Deciphering Sunscreen Ingredients
Buying sunscreen for some is simply a matter of looking at the SPF rating and thinking, the higher the number, the more protection is given to your skin and the longer the person can stay out in the sun. But, that is not exactly true. Most other countries limit the SPF value advertised to 50 because of misconceptions the public has. Many times, a SPF of 80 is really no more effective than one of 50, yet the consumer pays more for the illusion. Another illusion is buying a brand. Nearly all sunscreens contain the usual types of chemicals in varying percentage levels. So, whether you buy a high end name sunscreen or one from K-mart for far less, the cheaper one is probably as good, it may even be better! Sunscreens with higher SPF do not last or remain effective on the skin any longer than lower SPF. All sunscreens must be reapplied every two hours regardless of SPF due to degradation from water, absorption, and breakdown of chemicals.
Suntan screens are all about defending from the sun's UVA and UVB harmful rays. UVA can be damaging without you feeling anything, pain wise. They can age your skin and cause skin cancers. Tests on sunscreen are measured over all wavelengths in sunlight's UVB–UVA range (290–400 nm), along with a table of how effective various wavelengths are in causing sunburn. SPF 15 means that 1/15th of the burning radiation will reach the skin, assuming sunscreen is applied evenly. This means if a person with no sunscreen burns after being 10 minutes in the sun, with 15 SPF, the person can be in the sun for 150 min. before burning. The best protection still is zinc oxide or titanium oxide, bar none. These are usually in cream or paste and are noticeable when applied (which is why they are unpopular!).
The first sunscreen appeared in 1946 and by the 1950's consumers were buying Coppertone products. SPF ratings first appeared in 1974 and water resistant screens began in 1977.
When buying sunscreen, look for the following ingredients:
1. Homosalate - a UV protectorate blocking wavelength from 295 nm to 315 nm spectrum, it also does not dissolve in water. Try to get 15%.
2. Oxybenzone - This is your UVA-UVB broad spectrum protector from 270 to 350 nm with absorption peaks at 288 and 350 nm. You want this to be near 6%.
3. Octocrylene - Another organic UVA-UVB protector from the sun's 280 to 320 nm wavelengths.Try to get 5% or more.
4. Avobenzone - This absorbs all the UVA wavelength's from the sun. The downside is that this chemical degrades rather fast when exposed to the sun. Most sunscreens contain about 3-4% of this.
5. Octyl Salicylate - Another UVB protector, most screens contain about 5%.
6. Titanium Oxide - One of the best protectors, usually contains 2%.
7. Octinoxate- Blocks UVB rays and insoluble water. Used in true "waterproof" creams. Usually in 7% or more amounts.
The above ingredients are generally for 30-60 SPF sunscreens.