What is SPF in Sunscreen? How Does it Work?

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It is very common to see the acronym SPF on sunscreens or some skincare products. But do we understand what it is about?


How do we know if the SPF we are choosing is correct? We will solve these and more doubts in this article by Jess Beauty so that you can select your products based on your skin needs.


SPF: meaning and calculate



SPF (Sun Protection Factor) is a term used to measure the effectiveness of a sunscreen product against the sun's UV rays. It indicates how long you can be in the sun without burning compared to the time it would take to burn without protection.


For example, if your skin normally takes 10 minutes to burn without sunscreen, using sunscreen with SPF 30 will give you approximately 30 times more protection. It means you could be in the sun for about 300 minutes (10 minutes x 30) without burning.


Note that SPF only measures protection against UVB rays, which are responsible for sunburn. However, you should also protect yourself against UVA rays associated with premature skin aging and other damage.


Therefore, it is advisable to use broad-spectrum sunscreen, which protects against both UVB and UVA rays. In this way, you will be protecting your skin from the harmful effects of the sun, such as burns, premature aging, and the risk of developing skin cancer.

Recommended SPF


The recommended SPF can vary depending on different factors, such as skin type, geographic location, and sun intensity. However, most dermatology experts recommend sunscreen with an SPF of at least 30.


An SPF 30 provides high and effective protection against UVB rays. It blocks around 97% of UVB rays, which means you can stay in the sun 30 times longer without burning compared to using no sunscreen. It applies when used correctly and reapplied according to the product instructions.


If you have very fair skin, sensitive skin, or are prone to burning easily, you may want to use sunscreen with an even higher SPF, like 50 or even 50+. These offer more intense protection, but it is important to note that no sunscreen gives complete protection.


Combine sunscreen with other protection measures, such as seeking shade, wearing protective clothing, and limiting direct exposure to the sun during peak hours.


Can it be applied to all skin types?


The SPF (Sun Protection Factor) fits all skin types. Sun protection is essential for everyone, regardless of skin type or tone.


As we said, for people with fair and sensitive skin, it's especially important to use a broad-spectrum sunscreen with an adequate SPF to protect against UVB and UVA rays. Fair skin tends to be more prone to sunburn and at higher risk of long-term sun damage.


For people with brown or dark-toned skin, it's a common misconception that they don't need sunscreen. Although people with darker skin have more melanin, which gives them some natural protection against UV rays, they are still at risk of sun damage and should protect themselves with sunscreen.


Choose a sunscreen that suits your skin type and personal preferences. There are sunscreens specially formulated for oily skin, sensitive skin, or acne-prone skin. You can opt for lotion, cream, gel, or spray sunscreens, depending on your preferences and needs.


When should you use sunscreen?


Sunscreen should be used whenever there is sun exposure, regardless of the season. Here are some times to apply sunscreen:


  • During Sun Exposure: If you're going to be spending time outdoors, whether at the beach, at the pool, playing outdoor sports, or just walking in the sun, you should apply sunscreen before going outside. Be sure to cover all exposed areas of your skin, including your face, neck, arms, and legs.


  • Every day: Even if you're not outdoors all day, it's a good idea to apply sunscreen as part of your daily skincare routine. Even sun exposure during everyday activities like walking down the street or sitting near a window can contribute to long-term sun damage.


  • On cloudy days: Although the sun may be hidden behind clouds, UV rays can penetrate them and damage the skin. Therefore, it is important to apply sunscreen even on cloudy days.


  • During all seasons of the year: UV rays can affect the skin at any time, even in winter. Therefore, it is advisable to use sunscreen during all seasons to protect the skin from long-term sun damage. Remember to apply sunscreen liberally and reapply every two hours or more often if you're sweating or swimming.


Sunscreen combined with other skincare products


You can combine sunscreen with other skin care products as long as you follow some basic guidelines. Here are some recommendations:


  • Moisturizer: You can apply your usual moisturizer before applying sunscreen. Allow the moisturizer to absorb into the skin before applying the sunscreen to avoid diluting its effectiveness.


  • Makeup: If you wear makeup, you can opt for products with built-in sunscreen. However, the amount of sunscreen in makeup may not be enough to provide adequate protection. Therefore, apply a separate sunscreen before applying makeup, especially if you will be out in the sun for long periods.


  • Topical Treatments: If you use other topical skin care treatments, such as serums, creams, or acne, it's best to apply them before sunscreen. Allow the topical treatments to absorb into the skin, then apply the sunscreen on top.

Note that the combination of skin care products can vary based on individual needs and the specific products used.


Plus, some skincare products also have a sun protection factor, although they may not be designated as SPF.


These products may indicate on their label the level of sun protection, generally represented by a number followed by the letter "SPF" or "UPF" (Ultraviolet Protection Factor).


However, these products' sun protection may be less compared to dedicated sunscreens, especially in terms of protection against UVB and UVA rays.


Jess Beauty wants you to take care adequately of your skin. That is why we recommend you use a broad-spectrum sunscreen with an adequate SPF and combine it with other protective measures, such as seeking shade, wearing protective clothing, and limiting direct sun exposure during peak hours.

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