Don’t get us wrong, we LOVE the sun, but too much of a good thing can be problematic. And when it comes to exposing your largest organ (your skin!) to ultraviolet radiation, even a little bit can be unhealthy.

The sun emits 3 main types of ultraviolet (UV) radiation, UVA, UVB and UVC onto our planet. These categories are classified by the wavelength of the radiation, with longer wavelength radiation created by photons of lower energy and shorter wavelength radiation created by photons of higher energy. UVC radiation has the shortest wavelength of the three and is the most energetic and damaging, but thankfully our ozone layer absorbs it and it never reaches us. Thank you O3!

UVA and UVB on the other hand are able to pass through the atmosphere and reach our skin, with UVB penetrating as deep as our epidermis layer and UVA penetrating as deep as our dermis layer of skin. When exposed to this radiation, the DNA in our skin cells gets damaged. To defend against this, skin cells called melanocytes increase production of melanin, a pigment that helps shield the skin from more damage. We call increased melanin production a “tan”, but contrary to cultural perception, there is nothing healthy about it! While people often refer to tans as “healthy”, in reality they are a visual cue that the skin is under attack. 

Melanin helps absorb UV radiation and prevents some deeper tissues from getting exposed, but it’s not foolproof and skin cells can experience DNA damage. Fortunately the body has an amazing skill called nucleotide excision repair, a process where damaged DNA is identified and repaired. As incredible as this process is, our bodies are unable to keep up with all of the damage and over time we become increasingly susceptible to skin cancers.

For people with diseases like xeroderma pigmentosum (XP), the ability to repair the damaged DNA can be significantly reduced, making their skin especially sensitive to UV exposure. To read an inspiring story of an XP patient and how she uses our products to protect her skin, read Living In The Light on our blog here. 

Limiting how much your skin is exposed to UV radiation over your life is an important health strategy, but how can you do that while still enjoying the outdoors? In general, there are two methods available: sunscreen and sun protective clothing.

Sunscreen is useful but is often made of a concoction of chemicals, many of which have been shown to damage coral reef ecosystems. Many sunscreens also only protect against UVB radiation, so if you’re going to lather up, make sure to use reef safe formulations that are “broad spectrum” and provide both UVB and UVA protection.

Sunscreen strength is categorized by something called a sun protective factor (SPF), a measure of how much UVB radiation is required to produce a sunburn on skin covered in sunscreen relative to the amount of radiation required to produce sunburn on unprotected skin. Because of this complicated definition, SPF ratings are commonly misunderstood and figuring out exactly how much UV protection you’re getting can be unclear. To shed more light on SPF ratings, check out the FDA’s resource page here.

Thankfully, sun protective clothing is much easier to understand. Unlike sunscreen which is rated by the oddly defined SPF, clothing is categorized by the ultraviolet protection factor (UPF) which is a measure of how much UVA and UVB radiation is blocked by fabric. UPF is much easier to quantify and can be determined by physically measuring how much radiation a fabric blocks using a UV radiometer. UPF 50+ designates the highest achievable rating and describes a fabric that blocks over 98% of UVA and UVB radiation. 

Psychologically speaking, people tend to protect what they love, so if we want the world to take action on behalf of the ocean, it’s wise for us to create products that enhance your love of it. And since there is no better way to fall in love with nature than spending time in it safely, all of our products are built with UPF 50+ certified fabrics. 

Waterlust Chief Product Officer Laura Nottenkamper using an ultraviolet light radiometer as a secondary metric (all our fabrics are first independently tested and certified in a lab) to quantify how much UV radiation is blocked by a sample of fabric. We engineer our fabric to allow less than 20 µW/cm2 of total UV radiation to reach the skin during a bright sunny day, the equivalent of blocking more than 98% of incident UV radiation.