Paul and everyone

Ketones, of which acetone is part of that group, are by their nature are rapidly taken up by the body in solution.

But first, the MSDS is by law to contain certain specific information. That information it contains is definite, "morgue technique" information. In other words, epidemiological investigation conclusively demonstrates an effect, or that NIOSH or others is about to state a definite effect. By law MSDS must be updated to stay current to the science. It's designed to be a layman worker's guide to the chemical and is not the definitive document. In other words, the MSDS contains the very minimum in order to comply to OSHA standards for the Worker's Right To Know Act. You should be aware of legal fallout if the industry allows for an MSDS on acetone to talk about respiratory depression, or liver disfunction, bone marrow effects, neurological effects, and suspected mutagenic, terragenic and cacinogenic effects. To do so clears the way for many a lawsuit. Everyone was awash in the stuff.

Now, if you were to do a literature search you'll be wearing your gloves, and not latex, but heavy nitrile rubber or vinyl gloves, and in a well ventilated area. Nick not many weeks back made a comment on vinegar as a solvent issue for epoxy. He almost had it right, but ascetic acid is not a threat, we eat it. What he probably meant or heard was that constituents in resin and hardeners are carried into the dermal and subdermal tissues, and thus, is rapidly taken up by the body. He's right of course.

Also, OSHA has established limits on acetone: 250 ppm Time Weighted Average (TWA). Here's a link to "the rap sheet"
http://www.cdc.gov/niosh/idlh/67641.html

Acetone is regulated under the Toxic Substances Control Act (TSCA).

Under EPA's IRIS, this link is an interesting read, too:
http://www.epa.gov/NCEA/pdfs/acetone/ToxRev.pdf

Paul, since you're in San Diego, head on over to UCSD medical library and do a literature search. You'll develop a very healthy respect for the ketones.

For further information, vist http://www.cdc.gov/niosh/homepage.html.