So what does "SPF" and "PA" means on sunscreen?
SPF: Protection against UV-B rays. Increases the time before skin starts burning.
SPF 1 protects skin against UV-B rays for 15-20 minutes
PA: Protection against UV-A rays. Increases the time before skin starts darkening.
PA+ can increase the time before skin starts darkening by 2-4 times. PA++ increases the time by 4-8 times. PA+++ is the maximum protection and can increase the time by more than 8 times.
For people who are indoors most of the time, you can choose sunscreen products with lower SPF index, e.g. SPF 30 with PA +++, which gives you enough protection without taxing your skin.
For people who are outdoors most of the time, you can choose sunscreen products with higher SPF index, e.g. SPF 50 with PA +++, which is sweat and water resistant to give maximum protection.
Below are example of some sunscreens which are available in Singapore.
From left to right (1. Shu Uemura UV Armor SPF 30 PA +
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