UVA rays damage the skin (premature skin aging, some skin cancers) without tanning and without sun burning.
UVB rays are responsible for tanning and sun burns.
SPF (Sun Protection Factor) refers to the ability of a sunscreen to block UVB rays, but not UVA rays. The number doesn't indicate how long a person can be
outside in the sun before suffering from a sun burn, nor does it mean that twice the number equals twice the protection.
In other words, SPF 30 doesn't give twice the protection of SPF 15! See here what the numbers really mean:
SPF 15 blocks 94% of the UVB rays,
SPF 30 blocks 97% of the UVB rays,
SPF 50 blocks 98% of the UVB rays.
SPF 50+: The legislation of the European Community prohibits the indication of an SPF higher than 50. SPF 50+ indicates in reality an SPF of 60 and more.
PA is the Japanese way to indicate UVA protection and is used in most Asian countries: PA+: some UVA protection, PA++: moderate UVA protection, PA+++: good UVA protection. UVA in a circle: that's the regulation of the European Community and means that the UVA protection is at least a third of the UVB protection. There is no further graduation. The US label "Broad Spectrum" indicates that the product provides UVA protection that is proportional to its UVB protection.
Last modification: 01-02-18