The important Chemicals in Sunscreen
The sun’s energy is critical for supporting life on Earth. Solar radiation, or ultraviolet light, provides photosynthesis for plants, heat for our environment, and healthy substances like Vitamin D. But sunlight also has harmful effects to humans if we are exposed too long. To help prevent sunburn and other solar damage, many of us wear sunscreen, which contains various chemicals.
The sunscreen business is huge. It is getting bigger each year as our population expands and people have more leisure time to spend outdoors. We also are experiencing noticeable climate change where scientists find we are getting more solar radiation than ever before. That increases consumer demand for sunscreen products, which are estimated at a global market of $5.6 billion. In America, $1.85 billion is spent each year.
One of the biggest fears people have from sun ray overexposure is developing skin cancer. Sunburn is bad enough. Developing a deadly disease like melanoma on your skin is downright terrifying. According to the United States Environmental Protection Agency (EPA), more than 1 million Americans develop some form of skin cancer each year. The EPA estimates that ultraviolet (UV) radiation over-exposure is associated with 65 percent of melanoma cases and 90 percent of other skin cancer diagnosis.
In this article you will learn:
Having the Right Chemicals in Sunscreen
The key to preventing skin damage and disease is limiting your exposure to direct UV radiation. Using sunscreen is highly effective for absorbing or blocking UV rays, as long as you have the right sunscreen ingredients. The EPA publishes a paper called The Burning Facts, where they provide clear information on sunscreen products and their correct use. The EPA paper lists all common organic chemicals and non-organic minerals used in common sunscreen products. They also rate how effective each chemical is at reducing effects of UV-A and UV-B rays.
Although visible light is what we see, this photon spectrum is not harmful. It is what you do not see coming from the sun that can be dangerous. Ultraviolet light is different from visible light on the energy spectrum. Two parts of the ultraviolet wave scale are UV-A at 320-400nm and UV-B at 290-320nm. The two spectrums affect humans in different ways, and that is why chemicals in sunscreen are designed to cooperate in dissipating both wave types.
Ultraviolet-A is always present and in consistent quantities. Clouds have little effect on UV-A rays, and these waves penetrate deep below your skin’s surface. Ultraviolet-B sun rays have shorter lengths. Clouds and haze slow down and help block UV-B, which only affects your skin’s surface. UV-B rays are also more intensive in summer, hence a requirement for different sunscreen chemical blends during different seasons.
Chemicals in Sunscreen and their Purpose
Sunscreens products have two divisions. One sunscreen type is chemical-based which uses active ingredients. That means each chemical has certain qualities that absorb ultraviolet light and regulate it by dispersing solar heat before it does any damage. The most common active ingredients or chemicals in American sunscreen products are oxybenzone, octinoxate, PABA, homosalate, octocrylene, octisalate, avobenzone, and Mexoryl SX or Ecamsule.
While mineral-based sunscreen products are still chemicals, the sunscreen industry groups them separately. This is because non-organic — or non-carbon based chemicals — reflect ultraviolet light rather than absorb it as organic compounds do. Mineral-based sunscreen contents act like blockers that cover your skin surface and mirror harmful rays away from your body. The two common minerals in sunscreen are titanium dioxide and zinc oxide.
Referring back to the EPA’s The Burning Facts paper, they have an interesting summary about sunscreen ingredient effectiveness against both UV-A and UV-B radiation. This chart, borrowed from the Food and Drug Administration (FDA), lists the common organic and mineral chemicals in sunscreens, including how they perform on a scale rating of extensive, considerable, limited, and minimal effectiveness. Let us take an in-depth look at each of the 10 most common chemicals found in American sunscreen products.
Oxybenzone was once the most common sunscreen ingredient — that is because it is effective at blocking both UV-A and UV-B solar radiation. Oxybenzone is an organic-based product with the chemical name benzophenone-3. This chemical readily blends with other chemicals used in sunscreen. You will also find oxybenzone used as a UV inhibitor in plastics and many different types of consumer goods, like hairsprays and cosmetics.
While oxybenzone is very effective at blocking ultraviolet rays, there is some controversy about its side effects. Some consumers report using sunscreens with high oxybenzone concentration gives them allergic reactions with skin itching and redness. The sunscreen industry and the EPA cannot find sufficient proof to support anti-oxybenzone claims. It is still approved and forms part of most organic-based sunscreen applications — however, its popularity has waned over the past few years. Oxybenzone is extensively effective at blocking UV-B rays and has a considerable effect on UV-A rays.
Octinoxate is now the most common sunscreen chemical. It is similar in composition and effectiveness to the once-popular oxybenzone chemical. The main difference is that octinoxate has few allergy or discomfort reports, and the sunscreen industry responded by moving toward octinoxate as a preferred sun-absorbing chemical. Because they have similar characteristics, you will rarely see octinoxate and oxybenzone used in the same sunscreen product.
Octinoxate is a common term for two slightly different chemicals — one form is octyl methoxycinnamate. The other is ethylhexyl methoxycinnamate. Both substances have similar properties, except octyl methoxycinnamate mixes with other chemicals somewhat easier. Aside from sunscreen products, you will find octinoxate as a leading lip balm ingredient. On the EPA/FDA scale, octinoxate is extensively effective against UV-B radiation and has limited effectiveness on UV-A rays.
PABA is the acronym for para-aminobenzoic acid. It was once the chemical of choice in early sunscreen products. In the 1950s and 1960s, practically all American sunscreen chemical-based sunscreens depended on PABA for UV protection — it is rarely used now because consumers reported side effects related to sunscreen products containing PABA. It is also because modern chemistry has found new and improved sunscreen products.
One benefit consumers value in the few remaining PABA-containing sunscreens is that it is a natural chemical found in folic acid. Those who can tolerate PABA-based sunscreens appreciate that it’s not synthetic like octinoxate and oxybenzone. On the EPA/FDA rating scale, PABA has minimal effects on UV-A radiation but is extensively powerful against UV-B rays.
Homosalate is an organic chemical compound or ester derived from salicylic acid and 3,3,5-trimethylcyclohexanol. It is one of the few sunscreen chemicals with a distinct fragrance. Nearly half of U.S. sunscreens use homosalate as a chemical UV filter for absorbing harmful solar radiation. It mixes well with other chemicals and is a stable compound.
Sunscreen manufacturers rarely use homosalate as an individual sunscreen chemical. It tends to break down quickly, and it needs the support of sturdy chemicals like avobenzone, oxybenzone, and octinoxate. Some people have reported side effects from homosalate, but it has good water resistance, which makes homosalate-based sunscreens popular with swimmers and beach-goers. Homosalate has an EPA/FDA rating as extensive for UV-B and minimal for UV-A radiation.
Octocrylene is a clear, colorless and odor-free chemical made by combining diphenyl cyanoacrylate with 2-ethylhexanol. It provides a moisturizing effect on your skin, as well as adding to ultraviolet light protection. You will often find octocrylene blended with avobenzone, as the two chemicals complement each other well.
Octocrylene works as a binding agent with other sunscreen chemicals, too. It is a staple ingredient in general skin care products, but octocrylene has its critics. Because octocrylene acts as a photosynthesizer, some people feel it has a side effect triggering free radical release. Scientific literature is vague about actual studies on this. As a sunlight-absorbing chemical, the EPA/FDA schedule lists octocrylene as having limited effectiveness on UV-A rays, but it is extensively effective against UV-B radiation.
This chemical has similar properties to homosalate. Formally called octyl salicylate or 2-ethylhexyl salicylate, octisalate is a common organic compound used in absorbent-type sunscreens. It is a good chemical for water exposure applications, but octisalate has a tendency for UV-breakdown in short spans. Chemists overcome this deficiency by ensuring octisalate has supporting chemicals like oxybenzone, octinoxate or avobenzone.
In the sunscreen chemical business, octisalate is a penetration enhancer. Its chemical properties allow octisalate molecules to sink deep into your skin tissues. This lets other sunscreen chemicals travel with it for an overall deep penetrating effect. Octisalate has an EPA/FDA rating as extensively effective for UV-B absorption but minimal impact on UV-A radiation.
Avobenzone is the leader of modern sunscreen organic chemicals. There are no adverse health aspects to avobenzone and plenty of positive ones. The only chemical drawback is that avobenzone is slightly unstable when applied by itself. That is overcome when blended with other synthetic chemical compounds.
The chemical name for avobenzone is butyl methoxydibenzoylmethane. The oil-soluble chemical was patented in 1973. In the past decade, avobenzone has made its mark on American sunscreens. Today, it is considered the safest sunscreen chemical additive. According to the EPA/FDA chart, avobenzone is extensively effective at absorbing UV-A rays and limited in its UV-B protection.
Mexoryl SX is the trade name for Ecamsule. Chemically, this product is titled terephthalylidene dicamphor sulfonic acid, and it is a benzylidene derivative. Do not be concerned with the scientific name — Mexoryl SX is perfectly harmless with excellent photostability. It is water-soluble and provides excellent sunscreen protection.
L’Oreal has proprietary brand name rights on Mexoryl SX, so sunscreens containing Mexoryl SX or Ecamsule are only L’Oreal products. Being photostable, Mexoryl SX will not degrade under UV light exposure. The EPA and FDA consider Mexoryl SX as having extensive UV-A protection and limited resistance to UV-B light.
Titanium Dioxide (TiO2) is technically a chemical sunscreen product, but it is non-organic. Titanium dioxide is a natural mineral product that happens to have excellent sun-blocking properties. What also makes titanium dioxide different from synthetic chemical compounds is that titanium dioxide in sunscreen reflects UV rays rather than absorbing them.
Sunbathers have applied titanium dioxide to their skin for decades. Also known as titania, this mineral-based material blocks UV radiation and deflects it back into the atmosphere like a mirror. Something to know about using titanium dioxide as a sunscreen is that it is not mixed with any organic, carbon-based chemicals that absorb sunlight. In the EPA/FDA view, titanium dioxide has considerable UV-A blocking effectiveness and gives extensive efficiency in reflecting UV-B rays.
If avobenzone is the queen of organic sunscreen chemicals, the zinc oxide is the king of mineral sunscreen bases. Zinc oxide (ZnO) is an old standby at the beach — you may recognize it as the pasty white noses on lifeguards. Zinc oxide naturally occurs in the Earth, and it has been used as sun protection for centuries.
Like titanium dioxide, zinc oxide is a sun blocker. It does not absorb ultraviolet radiation. Instead, zinc oxide breaks radiation particles and scatters them away from your body. It is tremendously effective as a natural sunscreen. However, some people do not appreciate the oily feel of zinc oxide on their skin.
Modern technology has overcome most of this greasy feel and look by converting raw zinc oxide into nanoparticles. According to the EPA/FDA schedule, zinc oxide is the best sunscreen there is. It has a dual spectrum rating as extensively effective for blocking both UV-A and UV-B radiation.
Active Ingredients vs. Inactive Ingredients
You will hear the terms active and inactive when discussing sunscreen ingredients. In essence, active ingredients in sunscreen are those that have a therapeutic effect on your body. They are ingredients like the organic, carbon-based chemicals found in UV-absorbing sunscreen products. They are also the inorganic mineral compounds found in sun blockers.
Inactive sunscreen ingredients refer to additives meant to enhance active elements that do not perform a particular action on your skin. Rather, inactive sunscreen ingredients perform a support service to the workhorses acting within sunscreen products. Those actions include stabilizing, preserving and carrying sunscreen applications evenly across your exposed skin.
Mineral Sunscreen Components
Mineral sunscreens are naturally occurring products made of raw materials harvested directly from the earth. They are still chemicals, as they have a chemical signature or identity. However, mineral sunscreens are not synthetically produced in laboratories. Titanium dioxide and zinc oxide are the only two mineral sunscreens available on the American market.
SPF Boosting in Sunscreen
An SPF booster is a product that increases the efficiency of sunblock and reduces how much sunscreen penetrates the skin. Alone, SPF boosters cannot meaningfully contribute to SPF. The average efficiency, or SPF to 1 percent sunscreen used, for day-wear SPF products is around 1.8, while beach sunscreens typically have an efficiency level of 2.5. When you use an SPF booster, you can increase these numbers based on the types of sunblock used and their base formulation.
On top of this, SPF boosters improve the resistance your sunscreen has against wash and wear. Most work by enhancing a sunscreen's UV absorption and maintaining the thickness of each layer of sunblock on the skin for a more extended period. Other functions include improving UVA coverage, boosting sunscreens' UV scattering ability, increasing sunblocks' UV stability, and decreasing skin erythema.
Chemicals in SPF Boosting
Did you know you can find SPF boosters in the form of anti-inflammatory agents?
The different kinds of SPF boosters include:
Emollients prolong UVA coverage by enhancing the critical wavelength, help dissolve crystalline sunblocks like Benzophenone 3 or Avobenzone, and increase the photostability of Avobenzone.
These polyacrylates or polyurethanes function by forming films that cause UV absorption levels to increase and maintaining a thicker film of sunscreen on the skin for an extended period of time.
Non-polymeric and polymeric waxes increase UV absorption and scatter by forming sunblock-containing particles in emulsions of oil in water.
Choose Brenntag as Your Chemical Distributor
Choosing a sunscreen product is a personal endeavor. You need to consider the intensity of the sun rays you will be exposed to and decide whether you want a sun-blocking product or a sun-absorbing sunscreen. You will also have to decide on the sun protection factor (SPF). This is a value given to how well a specific product protects you from UV rays. Most experts recommend you choose a sunscreen that is SPF 30 or higher.
Sunscreen product manufacturers also have to make a choice. They must select a chemical supply company they know they can trust. Brenntag North America is a leading specialty and chemical distributor to the sunscreen industry. We know having the right chemicals in your sunscreen can make all the difference in your sun protection plan.
Brenntag North America is headquartered in Reading, PA. From here, we supply sunscreen manufacturers with specific application technology, value-added services, and extensive customer support. We believe in effectively connecting our chemical manufacturers with the chemical users. Brenntag has a total line of more than 10,000 products, and our one-stop-shop service caters to over 185,000 customers worldwide.
For more information on Brenntag North America and how we serve the sunscreen chemical industry, call us today at 610-926-6100.
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