Issue link: https://www.ascpskindeepdigital.com/i/1380992
Listen to the ASCP Esty Talk podcast at ascpskincare.com/podcasts 31 Sunscreen uses a variety of chemicals that absorb and scatter harmful UV rays before they penetrate the skin. They filter or screen the sun's UV rays and keep most out; however, some rays still penetrate into the skin. Sunscreens of this type are called chemical sunscreens. HOW UVA RAYS CAUSE AGING UVA rays, which penetrate deeper, are the more damaging rays—responsible for premature aging, wrinkles, and, in some cases, melanoma. UVA rays are long enough to reach the skin's dermal layer, damaging collagen and elastin tissue. They penetrate deep enough to stimulate the melanocyte; that's why UVA rays are considered the dominant tanning rays. (UVA rays are also used in tanning beds.) Also, the dermis contains regulating enzymes known as matrix metalloproteinases (MMPs). These specific enzymes break down and remove the old collagen and elastin fibers to make way for new ones being deposited by the fibroblast. A couple of MMPs you may know are collagenase and elastase. The MMPs are stimulated by UV radiation and become ravenous with chronic exposure to sunlight. When overexposure to UV radiation occurs, the MMPs will break down the very fibers they are designed to protect, and the dermis thins. When the dermis thins, skin wrinkling becomes evident. By knowing this, estheticians can make the case for sunscreen compliance, as there is a definite correlation between sun exposure and thinning dermis. DOES FITZPATRICK MATTER? Some clients believe their higher Fitzpatrick skin type does not require sunscreen, as they won't burn. Simply put, they don't think they need SPF and won't use it. However, we know just because the UVB rays (the burn rays) don't create a burn to alert us, UVA rays are still penetrating, and real damage is being done in the dermis where skin cancer (melanoma) arises. The bottom line is that everyone needs SPF to protect from UVA rays, as you don't see their damage. WATERPROOF SPF? There's no such thing as waterproof sunscreen. All sunscreens eventually wash off. Sunscreens labeled "water resistant" are required to be tested according to the required SPF test procedure. The labels are required to state whether the sunscreen remains effective for 40 minutes or 80 minutes when swimming or sweating, and all sunscreens must provide directions on when to reapply. The FDA only allows the claims "Water Resistant (40 minutes)" or "Water Resistant (80 minutes)" to be used on sunscreens sold in the US. Water-resistant sunscreens retain their stated SPF value after a certain time (either 40 or 80 minutes) in water or while sweating. 1 clark van der beken/unsplash SKIN PHYSIOLOGY How much to apply? • 1 ounce—fill a shot glass to fully cover your body. • Don't forget the tops of your feet, neck, ears, top of your head, and lips. • Apply 15 minutes before going outdoors. • Reapply every two hours, or after swimming or sweating. Skin Surface Epidermis Dermis UVA Type I Type II Type III Type IV Type V Type VI Light, pale white Always burns, never tans White, fair Usually burns, tans with diculty Medium white to olive Mild burns, gradually tans to olive Olive, moderate brown Rarely burns, tans to moderate brown Brown, dark brown Very rarely burns, tans very easily Black, very dark brown Never burns, tans very easily, deeply pigmented UVB Fitzpatrick Type UVC