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Sunscreen Guide | UVA vs UVB Rays
One day, I had my nephew ask, “What is sunscreen protecting us from?” In that moment, I laughed and responded, “It’s in the name, dummy…” Despite being technically correct and a little bit of a bully (out of love of course, haha), saying sunscreen protects us from the sun doesn’t paint the entire picture. Now, this wouldn’t be a sunscreen guide if we didn’t delve deeper into what sunscreen protects us from; ultraviolet (UV) rays. Understanding how sunscreen works and the different types of ultraviolet (UV) rays is crucial to protect our skin and maintain its health and radiance. So, “What’s the difference between UVA and UVB rays?” and “How does sunscreen protect us from the sun?”
How Does Ultraviolet Radiation Affect Us?
The sun emits various types of radiation, but when it comes to our skin, we need to be particularly concerned about ultraviolet (UV) radiation. This type of radiation can damage our skin cells, leading to premature aging, sunburn, hyperpigmentation, and even skin cancer. Not only do we need to worry about ultraviolet radiation, but we need to be aware that UV rays come in different wavelengths which require different levels of protection.
What’s the Difference Between UVA vs UVB Rays?
UV radiation can be classified into two primary types: UVA and UVB rays. Let’s break them down:
- UVA rays: These rays have a longer wavelength and penetrate deeper into the skin. They’re responsible for causing premature aging, such as wrinkles and age spots, and can also weaken the skin’s immune system. UVA rays are present all year round and can even penetrate through windows and clouds, making it essential to protect your skin daily.
- UVB rays: With a shorter wavelength, UVB rays mainly affect the outer layer of the skin, causing sunburn and playing a significant role in the development of skin cancer. Unlike UVA rays, the intensity of UVB rays varies depending on the time of day, season, and geographical location. Nevertheless, they’re still a significant concern, especially during peak sun hours.
How Does Sunscreen Work?
- Physical sunscreens: Also known as mineral sunscreens, they contain active ingredients such as zinc oxide or titanium dioxide that create a physical barrier on the skin, reflecting and scattering the UV rays. Physical sunscreens are the best sunscreen for sensitive skin and provide immediate protection upon application.
- Chemical sunscreens: These sunscreens contain organic compounds, such as avobenzone, octinoxate, tinosorb A, tinosorb B, and oxybenzone, that absorb UV radiation, converting it into heat, which is then released from the skin. Chemical sunscreens tend to be lightweight and less noticeable on the skin but may require a wait time of about 15-30 minutes after application for full protection. Chemical sunscreens are the best sunscreen for sports and outdoor sweating.