Physical versus chemical sunscreen filters. Both can provide effective protection. Whereas physical filters reflect or scatter the sun’s rays, chemical formulations filter radiation so that fewer rays reach the deeper levels of the skin.
Physical sunscreen filters do not penetrate the skin, they work like mirrors forming a protective layer on the skin that reflect and scatter the full spectrum of damaging UV radiation not just certain wavelengths. It is often referred to as a physical block or sun block. Physical filters are very photo-stable, which means they remain effective when exposed to sunlight. They also tend to be more water resistant than products with chemical filters.
Chemical sunscreens penetrate the skin but fewer rays reach the deeper levels. Depending on the formulation these products can protect against the full spectrum of damaging UV radiation, be photo-stable and water-resistant. They are generally referred to as sun screens.
Coverderm Filteray provides safe and effective protection against UVA, UVB and IR rays. The pro ducts are highly water resistant, have photo-stable physical and chemical filters and are long-lasting. The range includes products specially formulated for the face or body, and the face range include tinted products. There are also after sun care products for both face and body.
Water resistant
The FDA will no longer allow manufacturers to say their products are waterproof.
Look for products that are water-resistant. This means, the protection will be effective for 40 minutes in the water, then reapplication is necessary. Products that are labeled as very water resistant will typically last for 80 minutes in the water.
Broad spectrum
Broad spectrum means that the product can protect from both ultraviolet A (UVA) and UVB rays.
Sports
The FDA hasn’t approved this term for sun protection, but it’s a common indication of water and sweat resistance.
Sensitive skin
Although the FDA hasn’t approved the term “sensitive skin” for sun protection, it’s most likely an indication that the product is hypoallergenic and doesn’t include PABA, oils, or fragrances.
Before use, read the label to see if any of these ingredients may irritate your skin.
Ultraviolet radiation
Sunlight includes visible light, heat, and UV radiation. UV is divided into three types and is classified by wavelength.
UVA
Accounting for about 95 percent of the UV radiation reaching the Earth’s surface, UVA has a relatively long wavelength that can penetrate into the deeper layers of the skin.
Responsible for immediate tanning, it also contributes to skin wrinkling and aging, and the development of skin cancers.
UVB
Partially blocked by the atmosphere, medium wavelength UVB is unable to penetrate deeper than the superficial layers of skin.
UVB is responsible for delayed sun tanning and burning. It also can enhance skin aging and promote skin cancer development.
UVC
Short wavelength ultraviolet C (UVC) is totally blocked by the Earth’s atmosphere. It isn’t a concern with sun exposure. It can, however, be dangerous with exposure to an artificial radiation source.