Sunscreens 2000 P2

Sunscreens 2000 -- What You Need To Know

A Time and Place for Sunburn

Sunburn doesn’t just happen on cloudless sunny days, or only on the beach, or only outdoors. UV radiation can easily penetrate window glass that hasn’t been treated to block the transmission of UV radiation. It is possible to be sunburned, while sitting near a window in your home, as you are reading a book. You can also be sunburned while driving to lunch or to Santa Barbara, if the vehicle windows don’t block UV radiation. Moreover UV radiation passes through clouds and can be reflected or filtered by them, so it is possible to get a sunburn on a cloudy day. UV radiation is also highly reflected by snow, the sand on a beach, and to a lesser extent even the water in a swimming pool in Las Vegas.

Most people have seen sunburn. It starts out as a generally pale reddened area that disappears shortly after the exposure, then becomes painful to the touch over the next 24 hours. The burn becomes maximal between 12 and 24 hours after the exposure. Then after three or four days, the erythematous (reddened) area begins to peel, and within a few more days has resolved. A more severe burn, which can have blistering, can require medical attention and considerably longer to heal. It is important to remember that you don’t need a sunburn in order to have a tan. A tan develops over the two weeks following the sun exposure.

UV-A is the desired ultraviolet radiation for tanning. It induces new melanin pigment formation within the stratum corneum of the epidermal layers of the skin and it is this pigment that creates the tan. As mentioned previously, UV-A radiation can cause sunburn but it is milder than that caused by UV-B over the same time of exposure. Therefore, even with 100% protection from UV-B radiation, sunburn can still occur from the UV-A radiation -- It just takes a little longer. This is why it is necessary to provide some level of UV-A protection with sunscreen products.

UV radiation is at its highest at noon on a sunny summer day and decreases steadily as sunset approaches. Although UV radiation peaks at noon, it is generally accepted that the prime sunburning time is between 10 am and 2 pm. However, the local landscape has a considerable impact as to how those UV radiation levels change during the course of the day.

Sunscreens are the best protection from the damaging UV radiation from the sun, whenever the skin must be exposed. Their liberal and repeated use is a necessity to prevent or minimize sunburn and to allow a natural tan to develop. Their improper use can lead to a sunburn.

There have been a few recent changes in sunscreen active ingredients and product labeling to eliminate deceptive or misleading statements and to improve product quality and safety. The FDA is responsible for regulating the manufacturing and labeling of sunscreens and cosmetic products. Considerable review and discussion has taken place since the last major revision of sunscreen regulations in 1978. The results of this review became final in May 1999, with the publication of new regulations. Manufacturers have until May 2001 to meet the new regulatory requirements or face fines, product seizures, or closure, as any product not meeting those requirements will be deemed misbranded and unfit for sale in the United States.

New product labeling on products with approved sunscreen active ingredients may now contain the statement: "Sun alert: Limiting sun exposure, wearing protective clothing, and using sunscreens may reduce the risks of skin aging, skin cancer, and other harmful effects of the sun." Products may also contain fewer active ingredients than in the past, because each active agent must contribute a minimum value of SPF 2 to the product and the minimum SPF value of the finished product must not be less than the number of active ingredients multiplied by 2. In addition, no longer is there a minimum concentration of any approved sunscreen active ingredient, so that only the amount sufficient to produce the desired effect may be used. There is also a point of diminishing return, where increasing the concentration of ingredients beyond a certain point may have a ceiling effect with no further increase in the SPF value, because of the effects of the ingredients on the skin.

Copyright 2000 Solumedia and Douglas Barcon, Pharm.D. All rights reserved. This information may not be published, duplicated, or transmitted in any manner without the express written permission of Solumedia and the author.

This page was last updated on 04/29/05.