Most Ca is 100% ethyl cyanoacrylate and the cured CA is waterproof but not solvent proof. Acetone and other industrial solvents will soften the cure of CA, breaking at least in part the stable nature of the CA.
When I was working with a series of sculptures in the late 1990's I was going through 6+ fl oz every day and I had started feeling dizzy...the Doctor said it was not the CA and that the worrisome element of CA being in the cyanide family was only an issue if the CA became vaporized, and then only to a small portion of the population 3-10% with flu like symptoms...CA vapors are absorbed upon contact with the wet surfaces of the nose, mouth, and throat becoming inert and eventually passed, voided, or sloughed. If a case of CA absorption in high amounts, like what I was dealing with, then if the person is not sensitive to CA it becomes a matter of body weight, health, etc.. Again the cyanide is a trace element in the case of CA so direct cyanide poisoning is not so much the issue...we build up and pass cyanide if in trace amounts.
I used some 2-octyl cyanoacrylate 2OCA (we called it Orca
but it was not any better or easier and was not as available.
I do not have your answer unfortunately...those people who chew on their pens take risks to be sure but those that are also actively smoking, drinking alcohol, or that are chewing high levels of chemicals like Nicorete or the like take even more of a risk as these can act as solvent sources.
So I do not have a better answer than cured CA is considered safe by the US and European health/toxicology safety programs. This is considering normal function and use of the given product...if this use defies the MSDS then it is what it is...CA MSDS (example)
http://www.sirchie.com/Assets/msds/cna102.pdf most note contact of ingestion as "Ingestion: Ingestion is not likely. See supplemental page." which is usually not supplied
So I think worst case is a loss of gloss as the mouth acid breaks the cured/polished shell.
Great question though :bananen_smilies104:
Raymond