Fashionclick^®  Beauty

SUN FILTER BASICS

Little by little, as consciousness of the dangers of over-exposure to the sun's rays has increased within the population, cosmetic companies have moved rapidly to increase their sun protection factors. Just 10 years ago, almost nobody used 15 or 30 SPF sunscreens, unless they were allergic to sunlight  or suffered from some type of intolerance. It is also true that there were not that many high-protection sunscreens or total sun-blocking ones as there are now. Thus, we have gone from applying your typical carrot oils, with which you would get a deep tan in a few days, to using higher-quality products with more elevated protection factors.

The number of filter you are going to use is not the sole measurement of the effectiveness of the new sunscreens. You must also know that there are two basic sun-protection systems available: physical filters and chemical filters.

Chemical filters depend on their chemical structure to absorb the energy of the ultraviolet rays and can cover a broader or narrower spectrum. Most of them only protect from UVB rays, and are not sufficiently effective against UVA ones. This is why they are often combined with physical filters in order to strengthen their action. This type of filters can cause allergies or irritations in the long run, especially if you have sensitive skin. Their main inconvenience, though, is that they progressively loose their effectiveness, which is the why they should be reapplied every twenty minutes.

Physical filters are more difficult to apply, but are very effective and cause fewer allergies than chemical ones. They function as a protective barrier, which works as a reflecting shield dispersing the sun's rays. Physical filters are also called mineral screens or micropigments. Most of them have a mineral base (titanium dioxide, zinc oxide) but, although effective, they are used less often because they are more difficult to make. Some brands have already achieved sunscreens formulated with chemical filters that solve these inconveniences.

Also with antioxidants. After having chosen the protection system that you favor most, you can then consider other ingredients that are included in the formulas of the newest sunscreens. The most recent are antioxidants, which have the power to stop free radicals. They stop premature aging and can be added in the form of vitamins, nourishing oils, melanin...

Immunoprotection. The sun is a cancer-causing element that diminishes our immune system by attacking the cells' DNA. Cosmetic formulas incorporate new immunoprotection systems, which preserve the skin's vital defenses protecting the Langerhans cells. This is the first time that an outside-in protection has been included. Although all skin types can benefit from this cosmetic advance, these products are specially made for children because their immune system is feebler than that of an adult.

Until recently there were different methods of measuring the sun protection factors available. The German and European DIN system, that of the FDA (USA) that is very extended in Europe, and the Australian SAA. Each of them presented important discrepancies, especially within 

WITH THE PERFECT INDEX

high protection factors. The COLIPA Association has now created its own method for measuring the solar protection factors in Europe. Even after this recent agreement, according to Dr. Francisco Balaguer, "It still continues to be a hot issue, because there has been no unanimous agreement among photobiologists."

The COLIPA method is the European one and, since its measurements are quite similar to that of the American system, it is also being adopted in Europe. All modern sunscreens have a similar protection index. Yet, the Australian method is the only one that is different because it includes an official-adopted system for the measurement of UVA radiation in vitro, although there is no legal obligation to measure it nor mention it on the packing.

WHAT IS THE SUN PROTECTION FACTOR (SPF)?

The number that is found on a sun product indicates the protection coefficient against UVB rays. In the valuation of a solar protection cosmetic the filter number is obtained by dividing the minimal erythema dose in protected skin by its minimum in unprotected skin. In other words, if your skin can exposed to the sun without a minimal perceptive burn for 10 minutes, using a protection factor of 6 you can stay outside 6 times more than if you were wearing no protection at all. In this case an hour: 6 x 10 = 60 minutes. In principle, the SPF or IP (Protection Index in Spanish) only protects against UVB rays unless the packing indicates the contrary. The novelty this year is the incorporation of filters against the UVA rays.

ACCORDING TO STATISTICS

The hours in which sunlight is more damaging - when only 30 to 50% of the UVB rays are filtered - is between 10 in the morning and 2 in the afternoon (14H) solar time. On a cloudy day, the risk of sunburn still exists, because 90% of the ultraviolet radiation can pass through the cloud cover. The risk of getting burned also increases with the altitude: every 300 meters (900 feet) it rises 4%. At an altitude of 1.500 meters (4,500 feet) the power of the UVB rays is 20% higher than at sea level. If we add to this that 80% of the sun's rays are reflected by the snow, while sand only reflects 25% and water 5%, we can say that sun and snow is the most dangerous mix of all.