1 post tagged “pdd”

With the weather warming up quickly in California, I thought I would elaborate a little more on my thoughts about sunscreen.  I am not an expert, but i have been around more than a couple skincare forums for a few years now, and I have researched the matter to some degree.  

When choosing sunscreen, it's important not only to pay attention to the level of UVB protection which rated is by the "SPF" of a sunscreen but the UVA level also.   While UVB rays are rays that burn and tan the skin (UVB = Burning rays), UVA rays are the ones that penetrate the deepest and cause aging of the skin (UVA = Aging rays).  Most sunscreens only list the SPF of the product while entirely neglecting the UVA rating.  As of now, there is no american rating system but one way that UVA is rated is through PDD (Persistent Pigment Darkening). 

Most sunscreens on the market offer exceeding low UVA protection.  For a quite a few years, I was content wearing Japanese sunscreen thinking i was getting some sort of total protection since i was using an SPF 55.  When i found out about PDD, I was horrified.  I also discovered that most asian sunscreens offer a PPD 8, which is really low in comparison to some European sunscreens which reach as high as PDD 35. 

Then there came another question for me, one i never considered before--chemical sunscreens versus physical sunscreens.  physical sunscreens are made from filters such as zinc oxide and titanium dioxide, while chemical filters include but are not limited to avobenzene, oxybenzone, and meroxyl.  chemical sunscreens absorb uv rays and need to be applied 20 minutes before sun exposure so that the chemicals are properly absorbed into the skin.  physical sunscreens deflect and absorb uv rays. 

a lot of sunscreens will be hybrid of physical and chemical filters. among the members of the skin forums i frequented, there was a strong belief that only chemical sunscreens would ever offer a high enough PDD and most if not all of these sunscreens, would be European.  I quickly jumped on the wagon and purchased La Roche Posay Anthelios Fluide Extreme SPF 60, PDD 28.  After using this for a whole summer, I first saw pigmentation in the form of really light freckles.  I posted on my forum and discovered that there were others who made the change to these euro SS and had also experienced a spike in their pigmentation.  I think more research caused me to believe in physical sunscreens.  now, there is still a strong following for the euro SS, but i have chosen to go with physical filters which also coincides with my goal of using more natural skin care products. 

some things to be aware of:  certain skin care products/ingredients will make the skin more photosensitive.  these include but are not limited to:

1)  retinoids -  which are potent ingredients, proven to reverse signs of wrinkles, pigmentation.  but be warned that these thin the epidermis, and not using proper sun protection and avoidance will cause the reverse effect - even more pigmentation and wrinkles.  so it is usually advisable to use products containing this ingredient at night time.  

2)  AHA/BHA - these acids resurface the skin also, though not a deep level like retinoids. 

3)  microfiber cloths - this is purely my personal opinion

4)  certain essential oils will cause sun sensitivity.  i have read and Li has told me it is the expressed forms of many citrus EOs. 

personally, i never use any exfoliants in the morning.  i believe the skin has to be "whole" in order to fend against UV rays we are bombarded with everyday. 

also be aware that the chemical filter, avobenzene (parasol 1789) will degrade the protection of a sunscreen when used in conjunction with mineral makeup.  i don't know the exact specifics but there are various sources online discussing this issue.

Again, i am not an expert, but this is what i know or as much as i can articulate into words for now.  Here are some excellent online sources to help further your knowledge about sunscreen:

http://makeupalley.com/user/notepad/sunscreenFAQ/

http://www.makeupalley.com/user/notepad/sunscreens

http://www.skincarecentral.biz/sunscreens-about-.html