Sunscreen and UV Protection – PA, SPF or UVA: Summer is scorching hot, so we need to put on a good sunscreen protection to protect our skin from sunburn – but with hundred kinds of cream available in the market, with packaging ranging on a variety of English abbreviated indicators, such as SPF, PA, UVA, UVB, what do they mean – Below is a description of SPF, PA, UVA, UVB, and how to choose sunscreen products.
4 Common Indicators of Sunscreen Lotion
UV is an abbreviation for Ultraviolet Light. It can be roughly divided into UVC, UVB, UVA by wavelength. We are not vulnerable to UVC radiation, but the longer wavelengths of UVA and UVB can directly damage our skin, causing aging or even skin cancer in addition to redness, darkening or sunburn. Here are the four most common sunscreen product indicators and their meanings:
UVA (Ultraviolet Radiation A)
Approximately 95% of UVA reach the surface of the Earth, with high penetration due to long wavelengths and direct access to the dermis. UVA is the main cause of skin tanning, wrinkles and aging. It also increases the risk of skin cancer.
UVB (Ultraviolet Radiation B)
Although the wavelength and penetration are less than that of UVA, it can only reach the epidermis, but the energy is stronger than UVA. UVB can make our skin red and cause sunburn. It also causes skin aging and increase the risk of skin cancer.
SPF (Sun Protection Factor)
SPF known as the Sun Protection Factor, is the UVB sunscreen protector. It can protect your skin from being sunburnt for a certain period of time. Simply put, a product with a higher SPF value can delay your skin from sunburn.
PA (Protection Grade of UVA rays)
PA is in regards to the standard of UVA defenses. Sunscreen generally indicates the strength of the defenses with + (PLUS) sign. The more + there are, the better the protection against UVA (e.g PA++++). This is the measurement method used in Japan, mainly according to the PPD (Persistent Pigment Darkening) index for sunscreen.
How to choose the right Sunscreen?
Nearly all sunscreen products can block UVA and UVB, but there are no sunscreen products that can completely block light damage, and the U.S. Food and Drug Administration (FDA) requires that any Sunscreen products below SPF15 should be added on the packaging only to protect against sunburn, not to prevent skin aging or skin cancer. Some people may feel that the higher SPF is better, but the higher the SPF, the thicker the texture would be, making it difficult for the skin to breathe, resulting in acne, allergies and other problems.
According to Dr. Colette Pameijer, an American surgical oncologist, it is usually best to use sunscreen of at least SPF30, but not to exceed SPF55. Compared to choosing high SPF products, it is better to pay attention to the multiple replenishment of sunscreen, it is best to use sunscreen 15 minutes before going out, once every 2 hours. You need to reapply it if you sweat or swim frequently, in order to get the optimal sun protection.