The page to which I linked is not the manufacturer's homepage, but rather a page discussing similar machines. (It does have a picture quite similar to the specific machine about which was asked.) Apparently they have uses at Halloween and other outdoor/indoor functions. It emits tiny bubbles (tiny like in a foam, but fairly separated) which apparently look reminiscent of snow as they fall. Either way, the page is a nice reference for this particular type of machine. (The site itself is a nice reference for Halloween mechanations in general as well.)
Chauvet's website (**broken link removed**) has the manual for the machine and by clicking on the snow fluid you can find the link to the material safety data sheet in Microsoft Word format. Other than the fact that Chauvet's machine looks strikingly similar to the one pictured at the bottom of the page to which I linked, a quick perusal of the short manual and the material safety data sheet will confirm it to work similarly.