What Is SPF?

The sun protection factor (SPF) measures how long a sunscreen can protect your skin against harmful sun radiation. Keep reading to learn more about SPF.

Sun protection factor (SPF) measures how well a sunscreen can protect your skin against harmful radiation from the sun. The SPF number determines the sunscreen's effectiveness. SPF helps you know how long your skin will be protected against sunburns. The level of Protection depends on your skin type, the year's season, and how long your body takes before you start sunburning. The levels of SPF range from low Protection, medium protection, and high Protection to very high Protection. You should know that sunscreen is only part of sunburn protection, not the overall defense against skin damage. Besides, applying a liberal amount of sunscreen helps you achieve the level of Protection labeled on your sunscreen. Wearing sunscreen protects you against sunburn, prevents DNA damage, reduces your risk of developing skin cancer, and prevents uneven skin pigmentation, among other benefits.

What Is SPF?

SPF stands for Sun Protection Factor. According to the Foods and Drugs Administration (FDA), "sun protection factor (SPF) is a measure of how much solar energy (UV radiation) is required to produce sunburn on protected skin (i.e., in the presence of sunscreen) relative to the amount of solar energy required to produce sunburn on unprotected skin." Sunburn protection increases with SPF value. SPF number also shows you the percentage of UV rays absorbed by the sunscreen. For example, SPF15 absorbs approximately 90% of UVB rays, while SPF30 absorbs approximately 96%. Besides, no sunscreen can absorb up to 100% of the sun's UV rays. The highest percentage of UV rays absorbed by most sunscreens is up to 98%.

How Does It Work?

SPF indicates the duration your skin is protected against sunburns. Different skin types have different results from sun exposure. SPF number only shows the extent of Protection. How SPF works depends on your skin type, the season of the year, and the time it takes before you start getting sunburned. For example, some people get sunburned after 5 minutes of exposure to the sun, while others get sunburned after 10 to 30 minutes. The average time for a person to start getting sunburned is between 5 to 30 minutes. Therefore, if you get sunburned after five minutes of sun exposure without any sunscreen, applying sunscreen with an SPF20 will protect you five minutes times 20 long before you begin sunburned again. A product containing a higher SPF number provides the highest level of Protection.

Levels of SPF

• Low Protection (has SPF of 15 and below)
• Medium Protection( has SPF between 15 and 29)
• High Protection (has SPF between 30 and 49)
• Very high Protection (has SPF above 50)

Things to Check Out for

There are things to check out concerning the sunscreen's SPF. Note that UV radiation can get through your skin even with the highest SPF. No sunscreen can completely block sunburn or skin damage. Sunscreen is only partial Protection against sunburns and not an overall defense against skin damage.

The second thing to know is that SPF is determined by applying a generous amount of sunscreen. This means that to achieve the level of Protection indicated on the sunscreen, and you should apply a liberal amount of sunscreen thick enough to achieve the Protection indicated. You may also reapply your sunscreen every 2 to 3 hours as some of it may be rubbed off by a cloth or some off when you sweat

Before using any sunscreen, make sure you check its expiry date. Your sunscreen may fail to work out well if some of the active ingredients have been broken down.

Why Do You Need SPF? Benefits of Wearing Sunscreen

Protection against Sunburn

Sunlight is essential to your health. It is the main source of vitamin D that supports bone health, lowers blood pressure, improves mental health, and prevents illness. However, sunlight can sometimes be dangerous. It consists of two harmful rays, UVA and UVD rays. These two rays are linked to skin damage, such as the formation of wrinkles and some skin cancers. Even small sunburn can increase your risk of getting skin cancer. When your skin absorbs these harmful radiations from the sun, they damage your skin cells and destroy their genetic material. Sunscreen protects your skin against these harmful rays by absorbing and scattering sunlight.

Prevents Early Aging

According to Shanbhag et al. (2019), UV radiation is a causative factor for skin aging. Sunburns cause almost 95% of aging signs. Your skin can age prematurely when exposed to sunlight for a long time. Introducing SPF sunscreen into your daily skincare routine prevents the formation of fine lines and wrinkles that may contribute to premature aging.

Reduce Your Risk of Skin Cancer

Applying sunscreen prevents skin pre-cancers and minimizes your risk of developing skin cancer. Sunscreen reduces the harmful effects of sunlight exposure.

Prevents Skin Redness and Inflammation

Napolitano et al. (2015) revealed that lengthy sunlight exposure might result in severe skin reddening and inflammation. As your skin gets sunburned, it turns red. More blood is then directed to the affected area to repair and may result in skin inflammation. Applying SPF can reduce skin reddening and inflammation.

Prevent DNA Damage

Sunlight can cause DNA damage and trigger photoaging and skin carcinogenesis. According to Schuch et al. (2017), many of the harmful human health effects that result from sunlight exposure are associated with a chain of events that begins with the formation of DNA damage. These lesions can lead to inflammatory and immunosuppressive processes in the epithelial tissue, accelerated aging, and tumor development."

Prevents Blotchy Skin and Discoloration

Skin discoloration or hyperpigmentation is when your skin inconsistently becomes darkened or discolored. Skin discoloration may be hereditary or caused by sunburn. Krutmann et al. (2021) showed that wearing sunscreen helps you avoid dark spots and any uneven skin pigmentation resulting from sunlight exposure.

Conclusion

Sun protection factor (SPF) measures how much UV radiation is required to produce sunburn on protected skin relative to the amount required to produce sunburn on unprotected skin. The levels of SPF range from low Protection, medium protection, and high Protection to very high Protection. How SPF works depends on some factors, such as your skin type, the time of the year, and how much time your body takes before you start getting sunburned. Wearing sunscreen improves your skin health by protecting you against sunburn, preventing DNA damage, avoiding uneven skin pigmentation, and preventing skin cancer, among other benefits.

References

Krutmann, J., Schalka, S., Watson, R. E. B., Wei, L., & Morita, A. (2021). Daily

Photoprotection To Prevent Photoaging. Photodermatology, Photoimmunology & Photomedicine, 37(6), 482-489.

Napolitano, A., Panzella, L., Monfrecola, G., & d'Ischia, M. (2014). Pheomelanin‐

Induced Oxidative Stress: Bright And Dark Chemistry Bridging Red Hair Phenotype And Melanoma. Pigment Cell & Melanoma Research, 27(5), 721-733.

Schuch, A. P., Moreno, N. C., Schuch, N. J., Menck, C. F. M., & Garcia, C. C. M. (2017).

Sunlight Damage To Cellular DNA: Focus On Oxidatively Generated Lesions. Free Radical Biology And Medicine, 107, 110-124.

Shanbhag, S., Nayak, A., Narayan, R., & Nayak, U. Y. (2019). Anti-Aging And

Sunscreens: A Paradigm Shift In Cosmetics. Advanced Pharmaceutical Bulletin, 9(3), 348.