Sunscreen products sold in Europe are covered by cosmetic products legislation. According to the regulations, sunscreen products should be labeled with certain symbols and specific labels to guide the user. It can be difficult to understand all the numbers, text and symbols on the sunscreen. Figure 2 gives a brief explanation of the most common labels.
Figur 2. An illustration of the most common labels seen on a sunscreen product. Each label is described in the following text.
Here is a brief explanation of the most common labels used in sunscreen products:
SPF stands for "Sun Protection Factor", i.e. protection against UVB radiation - the radiation that makes you tan. The number indicates how long you can stay in the sun without burning yourself compared to if you had not applied any sunscreen at all. In order to determine the SPF value of a product, tests on volunteers must be done. The test is performed by applying a standardized amount, 2 milligrams per square centimeter of the product to a certain area of the body on the test subjects. The product is then allowed to dry before radiating the skin with a UV lamp. The following day, the redness of the skin is assessed, and the effect of the test product is also compared to a standardized product along with skin that has not had any sunscreen applied. As mentioned earlier, you need to apply the product liberally. It is assumed that a person's skin is up to 2 square meters which corresponds to 40 g of cream (or other product) to correspond to the amount used in the tests. To make it easier for consumers, the SPF symbol must also be stated together with a rating: low, medium, high or very high. A summary of the sun protection factors that are allowed in Europe are displayed in Table 2. A product with SPF 50+ must at least grant SPF 55.
Table 2. SFP labeling on European products with the corresponding amount of UVB radiation that the product protects against and how much UVA protection the product gives least if it is labeled with a UVA symbol.
UVA - The UVA symbol may be used if the product's UVA protection makes up for amounts of at least 1/3 of the SPF value with which the product is labeled. UVA protection can be measured in vitro and thus does not require voluntary test subjects.
Water-resistance is measured by measuring SPF after the test subjects have been in a circulating water bath. The test is done by bathing for 20 minutes after applying the product, then waiting 15 minutes before bathing for another 20 minutes. If the product has at least 50% of its stated SPF value at this stage, the product is considered to be water-resistant. If the product holds at least 50% of its stated SPF value after four 20-minute baths with a 15-minute break in between each, the product is considered to be very water-resistant. In reality, you probably would dry yourself with a towel between the baths and thus remove some of the sunscreen, so it is always recommended to reapply the sunscreen after bathing.
PPD and PA are sometimes listed on products. PPD stands for Permanent Pigment Darkening and is a test that works like the SPF test, but where UVA radiation is measured. The test is performed on voluntary test subjects and the factor indicates how much longer it takes to darken the skin compared to when not using sunscreen. PA is the protective effect against UVA radiation and is a simplification of PPD. The scale goes from PA + to PA ++++.
A variety of tests are required to assure that sunscreen products work, and for many of them, voluntary test subjects are required, for instance when testing the SPF value of the product and testing water resistance. Even though the tests are controlled and voluntary, they always pose risks to the participants, since they are exposed to products which can cause allergic reactions. In addition, they are exposed to radiation that can cause skin diseases such as cancer.
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