Sunscreen Ingredients

Sun protection is an essential part of daily life. It is estimated that 90% of non-melanoma skin cancer and 65% of melanoma skin cancer are associated with exposure to UV radiation from the sun. (Premature) Photoaging and photodamage to the skin is the number one cause of skin aging. In addition, UV radiation also contribute to catarats and skin color change — hyperpigmentation, (age spots, brown spots or liver spot). Exposure to sun light can trigger free radicals production in the skin and body which is one of the main causes of aging. Therefore, sunscreen ingredients is an essential component of a day anti-aging skin care regimen.

The sun produces a range of ultraviolet (UV) radiation, of which UVA and UVB affect our skin. UVA rays have wavelengths of 320 to 400 nm; UVB rays have wavelengths of 290 to 320 nm. UVB radiation causes sunburn. UVA is responsible for most of the photo-aging damage. the premature wrinkles, loss of elasticity, sagging (laxity), hyperpigmentation, and a dry, dull, leathery skin texture.

Sunscreen products are considered over-the-counter drugs in the United States and as such are strictly regulated by the FDA. Sunscreens provide protection from sunburn and some amount of sun damage. SPF (sun protection factor) is a number that is assigned to a product that identifies its ability to protect the skin from sunburn or to protect the skin from turning pink or red when exposed to sun. SPF numbering is regulated by the FDA, and is a measure of the amount of time a person can stay in the sun without getting burned if a sunscreen is applied. Because sunburn results from UVB radiation, not UVA radiation, SPF is primarily a measure of UVB protection. At this time, there is no numbering system to indicate the level of protection a sunscreen can provide from UVA radiation, which affects the deeper layers of skin.

Repeated exposure of unprotected skin while tanning may increase the risk of skin aging, skin cancer, and other harmful effects to the skin even if you do not burn. Sunscreen should not be used to prolong time spent in the sun. Even with a sunscreen, you are not going to prevent all the possible damage from the sun. Some of the newer research in the last several years shows that for the sub-erythemal doses [exposure to the sun that does not cause reddening of the skin], as little as one-tenth the energy needed to get a sunburn, starts the process of skin damage of one sort or another. The public under-applies sunscreens by as much as half of the recommended amount. Consequently, the study argued, consumers are receiving only half of the SPF protection they believe the product provides.

What Are the Active Ingredients in Sunscreen?

Chemical Ingredients

Broad-spectrum sunscreens often contain a number of chemical ingredients that absorb UVA and UVB radiation. Many sunscreens contain UVA-absorbing avobenzone or a benzophenone (such as dioxybenzone, oxybenzone, or sulisobenzone), in addition to UVB-absorbing chemical ingredients (some of which also contribute to UVA protection). In rare cases, chemical ingredients cause skin reactions, including acne, burning, blisters, dryness, itching, rash, redness, stinging, swelling, and tightening of the skin. Consult a physician if these symptoms occur. These reactions are most commonly associated with para-aminobenzoic acid (PABA)-based sunscreens and those containing benzophenones. Some sunscreens also contain alcohol, fragrances, or preservatives, and should be avoided if you have skin allergies.

Physical Ingredients

The physical compounds titanium dioxide and zinc oxide reflect, scatter, and absorb both UVA and UVB rays. These ingredients, produced through chemical processes, do not typically cause allergic reactions. Using new technology, the particle sizes of zinc oxide and titanium dioxide have been reduced, making them more transparent without losing their ability to screen UV. Summary All of the previously mentioned chemical and physical ingredients have been approved by the FDA. The following table lists these ingredients and includes information regarding the type and amount of ray protection that they provide and their class.

Sunscreens Ingredients

 

 

 

 

 

 

 

 

 

 

 

 

Your sunscreen should have at least an SPF 15. Since SPF is a measure of UVB protection only, you need to be sure your sunscreen also has ingredients to block UVA rays. To be truly effective and beneficial for skin, sunscreens must protect skin from both the sun’s UVA and UVB radiation. In the United States, there are four ingredients approved by the FDA that protect across the full UVA range: titanium dioxide, zinc oxide, avobenzone (also called Parsol 1789 and butyl methoxydibenzoylmethane), and Mexoryl SX (ecamsule). Outside the United States, Tinosorb is another. Mexoryl SX is a L’Oreal-patented sunscreen ingredient that received FDA approval in July 2006 for use in a single sunscreen, Anthelios SX SPF 15 (see below for more detail). It is also important to note that all sunscreen ingredients break down to some extent when exposed to sunlight, which is why reapplication of sunscreen is critical to maintaining protection.

Mexoryl SX

Mexoryl SX. (ecamsule, also know as terephthalylidine dicamphor sulfonic acid), is a synthetic sunscreen agent developed and patented by L’Oreal and used in the company’s sunscreen products sold outside the United States since 1993 (first approved for use in Europe in 1991). In July 2006, the FDA approved the use of Mexoryl SX in the United States, but only in a single sunscreen product, La Roche-Posay’s Anthelios SX SPF 15 (L’Oreal owns La Roche-Posay). The FDA did not approve Mexoryl SX for use in any other sunscreen. Anthelios SX will list Mexoryl SX as ecamsule on the label along with the other actives avobenzone and octocrylene (both of these sunscreen ingredients have been approved for use in the United States for years). L’Oreal blitzed the media with press releases about this approval, touting Mexoryl SX’s improved stability when compared with avobenzone, or intimating that it is the best UVA sunscreen available. According to sunscreen expert Ken Klein, president of Cosmetech Labs, although Mexoryl SX does not degrade after hours of sun exposure at the same rate as avobenzone, it does indeed break down, losing 40% of its protective properties. Studies have shown that after controlled doses of UV exposure, avobenzone breaks down at a rate of 65%, so Mexoryl SX does have a slight stability edge. However, avobenzone can be made more stable by combining it with other active ingredients, specifically octocrylene. Outside the United States, Tinosorb (another sunscreen active) is often used to enhance the stability of avobenzone. Interestingly, the press releases touting Mexoryl SX’s superiority as a UVA-protecting sunscreen ingredient don’t mention the active ingredients titanium dioxide and zinc oxide, which have long been available worldwide in sunscreen formulations, and that offer protection across a greater range of wavelengths with almost no possible risk of irritation, which is a pervasive problem with synthetic sunscreen agents such as Mexoryl SX. UVA rays have a range of 320–400 nm. Although Mexoryl SX protects within this range, titanium dioxide and zinc oxide protect across the entire UVA and UVB spectrum, from 230 to 700 nanometers. Mexoryl SX is an effective UVA sunscreen agent, but it is by no means the only or absolute best one to look for.


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