<html> <body> The following is quoted from the excellent source cited by John Delmore: <blockquote type=cite class=cite cite="">A number of studies, both case reports and workplace surveys, have been reported in which occurrences of asthma have been linked with exposure to ECA and/or MCA. In many bronchial challenge tests, it seems that the challenge concentrations involved were directly irritant. Hence, it cannot be judged whether the mechanism of the observed bronchoconstrictive effects is allergic or irritative; in many cases, the responses seen can be attributed to irritant effects exacerbating a pre-existing asthmatic condition (or one induced by some agent other than MCA/ECA). </blockquote> <a href="http://www.inchem.org/documents/cicads/cicads/cicad36.htm#11.1" eudora="autourl"> http://www.inchem.org/documents/cicads/cicads/cicad36.htm#11.1 </a>It also says: <blockquote type=cite class=cite cite="">There are no useful carcinogenicity or reproductive toxicity data available. </blockquote> The question as to whether the material is toxic, as opposed to an irritant or an allergen is somewhat academic.  If you experience symptoms, you know you need to take protective measures.  If you don't experience symptoms, you still need to do so.  One problem, of course, occurs when the exposure limit is lower than the odor threshold, that is, by the time you smell it, you're overexposed.  MSDS's should have that info.  With regard to the UFO version of the Satellite City brand of CA glue, my inquiries, after my own experience last summer, provided the explanation that the molecular weight is heavier, which makes the fumes heavier and tend to settle away from the face.  This is all fine, however, if the material is used in an enclosed space, and the air is stirred, either by fan or by other movement, the beneficial effects are mitigated.  Respirators must fit properly (sorry, no facial hair allowed) and can create their own respiratory distress, in the increased resistance to air flow. IMO The only really safe (for you and the customer) way to use this "stuff  in extended application is to insure sufficient air exchange. The again, there's Marcel : <blockquote type=cite class=cite cite=""> sometimes a man's got to do what a man's got to do. Marcel Carey</blockquote> So, to quote from  O Brother, Where Art Thou,  "I'm with you fellers". David Skolnik <blockquote type=cite class=cite cite="">  <a href="http://www.inchem.org/documents/cicads/cicads/cicad36.htm#9.2.2" eudora="autourl"> http://www.inchem.org/documents/cicads/cicads/cicad36.htm#9.2.2</a> The cure time is indeed controlled by the acid content.  The polymerization is initiated by a base, and terminated by an acid (water can act as both), so the more acid you have, the shorter the polymer chains, and the longer it takes to get all the monomers involved. Accelerators contain much nastier fumes than the actual CA.  CA is an irritant, but in accidents where people got it in their eyes, even, there was no lasting damage reported.  There have been reports of people being sensitized to CA, to the point that they could no longer use it, but this seems to be pretty rare. Hope this helps, sorry to sound so scientific, but I AM a chemist!! :-) John -- Either way, it seems to me that the fumes are irritating and noxious, but so far I'm not seeing info stating that they're toxic. Can anyone point to something definitive that says CA fumes are toxic? Thanks. -Mark Schecter > > <a href="http://www.ca-plus.com/faq.html" eudora="autourl"> http://www.ca-plus.com/faq.html</a></blockquote></body> </html>