Edlich et al. J Long Term Eff Med Implants. 2004; 14(2): 95-106.
11. Flame retardancy and UV protection of cotton based fabrics using nano ZnO and polycarboxylic acids. El-Hardy et al. Carbohydr Polym. 2013 Jan 30;92(1):400-6.