[nene]

I dont really wash my face before I go to bed, and I've been using facial moisturizer that has SPF 30, everyday in the morning before I go to work.
Some of my friends said I should really wash my face before going to bed because theres this chemical in lotion containing SPF that could cause cancer or whatever its just not good to stay in the skin.
But when I think about it again, no matter how clean you wash your face, if this chemical thing really exists, it will still build up slowly but surely in your skin... doesnt it?
I'm scared to use anything with SPF now....;_;

My skin's really important for me so I'm hoping to get a real, scientific answer if needed
Thanks in advance! =)

[Whateva]

Well SPF itself is a chemical. And leaving chemicals on your face too long will of course damage your skin. It's like staying out in the sun too long. It's common sense to wash your face before you go to bed...

[sayuri43]

The SPF 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 indicates the time a person can be exposed to sunlight before getting sunburn with a sunscreen applied relative to the time they can be exposed without sunscreen. For example, someone who would burn after 12 minutes in the sun would expect to burn after 2 hours (120 min) if protected by a sunscreen with SPF 10. 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.

credits: http://en.wikipedia.org/wiki/Sunscreen#Sun_protection_factor

but okay (if you've taken organic chemistry, you'll understand this part a little bit better... if not, ignore~~)
basically, sunscreen is made up of aromatic rings with carbonyls attached to it (benzoylbenzene), which "absorb" the UV radiation and "release" it at a lower energy (thus making it less harmful for our skin) but the thing is that these reactions form free radicals which are very reactive. So if you don't maintain the equilibrium by adding more sunscreen every couple of hours, there will be free radical reactions occurring on your face which are even more damaging (since you would be going from an incredibly high energy level to a much much lower one, there would be a lot of energy released in the exergonic reaction which woulld definitely have some effect on your face)


basically, sunscreen is made up of an organic compound and is a little dangerous to use and you should definitely be washing it off every day. I'm sure that it is water soluble, and the soap will help to get it off (er, I don't want to go on about the way soap works, but I'm pretty sure that it would work.... soap is a chemical compound too, you know)

[deportedkorean]

first off...i think not washing your face before you sleep is kind of gross...

...second, you should be washing your face at night no matter what you put on your face (even if you dont use makeup).

[Awkward Smile]

So if you don't maintain the equilibrium by adding more sunscreen every couple of hours, there will be free radical reactions occurring on your face which are even more damaging (since you would be going from an incredibly high energy level to a much much lower one, there would be a lot of energy released in the exergonic reaction which woulld definitely have some effect on your face)

But i wear makeup over my sunscreen, so i can't really reapply it every few hours.
If i stop wearing sunscreen completely, would it be more or less damaging than wearing it but not reapplying it?
=| i thought i was protecting my skin, argh!

[xchuchanx]

just apply SPF during the day, wash it off at night, and wear a non spf lotion at night.

prettyyyyy simple