Sun Protection Factor (SPF) tells you how long it takes for ultraviolet B (UVB) rays to turn your skin red when you use sunscreen, compared to how long the skin would last without the product. So the SPF number gives you an idea of how long you can stay in the sun without getting burned. For example, if you normally burn without sunscreen within 10 minutes and you have applied a generous dose of sunscreen with an SPF number of 15, you should be protected from sunburn for 150 minutes. This does not mean that you are protected from other radiation damage. A broad spectrum sunscreen is also required to provide protection in the UVA range. An SPF rating does not measure Ultraviolet A (UVA) protection.
What is the difference between a sunscreen and a sunblock?
Under the new FDA final rule for labeling and testing sunscreen products, the word "Sunblock" is no longer allowed. The FDA is trying to clear up any confusion the public may have, or a sense of false security. However, the titanium dioxide and zinc oxide in our bases physically block UV rays by acting like tiny mirrors on the skin that reflect and refract the rays. Most chemical sunscreens have very efficient absorption capabilities through the UVB, partly the UVA and in some cases infrared wavelengths. Once the chemicals have absorbed their limit, the sunscreen stops being effective. (Absorption is the process of "losing" light when it strikes a material. The light is not actually lost, but is converted into another energy, such as heat.)
In sun protection: development: evaluation and regulatory aspects, Nicholas J Lowe (editor), renowned dermatologist and clinical professor of dermatology at UCLA School of Medicine, takes a closer look at mineral UVA blockers , stating that a new subcategory of physical blockers, micronized reflective powders, have recently been made available by various manufacturers. Unlike traditional physical blockers, micronized reflective powders are less visible, but provide broad-spectrum protection against ultraviolet radiation (UVR). These should be useful in UVR sensitive patients who are resistant to older physical blockers for cosmetic reasons. An additional advantage is that they do not cause photosensitivity. Not all mineral powders have an SPF rating. If so, the SPF rating should be stated on the label.
How much sunscreen should be applied to get the advertised protection?
According to the American Academy of Dermatology, you should use enough sunscreen to generously cover any skin not covered by clothing. a small amount, sufficient to fill a shot glass, is considered the amount needed to cover the exposed areas of the entire body. You should apply our sunscreen liberally and evenly to face and body 15 minutes before sun exposure and reapply approximately every two hours (experience shows it provides much longer protection), or after sweating or perspiring heavily according to packaging guidelines. jane iredale sunscreens are water resistant for up to 40 minutes. This means that the sunscreen remains effective for 40 minutes while you perspire or swim.
Which are the most damaging rays?
UVB rays were once considered the culprits because they penetrate and affect the epidermis, but UVA rays are now known to be just as, if not more damaging. According to Dr. Madhu A. Pathak of Harvard Medical School, "there is much evidence that the primary biological action of UVA radiation involves DNA damage." UVB emissions from the sun undergo significant seasonal variations; however, the UVA emissions do not change noticeably over the course of the year. The amount of solar UVA reaching the Earth's surface is much greater than UVB. UVA also penetrates most window glass and many plastics that do not transmit UVB. Always check that your sunscreen protects against UVB and UVA, but keep in mind that regardless of the advertising, no sunscreen product filters all UV rays. The best defense is to tryTry to minimize your exposure between 10 a.m. and 4 p.m. The effects of infrared rays (felt by the body as heat) are not fully known, but according to Drs. Lorraine and Albert Kligman of the University of Pennsylvania: "They cannot be ignored in relation to photoaging".
Are sunscreens effective against melanomas?
It is not safe to rely solely on sunscreens to prevent melanoma, which is now the 10th most common cancer. Most dermatologists find that it takes more than 20 years for melanoma to develop. Those with this cancer today were exposed to the sun's harmful rays twenty years ago, before effective sunscreens were developed. dr. Ceilley, former president of the American Academy of Dermatology, states, "Sun protection should begin in childhood and continue throughout life. Overwhelming evidence supports the beneficial effect of sun protection in not only preventing painful sunburns, but also preventing skin aging and skin cancer, including melanoma."
Is there such a thing as a safe brown color?
No! A tan is a sign of injury. It's the body's attempt to increase sun protection after the skin has already been permanently damaged by an overdose of ultraviolet radiation! More than 90% of visible signs of aging are due to sun exposure. And that means all sun exposure, because ultraviolet radiation damage is cumulative. Walking to the mailbox, getting in the car and sitting by the window all count! Unprotected exposure to the sun is like being in a time machine fast-forwarding.
Can sun damage be reversed?
Some damage can be reversed or minimized, but only if the skin is always protected from the sun. There are many excellent skin care products and nutritional supplements on the market that can significantly help the skin repair sun damage. But they don't do much good if not combined with sun protection - so don't forget to wear your sun protection and a hat!
What are some of the effects of sun exposure?
Lines, wrinkles and sagging of the skin are the direct result of sun damage to the underlying collagen and elastin fibers. Hyperpigmentation can be caused or exacerbated by solar radiation from the melanocytes (the pigment-producing cells), which in turn cause overproduction of melanin, which is basically the body's attempt to protect itself. Add hypopigmented macules, telangiectasias, and raised, rough precancerous actinic keratoses (Sunspots are the most common skin precancers) and the tanning results aren't pretty.