I suppose it should not surprise me to find people who are unfamiliar with this issue.  The popularity and growth of these forums almost guarantee there will be someone reading who does not know of the danger of using PVC with compressed air.  It's just that for those of us who are "regulars" this is such a well known topic we feel like we're beating on the same old dead horse again.

Let me suggest this to those unfamiliar with this ongoing discussion.  Go to the top of the page and click search.  Search for the subject PVC air and select the last year for a time frame. If that creates more responses than you wish to read through search again but filter by author Mike SE IL  That should get it down to about 3 hits.

If after reading up on it you want to tell me, Mark, and others how **** dumb we are, that you have used it for years with no problem, save your efforts.  You are wrong. Period.  End of discussion.  If you have never heard of or considered the subject, we welcome you to do some research because the danger is very real and the results may be very catastrophic.

edit: Here are a few other sources to ponder on:

http://www.osha.gov/dts/hib/hib_data/hib19880520.html

http://www.garagejournal.com/forum/showthread.php?t=60109

http://www.eng-tips.com/viewthread.cfm?qid=122826

http://www.hotrodders.com/forum/pvc-air-lines-108824.html