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Physical vs. Chemical Sunscreen Technologies

While healthy skin is certainly a beauty benchmark, the skin itself performs so many essential tasks for our bodies to keep us healthy. This protective armor shields against bacterial infections, prevents moisture loss, regulates body temperature, produces vitamin D and reduces harmful ultraviolet (UV) damage. Though a huge asset to our body, our skin is also vulnerable to a wide range of environmental elements that cause damage including UV and infrared radiation, pollution and high-energy visible light (i.e. blue light). All of these contribute to free-radical damage or reactive oxygen species (ROS), causing DNA damage and photoaging.

Enter sunscreen. This superhero skin care product is celebrated for its ability to prevent trauma to the skin, which shows up as: sunburn, premature aging, fine lines, wrinkles, age spots, hyperpigmentation, rosacea, acne flares and photo carcinogenesis (pre-cancerous mutations). But, when it comes to sunscreen there has always been the question of which is best: chemical or physical formulations. Let’s dive a little deeper into where the differences lie.

Skin Damage

Some of the major external factors that cause skin damage include:

  • Ultraviolet radiation. This is caused by exposure to UVA and UVB rays (aging and burning rays). Long-term exposure releases matrix metalloproteinases, notorious enzymes that collectively degrade collagen and elastic fibers causing DNA damage by depleting the extracellular matrix (ECM). This inadvertently causes loss of structure revealed in the form of fine lines and wrinkles, sagging skin due to loss of elasticity, loss of plumpness, rough skin texture and age spots.

  • Infrared radiation. This comes from the sun’s heat, as well as tanning beds, and it causes inflammation like an increase in melanocyte activity that contributes to hyperpigmentation and sunspots. Infrared radiation can also accelerate and worsen skin conditions like melasma, chloasma, rosacea and acne.

  • Environmental pollution. Exposure to air pollution or airborne particles such as smog and smoke increases the generation of reactive oxygen species, causing inflammation that shows up as erythema (redness), irritation or dehydration, making the skin sensitive or sensitized.

  • High-energy visible (HEV) light spectrum. Excessive and long-term exposure to blue light, which is emitted from familiar electrical devices like TV screens, computer screens, smart phones and tablets, produces damaging free radicals such as nitric oxide. These free radicals disrupt the skin’s microbiome causing inflammation and imbalance, which can be corrected by topical antioxidants, anti-inflammatories and prebiotics to restore skin homeostasis.

Sun Care Technologies

The good news is that consistent use of sunscreen is known to significantly reduce the development of disorders and diseases of the skin such as actinic keratosis, basal cell carcinoma, squamous cell carcinoma and melanoma. Continuous research efforts to improve the technology that drives sun care innovations are rapidly making great advancements. New developments include the microencapsulation of chemical sunscreen ingredients using inert Tetraethoxysilane Polymers to improve stability, reduce systematic absorption, increase efficacy and diminish allergic reactions. An example of this is EnviroScreen Technology, which is an encapsulating process that provides mineralbased, chemical free, novel coating technology combining zinc oxide, titanium dioxide and iron oxides with proprietary blends of antioxidants, hydrators and vitamins.

There is also a technology incorporating Silicone Elastomer blends, which boasts multiple features and benefits that is on the rise. This technology provides benefits to sunscreen formulas including: the ability to reduce fine lines and wrinkles, boost SPF, provide scar protection, penetrate faster, provide a more uniform application and deliver filmforming capabilities. It is also compatablie with physical and chemical sunscreen formulations.

Gone are the days when high sun protection factor was the order of the day, or when sunscreen was only applied at the beach or during outdoor recreation. We know that daily, incidental exposure drives the lionshare of sun damage. Sourcing highquality, raw materials that have been tested for efficacy, absorption, protection levels and spreadability are important to effectively protect the skin.

Choosing the Right Formulation

The FDA has approved 16 active UV filter ingredients for organic and inorganic sunscreens. UV filters are the component that provides sunscreen with their desired protection factor (SPF). The SPF of a sunscreen is predominantly based on blocking UVB rays. It does not measure the effectiveness against blocking UVA rays, which can penetrate below the dermis causing cellular damage.

Innovations incorporate broad spectrum UVA and UVB filters, which are classified in three different wavelengths: longest (UVA1), intermediate (UVA2) and shortest (UVB). Sunscreen formulations are now sophisticated enough to use hightech ingredients like iron oxide, InfraGuard, antioxidants and peptides to provide effective protection and promote healthy barrier function, leaving the integrity of the skin intact and youthful.

InfraGuard. This ingredient is the synergistic combination of tara tannins and sunflower sprouts. Tara is a South American native plant; it’s a free radical scavenger rich in pyrogallic acid and modest amounts of catechin derivatives. They offer powerful photo protection with antiinflammatory benefits. Sunflower sprouts are rich in vitamins A, D, E and B Complex including Folate. They also contain high levels of potassium, calcium, magnesium and iron. This formidable combination delivers comprehensive protection against oxidative stress caused by UV and infrared light exposure, damage caused by pollution and degradation of collagen and elastin. Studies on the benefits of InfraGuard show an improvement in the quality and density of the skin. These restorative ingredients work to keep the skin balanced.

Micronized Zinc Oxide. This is known to be safer than nanoparticles because the size of the particles are larger than nanoparticles, therefore less irritating. It warms up with the heat of the body and blends in better on the skin, especially in darker Fitzpatrick skin types IVVI, without the white cast associated with physical sunscreens. Micronized zinc oxide also provides better and more effective UV protection.

Iron Oxides. In physical sunscreen, iron oxides protect the skin against visible light and UVA radiation and enhance the absorption of these external factors. Iron oxide is excellent for protecting the skin against hyperpigmentation. The incorporation of iron oxides increases the efficacy of multifunctional coated mineral actives.

There are many sunscreen options on the market from aerosol sprays to gels to creams and lotions. Thanks to technological advancements, darker skin tones can enjoy the benefits of sunscreen without the white cast.

Physical vs. Chemical

The main distinction between physical and chemical sunscreens is that the mechanism of physical sunscreen creates a protective barrier on the surface of the skin to block, reflect and deflect UV rays.

PHYSICAL SUNSCREEN. Physical sunscreens are recommended for all skin types, especially for those with preexisting conditions like rosacea, acne, eczema, all types of pigmentation and sensitive skin. Physical sunscreens are the preferred option, and they are excellent for postprocedure care to immediately protect the skin following facial treatments, waxing, chemical peels and laser resurfacing. Sunscreens that do not contain nanoparticles are classified as reef safe.

Physical sunscreens that contain the synergistic combination of micronized zinc oxide, titanium dioxide and iron oxide are recommended to better protect the skin as opposed to chemical sunscreens.

The advantage of a physical sunscreen is that it provides immediate protection, making it an excellent feature for those on the go! Active minerals such as micronized zinc oxide and titanium dioxide with the incorporation of iron oxide offer maximum physical protection.

CHEMICAL SUNSCREEN. A chemical sunscreen containing actives like oxybenzone, octisalate, homosalate, avobenzone and octocrylene, absorbs UV rays and then diffuses them. The heat from this process tends to trigger skin conditions such as rosacea, acne, hyperpigmentation and other sensitivities. Chemical sunscreens must be applied 1520 minutes prior to sun exposure. They also tend to be more emollient, providing extra moisture to dry, balanced and combination skin types. Chemical sunscreens are not recommended for oily skin that is prone to acne and breakouts, sensitive skin, rosacea, eczema and all types of pigmentation. They are contraindicated for pregnant and lactating women as well.

Sun Care in the Spa

Whether a brand manufactures or a consumer uses a chemical sunscreen is a subjective choice. Product availability is also impacted by distribution in certain regions of the world. Places like Hawaii have banned chemical sunscreens with oxybenzone or octinoxate, as they are said to harm coral reefs. Consumers are required to provide a medical prescription as proof that the use of sunscreens with these ingredients is to specifically prevent sunburn. Allergies to sunscreen are not as common as sensitivities and reactions. Skin care professionals are encouraged to conduct a patch test prior to making a sunscreen recommendation. It is also important to educate clients on the proper use of sun care as to when and how they should apply it.

Sunscreen formulations are uniquely curated to possess specific features and benefits based on key active ingredients desired by a brand. So, when it comes to determining which sunscreen is best for the consumer, the answer is whichever one is most appealing to them, whether physical or chemical, as regular compliance is what makes a sunscreen effective. Skin care professionals exist to educate and guide clients and patients on the best option for their skin type, tone and conditions.

This article originally appeared in the February issue of Skin Inc Magazine


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