The Truth About Sunscreen

What are sunscreens?
Sunscreens protect the skin from damage caused by ultraviolet (UV) radiation emitted by the sun. Traditionally they are a lotion or cream, but next generation products use convenient sprays to apply protection quickly and easily. Sunscreen active ingredients can be organic chemical absorbers (ex. Oxtinoxate or Avobenzone (Parsol® 1789)) and/or inorganic physical blockers (ex. Zinc Oxide or Titanium Dioxide). Sunscreens can help prevent sunburn caused by UVB rays and may reduce premature signs of aging.

Despite being very popular, they are still many myths surrounding sunscreens.

Myth: Sun Protection Factor (SPF) rating 60 will protect significantly more than an SPF 30.
Truth: SPF is a measure that refers only to duration of protection against UVB rays. The Sun Protection Factor SPF is the result of a biological procedure for measuring the effectiveness of UV protection products on human subjects against erythema (redness of the skin).

%UVB Absorbed (Sayre)
–((SPF-1)/SPF))*100

•SPF 2 absorbs 50%
•SPF 15 absorbs 93.3%
•SPF 30 absorbs 96.7%
•SPF 50 absorbs 98%
•SPF 60 absorbs 98.3%

In the United States there is currently no accepted rating system for protection against UVA radiation.

Myth: All sunscreens block some UVA.
Truth: Many sunscreens provide some UVA protection but to be a broad spectrum sunscreen that protection must be across the UVA range. Excessive exposure to UVA radiation is linked to premature aging and the occurrence of skin cancers like melanoma and basal cell carcinoma. Ingredients found in broad spectrum sunscreens include Avobenzone (Parsol® 1789), Ecamsule (Mexoryl®), Zinc Oxide, and Titanium Dioxide.

Myth: A high SPF sunscreen will protect me all day long with one application.
Truth: Research has shown that high SPF products can actual lead to changes in behavior that will result in a higher incidence of sunburn. Users mistakenly think a high SPF product will protect them all day with one application when in fact ALL sunscreens must be reapplied regularly regardless of SPF (even the labels on high SPF products advise users to reapply regularly). Common things like swimming/drying off, perspiration during activity and clothing (abrasion between skin and shirt collars, hat bands, wrist watches, sock cuffs, etc.) can all remove sunscreen – even a well-bonded sunscreen. Regular reapplication ensures the best results irrespective of the claimed SPF.

Myth: Some sunscreens are "no tears."
Truth: Eyes are not designed to allow foreign substances or materials in – although some formulas that use volatile silicones instead of alcohol may minimize potential irritation. All sunscreens contain ingredients which potentially could cause eye sensitivities. Eye irritation depends on the person and the circumstances.

Myth: Some sunscreens are waterproof or sweatproof.
Truth: The FDA has deemed the terms ‘waterproof’ and ‘sweatproof’ as misleading. The allowable description is ‘water-resistant’ to better reflect the reality that no topical product can be ‘waterproof’. Due to the fact human skin is designed to be ‘shed’ and sunscreen will be removed in this process. Water-resistant sunscreens use special ingredients to better bond to the skin and shed water better, but they still need to be reapplied regularly for best results.

Myth: Some sunscreens are actually sunblocks.
Truth: This is another term the FDA no longer allows as it creates the erroneous implication that a sunscreen can actually ‘block’ UV radiation. In fact, no sunscreens are complete UV blocks. All sun protection products allow some level of UVA and UVB radiation to penetrate the skin regardless of the claimed SPF level of protection.

Myth: Some sunscreens are ‘all-natural’ or ‘organic’.
Truth: There are actually several ‘all-natural’ sunscreens (ex. clay, hippopotamus sweat, coral amino acids, etc.). However, the FDA only permits 16 active ingredients in products claiming to be a sunscreen (‘legal’ sunscreens are drug products and are made to very strict pharmaceutical standards) and all require some degree of purification or manufacture and therefore do not meet the criteria of an ‘all natural’ ingredient. There are numerous ‘illegal’ sunscreens marketed in the United States, but these products are not legally able to make SPF claims nor have they met any of the quality standards required in an approved product. Consumers need to be very wary of these ‘black market’ sunscreens making outlandish claims.

The term ‘organic’ is also misused and since it is unregulated when it comes to topical drugs and cosmetics there is no uniformity among products making this claim. In food products, ‘organic’ is a term applied to foods with at least 70% certified organic content and this is governed by various bodies, including the FDA. There is no organic certification for sunscreens. . If a sunscreen were truly ‘organic’ in a food sense, it would require an aggressive preservative system or refrigeration. To make matters even more confusing, ‘organic’ in a chemical sense refers to the presence of carbon and hydrogen molecules – which is a given with current UV absorber ingredients (making almost all sunscreens ‘organic’ in that sense). Inorganic minerals like Zinc Oxide or Titanium Dioxide as the exclusive UV screen are possible, but to be effective they must be present in very high concentrations and this creates a very white cream or lotion that looks like white paint on the skin. The best combination of the intent of these terms is a sunscreen with some organic active ingredients (using a combination of the 16 approved actives) in an inorganic base that does not require a preservative system. The cosmetic silicone cyclomethicone is an ideal base in this sense because it does not promote bacterial growth and does not have the drying and potential for skin irritation of a base like ethyl alcohol (SD-40 alcohol) - commonly used in the new propellant-based sprays.