不同指数的霜能防多长时间

防晒指数：

SPF值越高，对于UVB防晒的防护效果越长，越慢被晒伤。 PA(或称PFA)值代表防御UVA紫外线能力，PA以加号(+)代表防御能力，3个加号(+)为{zg}指标。

PA值与防晒时间关系表

1.PA(PFA)：PA+
抵抗时间：抗UVA约2 ~ 4小时
代表意义：对UVA有轻度防护力

2.PA(PFA)： PA++
抵抗时间：抗UVA约4 ~ 8小时对UVA
代表意义：有中度防护力

3.PA(PFA)：PA+++
抵抗时间：抗UVA约8小时以上
代表意义：对UVA有高度防护力

供参考防晒指数列表：

搭公车、地铁上下班：中午外出用餐记得携带防晒用具并使用SPF15-20PA+以上

座位不靠窗的上班族：SPF15-20PA+以上

座位靠窗的上班族：SPF30 PA++以上

百货公司逛街：SPF15-20PA+以上

路上逛街：SPF30PA++以上

室外活动超过3小时：SPF40PA+++以上

海滩、山上：SPF50PA+++以上

重视美白/健康肌肤：SPF30PA+++以上

The anti-sunburning frost being unlike an exponent can defend against how longtime

Anti-sunburning exponent:

SPF value is being got long , increasingly slow as being taller than, to anti-sunburning UVB protection effect more by bark scorch. PA (or the name PFA) value representative defense the UVA ultraviolet ray ability , PA takes that the plus sign (+) representative defense the ability , 3 plus signs (+) as maximal index.

PA value and anti-sunburning time concern a form

1. PA (PFA): Time PA +
is fought against:
Resist UVA about 2 ~ 4
hours of representative
significance: Have
boundary light to UVA
protecting a force

2. PA (PFA): Time PA + +
is fought against:
Resist UVA about 4 ~ 8
hours of pair of UVA
representative
significance: Have
middle to protect a
force degree

3. PA (PFA): Time PA + +
+ is fought against:
Resist to represent
significance above UVA
about 8 hour: Have
altitude to protect a
force to UVA

Anti-sunburning exponent of confession reference listing:

The public vehicle , subway numerous and repeated are on or off duty: Above going out and have a meal keeping the anti-sunburning appliance of carry-over in memory and using SPF15-20PA + at the noon

The seat does not depend on the window working race: Above SPF15-20PA +

The seat depends on the window working race: Above SPF30 PA + +

The department store strolls around the street: Above SPF15-20PA +

Stroll around the street on the way: Above SPF30PA + +

Outdoor activities exceeds 3 hours: Above SPF40PA + + +

Beach , Shan Shang: Above SPF50PA + + +

Take white beautiful/ healthy skin seriously: Above SPF30PA + + +