Topic: OMG RepRapper's vapor smoother catches fire!
And makes a pretty flame-
http://www.youtube.com/watch?feature=pl … JWhfpWlGFg
They ignited a jar of acetone vapor to show what happens, and it turned into a big sterno can, little more than the flambe typically done for restaurant guests. There is only a small amount of acetone in the bottom, and only the top of the vapor can mix with oxygen. I still recommend using it outside, so if any vapor spills it isn't likely to get into trouble anywhere.
As for the health risks, here is what Wikipedia says-
EPA EPCRA Delisting (1995). EPA removed acetone from the list of “toxic chemicals” maintained under Section 313 of the Emergency Planning and Community Right to Know Act (EPCRA). In making that decision, EPA conducted an extensive review of the available toxicity data on acetone and found that acetone "exhibits acute toxicity only at levels that greatly exceed releases and resultant exposures", and further that acetone "exhibits low toxicity in chronic studies".
http://blog.reprap.org/ They use a glass jar heated up on the printer's heated platform. It wouldn't fit very well in a Solidoodle.