superglue burning eyes

[John Delmore]

Cyanoacrylates in general have very low toxicity.  There are no
"side-reactions" in the polymerization that would lead to toxic fumes.  The
vapor pressure is pretty low, less than 2mm Hg, so you're not going to get
much alkyl cyanoacrylate vapor ("whole" CA vapor).  One thing that may be
bothersome is ammonia produced when the polymers crosslink with each other.
Aldehydes (formaldehyde for MCA, acetaldehyde for ECA, butyraldehyde for
BCA--these are all major health concerns) would only form on hydrolytic
degradation, as stated before, not during the actual "curing".  Anyone who
can bear the scientific gobblydegook can find a wealth of info here

  http://www.inchem.org/documents/cicads/cicads/cicad36.htm#9.2.2

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

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Mark Schecter
Sent: Friday, April 28, 2006 12:40 AM
To: Pianotech
Subject: Re: RE : superglue burning eyes

Hi, Don.

I admit it had occurred to me to wonder, what with "cyano-" in the name,
but clearly it's not cyanide. Interestingly, if you Google
"cyanoacrylate fumes" you get a bunch of sites related to using fumes
from _heated_ CA to react with fingerprint oils in forensics. CA boils
at about 150°F. What I'm wondering now is, when we use CA cold in
pianos, are the fumes we smell whole CA vapors, or are they some
component/solvent/fraction? One thing I read said that the cure speed is
controlled by the acid content, i.e. more acid cures more slowly. That's
the flip side of a base such as baking soda or even water acting as an
accelerant. Seems to me the irritating fumes may be, at least in part,
acid fumes.

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

Don wrote:
> Hi Mark,
> 
> You may well be right.  Here is a less technical description that clearly
> states it is not cyanide.
> 
> http://www.ca-plus.com/faq.html