Are UV Films for Windows Really Effective in Blocking UV Rays?

[Solid Snake]

Hey everyone. Just a basic question out of curiosity. How effective are UV films for windows for blocking UV rays? Every window film I see says it blocks 99% of UV rays. I just put them in my house, and honestly, I find it hard to believe that it is blocking 99% of UV rays (that being rays from 400nm downward). I swore a long time ago I saw a news report that says that they don't really work well. I looked for it online and can't find anything. I personally want protection from UVA and UVB rays for my skin and furniture while in my house, so this is of some importance to me.

So do these films really block 99% of UV rays?

 

[256bits]

http://cool.conservation-us.org/waac/wn/wn30/wn30-2/wn30-204.pdf

That is from the Winterthur Museum
http://www.winterthur.org/?p=174
which you can imagine, would want to protect their poop, er exhibits, from aging from sunlight.

 

[Vagn]

Window glass (typically float-grown soda lime glass) on it's own would prevent transmission of UV-B wavelengths and lower. See the transmission spectrum in slide 20 http://www.iop.org/events/scientific/conferences/y/09/energy/file_44016.pdf.