The days are longer and the nights are shorter and the scorching heat of the sun is evident. It only means one thing—summer. And to complete your summer starter pack, a sunscreen is a must.
Sunscreen, sunblock or suntan may be presented in a form of gel, spray or most commonly as lotion. The purpose of using sunscreen is to inhibit, if not limit, the harmful effect of direct sunlight which may cause permanent skin damage or worse, skin cancer. How do we measure the efficacy of these topical products with regard to their “sun-blocking” abilities?
Alphabets of SPF and PA
SPF or Sun Protection Factor determines the efficacy of the sunscreen to protect the skin from UVB rays which can cause sunburn, skin damage, and can contribute to the development of skin cancer. According to Dr. Heather Brannon, SPF rating tells you how long you can stay in the sun without getting burned while wearing sunscreen, compared to how long you can stay in the sun before you burn without wearing that sunscreen. A higher SPF doesn't indicate superior sun protection. An SPF 2 protects your skin just as effectively as an SPF 30. "However, an SPF 2 will need to be applied more frequently because it's only doubling the amount of time you can stay in the sun before burning. However, both SPF 2 and SPF 30 need to be thoroughly applied and reapplied when the protection timeframe runs out and after swimming or sweating", added Dr. Brannon.
Blocks 93% of UBV rays
Blocks 97% of UBV rays
Blocks 98% of UBV rays
On the other hand, PA or Protection Grade of UVA indicates the level of protection against UVA rays. UVA, which causes skin aging, wrinkles and also contributes and initiates skin cancer, penetrates deeply into the skin compare to UVB. The PA system is the Japanese measurement of sun protection which is based on the Persistent Pigment Darkening (PPD) reaction reading at 2 to 4 hours of sun exposure.
Provides some UVA protection with a factor of PPD 2-4. It protects sensitive skin against low to medium UV radiation.
Provides moderate UVA protection with a factor of PPD 4-8. It offers better protection from UVA rays and can be used by people with normal skin exposed to medium UV radiation.
Provides good UVA protection with a factor of PPD > 8. It is the strongest grade of UVA protection now available. It is designed for normal skin under very strong or direct UV radiation.
When picking the suitable sunblock for your personal use, choose a product with a broad-spectrum formula and it is important to reapply it every few hours. SPF 30 with PA+++ is recommended for daily use, while SPF 50 with PA+++ is advised if you are about to engage to outdoor activities and for people living nearer to the equator. Also, take into consideration your hiyang factor to a certain product for some ingredients might cause allergy or breakouts to your skin.