What you need to know about SPF

What is SPF Sunscreen?

SPF, or Sun Protection Factor,is a measure of how well a sunscreen will protect skin from UVB rays, the kind of radiation that causes sunburn, damages skin, and can contribute to skin cancer.

  • If your skin would normally burn after 10 minutes in the sun, applying an SPF 15 sunscreen would allow you to stay in the sun without burning for approximately 150 minutes (a factor of 15 times longer). This is a rough estimate that depends on skin type, intensity of sunlight and amount of sunscreen used. SPF is actually a measure of protection from amount of UVB exposure and it is not meant to help you determine duration of exposure.
     

  • For best protection, experts recommend using a minimum SPF sunscreen of 15, applying the proper amount (2mg/cm2 of skin, or about one ounce for full body coverage), and reapplying every 2 hours.
     

  • Most people under-apply sunscreens, using ¼ to ½ the amount required. Using half the required amount of sunscreen only provides the square root of the SPF. So, a half application of an SPF 30 sunscreen only provides an effective SPF of 5.5!


The SPF (Sun Protection Factor) scale is not linear:

  • SPF 15 blocks 93% of UVB rays
     

  • SPF 30 blocks 97% of UVB rays
     

  • SPF 50 blocks 98% of UVB rays

So, one way of looking at this is that SPF 30 sunscreen only gives you 4% more protection than SPF 15 sunscreen.

Chemical or Physical?

You might hear the word chemical and think “no way!” but it is really important to know that not all chemical sunscreens are harmful (Image skincare Prevention + is a safe choice) A physical sunscreen uses ingredients such as Zinc Oxide and Titanium Oxide to physically block the Ultraviolet Rays. Chemical Sunscreens utilise ingredients such as Octinoxate.

Pros of using physical sunscreen

Offers protection against both UVA and UVB rays and is naturally broad spectrum

  • Protects from the sun as soon as it’s applied, no wait needed

  • Lasts longer when in direct UV light (but NOT when doing physical activities that cause the skin to get wet or sweat)

  • Less likely to cause a stinging irritation on the skin, making it better for sensitive skin

  • Better for those with heat-activated skin (like those with rosacea and redness) since it deflects the heat and energy given off by the sun away from the skin

Pros of using chemical sunscreen

  • Tends to be thinner and, therefore, spreads more easily on the skin, making it more wearable for daily use

  • Less is needed to protect the skin because there is no risk of no spaces between the sunscreen molecules after application

  • The formula is easier to add additional treatment ingredients to, such as peptides and enzymes, which offer other skin benefits

Image Skincare have mastered combining Sun Protection with beneficial skincare, our skin experts can help you select the perfect one for your needs

Chemical, Physical, UVA, UVB, Broad Spectrum, SPF 15, SPF 30, SPF 50 are all terms you have probably heard but what does it all mean?

Lets Start with the types of light exposure from the sun - UVA and UVB rays

Ultraviolet light is invisible to humans, because it has shorter wavelengths than the light we can see. Within the UV spectrum, there are two types of rays that can damage the DNA in your skin cells and lead to skin cancer. It’s important to protect your skin from both types:

  • UVB rays cause sunburn and play a key role in developing skin cancer. A sunscreen’s SPF number refers mainly to the amount of UVB protection it provides.

  • UVA rays cause skin damage that leads to tanning as well as skin aging and wrinkles. The shortest wavelengths of UVA rays also contribute to sunburn. It’s important to look for the words “broad spectrum” on the label, which means the product has ingredients that can protect you from UVA as well as UVB rays. 

And what about SPF? SPF stands for Sun Protection Factor

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