Nuffnang

Wednesday, June 30, 2010

Sunscreen ~ SPF vs UV

 We have seen SPF and PA+ on the sunscreen packaging but do you know what exactly do they mean?
The SPF (Sun Protection Factor) of a sunscreen is a laboratory measure of the effectiveness of sunscreen — the higher the SPF, the more protection a sunscreen offers against UV-B (the ultraviolet radiation that causes sunburn).

The SPF is the amount of UV radiation required to cause sunburn on skin with the sunscreen on, relative to the amount required without the sunscreen.So, wearing a sunscreen with SPF 50, your skin will not burn until it has been exposed to 50 times the amount of solar energy that would normally cause it to burn.

The amount of solar energy you are exposed to depends not only on the amount of time you spend in the sun, but also the time of day. This is because, during early morning and late afternoon, the sun's radiation must pass through more of the Earth's atmosphere before it gets to you. In practice, the protection from a particular sunscreen depends on factors such as:
  • The skin type of the user.
  • The amount applied and frequency of re-application.
  • Activities in which one engages (for example, swimming leads to a loss of sunscreen from the skin).
  • Amount of sunscreen the skin has absorbed.

Most people do not use sunscreen correctly, the amount of sunscreen applied, and the frequency of application in order to provide the skin sufficient protection and to help the skin revitalize, home intensive care like scrub and mask to help the skin condition improves and the skin complexion with translucence as melanin may deduce the activities of production. It is important to note that sunscreens can help reduce sunburn, they are not as effective against the other harmful effects of ultraviolet UV rays, such as premature aging of the skin and depression of the immune system unless they have the anti-aging essence ingredients in it. 




 It is important to apply sunscreen 30 minutes before you go under the sun.

UV A (Ultravoilet A)
Ultravoilet Rays A or UV A refers to long-wave solar rays that penetrates the skin deeply.
Causes sun damage penetrates the dermis layer and deeper connective tissue damage. By damaging the collagen and elastine in the dermis, skin loses moisture and elasticity, visible signs of aging such as wrinkles, premature aging and pigmentation. Skin can turn dark, red and aged even when the skin surface feels cool.
UV sunscreen face care about 4-8 of UV A protection which is adequate for normal daytime activities.
With SPF 24 , UV sunscreen face offer 95% protection against UV B.
PA (Protection grade of UV A)
95% of our daily UV exposure and has a strong penetration that can penetrates clouds and glass of 5cm thickness. Protection is also important indoors or while in the cars.
UV B (Ultravoilet B)
Ultraviolet Rays B or UV B refers to short wave solar rays that are basically responsible for turning the skin red or producing sunburns causes harm mainly to the epidermis layer (Outer) but its damaging effect is 1000 X stronger that UV A.
A short period of exposure can cause sun tan and inflammation and increase melanin production.
Sun very intense between 10am-3pm.
Strong reflection beware of the sun damage while out on the beach with brighter colour sand or ground.
Uses an umbrella or wear hats do helps to block against some reflection.


What is SPF?
SPF (Sun Protection Factor)
  SPF 1   = 20 minutes
  SPF 15 = 15 X 20 minutes = 300minutes that lasts for 5 hours
Avoid sun exposure between 10am-3pm (5 hours)
Block uses at SPF 15 or above UV PA ++

Japanese measurement of UVA protection:

PA (+) – Japanese measurement of UVA protection: PA stands for Protection grade of UVA. The PPD method with its classification PA+, PA++, PA+++ is popular all over Asia. [Chemistry Today]
PA+: some UVA protective effect. PPD 2-4
PA++: moderate UVA protective effect. PPD 4-8
PA+++: good UVA protective effect. PPD 8+ [Nora80]
PPD method 2-4 4-8 8+
Japanese PA method [Nora80] PA+ PA++ PA+++

PPD Method (Persistent Pigment Darkening Method)
Exposure to ultraviolet light or sunlight, the skin feels tired and sensitive, UVA or UVB, from sunlight accounts for 90% of the symptoms of premature skin aging including wrinkles. 
The most important skin-care product available to prevent wrinkles is sunscreen, but most people do not use sunscreen correctly, the amount of sunscreen applied, and the frequency of application in order to provide the skin sufficient protection and to help the skin revitalize, home intensive care like scrub and mask to soothe and lighten the complexion while mask do help nourishing the skin to help firming and the skin condition improves with visible fairness and translucence as melanin may deduce the activities of production. (copied & edited from Wikipedia.)

No comments:

Post a Comment

Please comment, thanks!