What do SPF and PA mean?
K-LAB · 14 Tem 2026
The two abbreviations on a sunscreen label describe two different kinds of rays. Looking at only one of them can leave your skin aging and spotting while you think you are protected.
SPF: protection against UVB
SPF shows protection against UVB, the rays that cause sunburn. SPF 30 blocks about 97% of UVB rays and SPF 50 about 98%. The difference looks small, but noticeably fewer rays reach your skin. SPF 30 is the minimum for daily use; SPF 50 is recommended for long days outdoors.
PA: protection against UVA
The PA system was developed in Japan and rates protection against UVA, the rays that reach deeper skin layers, with plus signs: PA+ is the lowest and PA++++ the highest. UVA does not cause sunburn, but it passes through window glass and clouds and plays a major part in skin aging and dark spots. That is why Korean and Japanese sunscreens show a PA value; in Europe the same information is given by the UVA logo in a circle.
What does broad spectrum mean?
Broad spectrum means a product protects against both UVA and UVB. Beautyway UV Sun Cream and Natinda Daily Perfect Sun Cream protect against both with SPF 50+ and PA+++. Rivecowe BB Cream has SPF 43 PA+++; it is practical for everyday city use, but on the beach or on long days outdoors you need a separate sunscreen underneath.
The amount matters more than the number
The SPF on the label is measured in a lab with 2 mg of cream per square centimetre. In real life most people apply less than half of that and get far less protection than the label states. Aim for about two finger-lengths of cream for the face and neck. A high-SPF cream applied too thinly can protect less than a lower-SPF cream applied properly.
How often to reapply
Outdoors, every 2 hours, and straight after swimming, sweating or towelling off. If you stay indoors all day and do not sit by a window, your morning application is usually enough. To reapply over make-up, press the cream on with a sponge or use a cushion with sun protection.