What is UVA and UVB in Sunscreen

Nearly everyone is guilty of picking out sunscreen from the shelf without understanding everything the label means. Broad-spectrum protection, UVA, UVB, HEVIS, SPF, and PA+ begin to look like letters and numbers when you don’t know the science behind sun protection. Don’t remain negligent about the harms of ultraviolet rays and dive into understanding UVA and UVB in sunscreen as simply as possible.

Keynotes:

• UVA and UVB are UV rays with different wavelengths that damage the skin in different ways.
• UVA causes ageing, pigmentation, and dermal skin damage, while UVB leads to sunburn and surface skin damage.
• Broad-spectrum sunscreens protect you from both UVA and UVB, with SPF shielding from UVB and PA ratings from UVA.
• Selecting the right sunscreen with added antioxidants, HEVIS protection, and a suitable formulation is key.

We all know that the sun emits harmful ultraviolet rays (UVR) that your skin needs protection from. These ultraviolet or UV rays have differing wavelengths, which damage your skin in different ways. Based on these wavelengths, the UV rays are divided into UVA (long-range UV with 315-400 nm) with longer wavelengths and UVB rays with shorter wavelengths (280-315 nm).

In the middle of scorching days, when the sun is above your head, the radiation contains 95% UVA rays and 5% UVB. UVB rays are much less compared to the long-range UVA; they are highly energetic and can cause serious damage to your skin. UVC rays also exist, but they are largely removed from the atmosphere by the ozone layer along with UVB.

With the basics of radiation cleared out, it’s important to know the difference between UVA and UVB rays and why your skin needs protection from both.

Due to their differing wavelengths, UVA and UVB rays damage different parts of the skin differently. Here’s all you need to know -

UVA – Causes Premature Aging

• Photoaging & Pigmentation:

  UVA has a longer wavelength. This allows them to reach the dermal layers, or the deeper layers of your skin and damage the collagen and elastin, the structural support of your skin. This process is known as photoaging, where you begin to experience wrinkles and fine lines at a younger age due to collagen breakdown. They can also damage skin cells and cause pigmentation or sun spots that darken with age.

• Indoor radiation:

  All the skincare blogs and experts urge you to use sunscreen indoors as well, thanks to UVA rays. UVA rays can penetrate through windows and glass and can cause skin damage even when you are in the safety of your home. This means that they can even pass through clouds to affect your skin even when it’s overcast.

• Oxidative Stress:

  Compared to UVB, UVA radiation induces major oxidative stress in cells. This means that UVA can lead to unstable electrons that damage healthy skin cells, leading to dark spots and pigmentation. UVA rays are largely used in tanning beds.

UVB – Causes Sunburn and Skin Damage

• Sunburn:

  UVB has a shorter wavelength and affects the outermost layers of your skin. Sunburn can damage your skin barrier, turning your skin red, inflamed, sensitive, and more vulnerable to other skin concerns.

• DNA damage:

  While UVB rays only work on the surface of your skin, they are still high energy and cause serious damage. UVB rays are largely responsible for DNA damage that turns into serious conditions like melanoma and skin cancer. UVB rays can also damage your eyes and cause cataracts.

• Blistering:

  UVB rays are also associated with blistering, which means that they can lead to fluid-filled blisters on the skin that are painful and can compromise your skin structure.

Both UVA and UVB rays damage the skin differently, which is why protection from both these rays is an absolute must. This is where broad-spectrum sunscreens come in. These sunscreens that have both SPF (Sun Protection Factor) and PA (Protection Grade of UVA) are crucial for shielding your skin all year long. Here’s what these acronyms mean:

SPF (Sun protection Factor)

SPF or sun protection factor is a measure of how well a sunscreen protects you from UVB rays. The number written in front of SPF is the strength of your sunscreen. It roughly denotes how much UV would be needed to cause a sunburn on your skin. The higher the number, the more UV is required to cause sunburn, and the stronger the sunscreen. Simply put, as the SPF value increases, sunburn protection increases.

• SPF 15: Low protection against UVB and sunburn
• SPF 30 or 50: Adequate to high protection against UVB and sunburn

Remember that SPF has very little to do with how long a sunscreen will protect you from UVB. This is because the intensity of radiation changes throughout the day. Your skin may face very high UVB radiation in just a few minutes during afternoons, this may not be the case at dusk or dawn. It also depends on your skin tone, the region you live in, and how much sunscreen you have used.

PA (Protection grade against UVA)

The protection grade of the UVA (PA) system was developed in Japan. This grading scale uses plus (+) symbols to indicate the level of UVA protection your sunscreen offers. Typically, sunscreens range from PA+ to PA++++, with the former being the lowest and the latter indicating the highest level of UVA protection.

• PA+: Lowest protection against UVA
• PA++++: Highest protection against UVA

While SPF measures the protection against sunburns, UVA protection systems measure the ratio of the minimal dose of UVA required to create pigmentation in the skin. However, UVA can still cause oxidative stress, which can lead to dark spots.

While looking for products with broad-spectrum protection, check if the sunscreen has these markers:

• SPF 50+:

  Sunscreens with SPF 50+ offer very high protection against UVB.

• PA/Broad Spectrum:

  Sunscreens that have PA rating or are marked as ‘broad-spectrum’ help you get UVA protection too, shielding your skin from photoaging and spots.

• HEVIS Protection:

  HEVIS is the high-energy visible light or blue light emitted by the sun. However, it’s also commonly produced by electronics like our phone and laptop screens. HEVIS can also have damaging effects, like UV rays, causing oxidative stress and dark spots. This is why sunscreens with HEVIS protection are crucial.

• Antioxidants:

  Look for sunscreens with gentle antioxidants like Licochalcone A and Glycyrrhetinic Acid, which can help you combat the oxidative stress caused by any UV exposure and stress during the day.

• Formulation:

  Heavy, creamy sunscreens may not suit all skin types. They may clog pores and exacerbate problems like acne and pimples. This is why choosing sunscreen formulations is crucial, too. Try gel-based sunscreens for oily skin, hyaluronic acid sunscreens for hypersensitive and dry skin, and Thiamidol-infused sunscreen for pigmented skin.

With your basics cleared on the differences between UVA and UVB, it’s time to select the perfect sunscreen that fits into your regimen. Make sure that you’re applying sunblock every morning, after skincare and before makeup, to keep your skin shielded from the long-term harms of the sun. Browse through the Eucerin Sun range and find a formula that suits your skin type.

1. What is the difference between UVA and UVB rays?

   UVA rays have a longer wavelength, are more prevalent, and can cause photoaging and pigmentation. UVB rays have a shorter wavelength, are more energetic, and can cause sunburn, eye damage, and skin cancer.

2. How does broad-spectrum sunscreen protect against UVA/UVB?

   Broad-spectrum sunscreens have both UVA and UVB filters, which keep your skin safe from both types of radiation.

3. What SPF is best for UVA and UVB protection?

   Look for sunscreens with SPF 50+ and PA+++ for ideal UVA and UVB protection.

4. Should I wear sunscreen indoors?

   Yes. UVA rays can pass through clouds, glass, and windows to damage your skin. This is why you must wear sunscreen indoors, too.

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• MD Anderson Cancer Center. (n.d.). What’s the difference between UVA and UVB rays? MD Anderson Cancer Center.
• Fabbrocini, G., De Padova, M. P., Tosti, A., & Costanzo, L. (2022). Mechanisms of UV-induced damage and defense strategies in skin: The role of antioxidants. International Journal of Molecular Sciences, 23(15), 8243.
• U.S. Food and Drug Administration. (2022, September 8). Sun Protection Factor (SPF). U.S. Food and Drug Administration.
• WebMD. (n.d.). The difference between UVA and UVB rays. WebMD.