Chemical sunscreens are the most commonly used and are available in a variety of moisturizers that protect against ultra-violet light. Moisturizers come in several forms — ointments, creams/gels, and lotions. Ointments are mixtures of water in oil, usually either lanolin or petrolatum. Creams are preparations of oil in water, which is the main ingredient. Creams must be applied more often than ointments to be most effective. Lotions contain powder crystals dissolved in water, again the main ingredient. Because of their high water content, they feel cool on the skin and don’t leave the skin feeling greasy. Although they are easy to apply and may be more pleasing than ointments and creams, lotions don’t have the same protective qualities. You may need to apply them frequently to relieve the signs and symptoms of dryness. They contain one or more of the UV radiation-absorbing chemicals. Some of the most widely used chemical groups that block UVB radiation are PABA (p-aminobenzoic acid), PABA esters (padimate O), cinnamates (cinoxate, ethylhexyl-p-methoxycinnamate), salicylates (octylsalicylate, homosalate), and anthranilates (methyl anthranilate). While these all block UVB radiation, the chemical group known as benzophenone (oxybenzone and dioxybenzone) provides protection against both UVA and UVB radiation. UVA is the most difficult to protect against.
Sunscreens have been assigned Sun Protection Factor (SPF) values by the U.S. Food and Drug Administration (FDA) since 1978. SPF is a number that refers to the sunscreen product’s ability to block UVB radiation and only some short UVA, but not long UVA. It is important to realize that the SPF numbers are calculated with an amount of sunscreen on skin that exceeds what most of us put on our own skin. The SPF is calculated with a quantity of 2mg. of sunscreen per centimetre2. Most people will put on about half to one quarter of this when used as sun protection. Unfortunately, low quantities of sunscreen of per centimtre2 will have minimal sun protective effects. Usually if 5mg. per cm.2 of sunscreen is applied to the skin, the sun protective factor is in the region of an SPF of 3. Sunscreen products with SPFs of two to 50 are currently available. A sunscreen product with a SPF of 15 will protect your skin 15 times longer from UVB than if you did not have sunscreen applied. The exact amount of time will vary from person to person, the altitude, and proximity to the equator. SPF 15 will block 95 percent of the UVB wavelengths. SPF 30 does not work twice as well. SPF 30 will provide another 3 percent of protection.
The efficacy of a product is related not only to its SPF but also to the ability of a sunscreen to remain effective under the stress of prolonged exercise, sweating, and swimming. The following three labeling recommendations have been suggested to help the ability of a sunscreen to remain effective:
- Sweat-resistant: protects up to 30 minutes of continuous heavy perspiration;
- Water-resistant: protects up to 40 minutes of continuous water exposure; and
- Waterproof: protects for up to 80 minutes of continuous water exposure. PABA and its esters demonstrate more resistance to sweating and/or water immersion than do other chemical sunscreens.
It is recommended that sunscreens be reapplied after swimming or perspiring. However, reapplication of a sunscreen does not further the period of protection. Sunscreen should be applied 20 to 30 minutes before sun exposure so the product has a chance to bond with the skin. Products containing PABA and PABA-like chemicals, however, may need to be applied up to two hours in advance of sun exposure in order to achieve their maximal effect.
All our sunscreens are water resistant, broad spectrum SPF30+ and contain moisturisers to help nourish the skin while protecting it. The individual’s skin type is an important factor that must be considered when attempting to choose a sunscreen with the appropriate SPF. In general, very fair-skinned individuals or those with previously sun-damaged skin may benefit from high SPF products. None of the available sunscreen products are recommended by the FDA for use on children under six months of age. In addition, products with an SPF of four or less are not recommended for use on children under two years of age because they will not provide adequate sun exposure protection.
Sunscreen Application and Selection:
- Before buying a sunscreen product, read the label and be sure that it will filter and absorb both UVA and UVB.
- Check also the products level of protection. SPF 15, or 30, depending on how long you usually stay out in the sun.
- Check the expiration date. An expired product will lose its potency thereby will not perform its role. This could lead to serious sun burn.
- Remember that lighter skin will burn more quickly than darker skin. Therefore light skinned individuals needs higher SPF.
- The product should comply and abide with the legal standards to support their claims and declaration for SPF, water resistance and board spectrum. This should be in their label.
- Check the products formulation. It must be non allergenic so it is safe to use on sensitive skin and on the face as well as nonacnegenic so as not to clog the pores.
- Insist on a product that is PABA free, containing no irritating chemicals and is safe to use on the face.
- Read the label and make sure that aside from sun protection, it also contains essential skin moisturizers to nourish your skin at the same time.
- Before applying a sunscreen, the skin should be clean and dry so that it can be well absorbed.
- Apply a liberal amount of sunscreen all over the body and pay special attention to the face, nose, ears, cheeks, and scalp as these are areas that are prone to sun burn.
- Reapply often, when perspiring heavily or after swimming. It is best to apply it fifteen minutes before you go out in the sun.
- Even on cloudy days, there is still a need for sunscreen application.
- Even with a sunscreen, avoid the sun during the hottest hours of the day starting at ten in the morning until four in the afternoon.
- Reflectors like zinc cream that reflects UV rays off the skin, should only be applied on small areas of the skin as they tend to limit perspiration.
No sunscreens should be used on children during the first six months of life. Sunscreens that contain aminobenzoic acid and its esters (PABA), cinnamates, and oxybenzone can cause a skin rash and allergic photosensitivities but this is uncommon. Miscellaneous compounds, such as fragrances, lanolin, alcohol, and preservatives may also cause skin and eye irritation or sensitization.
Symptoms are unlikely with normal childhood exposure. Stomach irritation and nausea are the most common symptoms. Since PABA sunscreens contain 50 percent or more ethanol, ethanol toxicity may be the greater risk. Many sunscreen products contain a form of an aspirin-like substance (salicylate) as their active ingredient. For example, homomenthyl salicylate (homosalate) is a sunscreen agent found in many Coppertone products. Theoretically, homosalate-containing sunscreens ingested in substantial amounts may cause aspirin (salicylate) poisoning; however, there are no such reported cases of salicylate intoxication.
Adverse reactions to sunscreens
Contact dermatitis, both irritant and allergic, and phototoxic and photo allergic reactions have been reported following the use of chemical sunscreens. The most common sunscreen that cause contact dermatitis is PABA and its esters. However, reactions to the newer generation sunscreens, especially those with broader spectrum of UV coverage such as benzophenones, cinnamates and methoxy dibenzoylmethane, have also been reported. Contact dermatitis and photoallergic contact dermatitis to different sunscreens can occur at the same time and should be explained by a combination of cross-reactions and coupling allergy.
Contact Suncare Solutions for more details about Sunscreens and Sun Protection Products or call 01292 5604888.