Every dermatologist ever and every skin routine tutorial recommends you “Wear your sunscreen every single day”. Well, is this sunscreen ritual in your skincare worth the hype? What is the SPF number on my sunscreen?
Settle in, we have got answers for you here!
SPF stands short for Sun Protection Factor or simply the amount of UVB protection that you receive when wearing the product. SPF number tells you how long the UVB rays would take to redden your skin when wearing your sunscreen as directed, compared with the amount of time without applying any sunscreen.
Does my SPF cover UVA & UVB rays?
There are three types of Ultraviolet rays or Ultraviolet radiation which are UVA, UVB, and UVC classified according to the wavelength.
Let’s memorize them through simple mnemonics,
- UVA rays: UV-Aging –> Overexposure causes premature aging and may lead to melanoma or skin cancer.
- UVB rays: UV-Burning –> Overexposure causes painful sunburn and may lead to skin cancer.
- UVC rays: UV-Cancelled –> Dangerous but completely filtered out by the earth’s atmosphere.
The medium wavelength UVB just penetrates the superficial skin layers and causes the burning effect. Whereas the longer wavelength UVA penetrates skin deep which makes it responsible for most of the tanning effects.
Why is SPF important?
Undeniably sunlight is required to produce Vitamin D, the unique vitamin that reaches the recommended level upon exposure to the sun, thus contributing to bone health and general well-being. However, a bit of overexposure to this strongest source of ultraviolet radiation in our environment could lead to changes in the DNA at the cellular level and surfaces later as leathery dry skin, dark spots, fine lines and wrinkles thereby prematurely aging the skin, which is called photoaging, or sun damage. Therefore, sticking to broad-spectrum sun protection which covers both UVA and UVB protection at an early age retains healthy skin and keeps you off sun-induced skin cancers.
What does SPF 15 and SPF 30 mean?
SPF 15 blocks 93% and SPF 30 blocks 96.7% of UVB rays. Having said that, SPF 15 allows 7% of UVB rays to reach your skin and SPF 30 allows about half or 3.3% of UVB rays when compared to SPF 15. Depending on your skin sensitivity, the SPF 30 would take 30 times longer to burn than if you weren’t wearing any sunscreen.
What does SPF 50 and SPF 100 mean?
SPF 50 blocks 98% and SPF 100 blocks 99% of UVB rays. Well, you now know the amount of UVB your sunscreen allows to reach your skin. Remember though, NO sunscreen blocks 100% from UVB rays and the level of protection gets smaller and smaller up the line which means your SPF 70 blocks less than 1% more of UVB compared to your SPF 50 sunscreen.
Takeaway:
- Use a Broad-spectrum sunscreen for UVA and UVB protection.
- Sunscreen with SPF 30 or above is only a part of the Sun Smart Ritual for sun defense.
- SPF sweats off and rubs off. Reapply sunscreen every 2 hours especially when outdoors.
Disclaimer: The content provided on this blog is for informational purposes only and should not be considered as a substitute for advice from a Healthcare Professional.
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