We all are familiar with the SPF system which rates the level of UVB or sunburn protection. However, most are unfamiliar with the dangers posed by UVA rays. These rays are responsible for pre-mature aging and sun induced skin cancer. Critical Wavelength® (CW) is the most effective way to rate UVA protection. Solar radiation travels in waves. The wavelength corresponds to the solar energy of the wave. Solar radiation of 290nm to 400nm (the UVB-UVA range) is reproduced in a laboratory device designed to measure the amount of radiation absorbed by a sunscreen.

Starting at the beginning of the UVB range (290nm), progressively higher wavelengths of light are aimed at the sunscreen. A protective absorption curve or “umbrella” is produced. The Critical Wavelength defines how far this umbrella (actually 90% of the umbrella) extend into the UVA range. So for a Critical Wavelength of 383nm, 90% of the sunscreen’s protective “umbrella is between the beginning of the UVB range (290nm) to 383nm (see Graph below). The higher the number, the better. A sunscreen with a Critical Wavelength® over 370nm is considered by the FDA to provided ultimate Broad Spectrum UVA/UVB protection.

Now the FDA agrees and has issued a recent ruling on sunscreen labeling. According to the rule all Sunscreens that are defined as Broad Spectrum UVA/UVB protection must meet the 370nm Critical Wavelength® by summer 2012. Good daily UVA protection is very important. Chronic, long term, unprotected sun exposure causes micro-doses of UVA light to the skin. This UVA exposure produces damage over the years, by inducing a multitude of tiny “scars” where over time cause wrinkles, sun spots, loss of elasticity, thinning skin and a greater potential for skin cancer. As a pathologist, I have seen an increase in the numbers of skin carcinomas and melanomas which are diagnosed each year in an ever younger patient population.

According to the American Cancer Society, in 1985, one out of 150 people developed UVA related melanoma. The lifetime risk of an American developing invasive melanoma has now reached one in 87 one in 70 for white males) Melanoma rates are now rising faster than for any other form of skin cancer.

We believe LUCA® is the best UVA/UVB sunscreen available in the United States, because our formulations contain Polycrylene®, a novel Avobenzone stabilizer and strengthener. Avobenzone provides great UVA protection, but without the addition of Polycrylene®, it begins to breakdown after 10 minutes in intense sunlight.

The graph illustrates the protection with LUCA® versus a “good” broad spectrum formulation.