Are cyano glues safe?

We’ve received a letter from Dave Walters regarding the use of super glues/cyanoacrylates and a possible link to cyanide poisoning? Dave’s letter is below and we’d like to hear what you have to say on the subject and whether you’ve experienced similar difficulties.

I was modifying my plan-built Lazy Bee to add ailerons, and decided to add another spruce spar at the hinge line. I used my Dremel on high speed to cut through the hard part of the ribs where they had been glued with cyano and kicker accelerator. In some places, especially where the ribs had been capped with 1/16” balsa, I had to put a fair bit of pressure on the Dremel to bore through the solid glue build-up. I was surprised to see quite a lot of evil looking dense smoke emerge. I had my face close to the work so before I knew it I had breathed in a little of it, which was pretty unpleasant.

Some two hours later, after a couple of glasses of vino, I turned in. I was shocked to see my face in the bathroom mirror. It was pretty red, and I had two unusual bright red triangles under the bags of my eyes. My wife remarked that my ears were bright red too. But I felt OK. Good stuff, Rioja!

In the morning, we were talking about my clown like appearance, and she asked if it could have been connected to my glues. I used to do a lot of scuba diving, which included lectures on dive medicine and the effects of gases. I remembered the bit about the dangers of compressor exhaust wafting into the inlet and getting in the dive tanks, and the fact the carbon monoxide bonds readily to haemoglobin in the blood, reducing the vital flow of oxygen to all your bits. Carbon monoxide poisoning can be recognised by the fact that the victim has a bright cherry red appearance. I also remembered a debate about whether the cyano bit of the word cyanoacrylate meant that there was cyanide in the glue.

So I went on Google, and sure enough there was loads of stuff about the problems of cyanide release when cyano gets too hot such as when using a Dremel to bore through the stuff after it has set! I also discovered that cyanide makes oxygen stay in the blood rather than getting to your cells. So it works differently to carbon monoxide, but with the same result and your skin can become cherry-red! Sufferers can have general weakness, confusion, and bizarre behaviour, although that describes the normal me pretty well, so I did not notice anything else unusual.

Perhaps others, especially the chemists, medics, glue makers and glue users out there, can shed a bit more light on the subject. I have already had one other person say that they felt ill after a similar experience. In normal use, cyano seems safe. But is there a problem when it gets very hot?