how sunscreens work
Sunlight contains damaging ultraviolet B and A rays. Energetic UVB rays are typically associated with sunburn; UVA rays are less energetic, but penetrate more deeply into the skin and can cause sunlight-induced premature skin aging, wrinkling and age spots. Both UVB and UVA rays damage skin and can lead to skin cancer – even on cloudy days!
Sunscreens absorb, reflect or scatter this UV light. Inorganic or “physical” sunscreens form a film that reflects or scatters UV light before it penetrates the skin. These sunscreens include zinc oxide or titanium dioxide. Organic or “chemical” sunscreens absorb UV rays before they can cause damage. Examples include avobenzone and oxybenzone, which protect against both UVB and UVA rays.
A good sunscreen product should be “broad spectrum” – containing ingredients that protect against both UVB and UVA rays. All Mary Kay® sunscreen products provide this broad-spectrum protection in either a physical or chemical form.
What Is SPF?
Another sunscreen consideration is the SPF, or sun protection factor. This number is calculated by comparing the amount of time needed to produce sunburn on protected skin to the amount of time needed to cause sunburn on unprotected skin. The amount of time it takes you to sunburn depends on your skin type, and the SPF number you need depends on how much time you expect to be outdoors.
Interestingly, SPF protection does not actually increase proportionately with a designated SPF number. For example, SPF 4 blocks 75 per cent of sunburn damage; however, it may not provide broadspectrum protection. An SPF 15 screens 93 per cent of sunburn damage; and an SPF 30 screens 97 per cent of sunburn damage. Most products with an SPF 15 or greater will provide broad-spectrum protection against both UVB and UVA damage, such as our Mary Kay® SPF 30 Sunscreen.
So what’s the benefit of very high SPF products (SPF 70+) that are now available in the marketplace? They are good for people with highly photosensitive skin, but it’s important to note that they do not provide incrementally more protection. For example, an SPF 70 blocks 98.6 per cent of sunburn damage, only slightly higher than an SPF 30 product.
You’ll also want to know that, for daily use – particularly on the face – an SPF 15 to SPF 30 is
recommended. And, of course, all Mary Kay® daily use sunscreens meet this criteria!
Use And Application
Be sure to apply sunscreen to all exposed areas and pay particular attention to the face, ears, hands and arms. Most people apply only 25 to 50 per cent of the recommended amount of sunscreen, so be sure to coat the skin liberally! The average amount needed to properly cover exposed areas of an adult is approximately 30 mL (one ounce). And remember that that lips can sunburn too, so be sure to apply a lip balm that contains sunscreen with an SPF 15 or higher, such as Mary Kay® Lip Protector Sunscreen SPF 15 with zinc oxide for broad-spectrum protection.
Sunscreens should be reapplied regularly – at least every two hours – or after swimming, perspiring heavily or towel-drying. Water-resistant sunscreens may lose their effectiveness after 40 minutes in the water; very water-resistant sunscreens may lose their effectiveness after 80 minutes in the water. Mary Kay® SPF 30 Sunscreen is designed to be very water-resistant for up to 80 minutes of protection in the water, and is specially formulated for use on the face and body.
Shelf Life
Sunscreens normally remain stable and at their original strength for up to two years. But if a
120 mL bottle of sunscreen is used properly, it should last only four usages. Remember to discard sunscreen that is past the expiration date or is more than two years old.
To recap, the best sunscreen is the one you actually put on! Use a broad-spectrum SPF 15 or higher sunscreen daily on all exposed skin because every day is a sun day!
