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Good information to have with regard to HCN exposure

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Great! Thanks Brent
Kevin and Brent,
Thanks for the information . Southern Maine EMS is coming out with Hydrogen Cyanide poisoning protocols and I'll pass these links on to our medical director to see if they can be of assistance. One thing I was wondering about was the protection level provided by turn out gear against absorbtion. Considering the make up of smoke includes droplets of liquid and possibly suspended liquified Hydrogen Cyanide, is absorbtion a factor in exposure in a fire situation?
I agree, good answer Brent.

Brent and Chris:
I am having trouble sending, and posting on the page, a good reference document to have about CN.
Could you email me directly?
Last year 44 pigs died as a result of manure gasses that were released when liquid food was spilled in the manure cellar under the pig stables.

Fire fighters being called in measured not only H2S but also HCN. As a result they decided to enter the stable only in gas tight suits. Luckily before doing this, they put a ventilator in front of the stable door. This probably saved the lives of the pigs that had survived till then.

I am still trying to find out if it was really HCN they measured, or if it was cross sensitivity of their electrochemical cell and Dräger tube for H2S. Both ARE cross sensitive, as I have tested too. However, this makes it unclear if there was or was not any HCN gas in the stable.

Apart from this yes or no question, I am looking for info on the risks of skin permeation by HCN gas. I know that inhalation of the gas is the biggest hazard, but as HCN (in liquid form) can enter through the skin, I am looking for info of the danger of HCN GAS and permeation of the skin. Untill now I have not been able to find any info on this. In a stable incident like this I would have no hesitation to enter with normal PPE. In case of an accident in an indoors industrial incident with pure HCN gas I would not do that.
Hope you can help!
Your on the right track with the cross sensitivity issue.
The next step would be to find out the cross sensitivity +/- ppm for both gases' sensors and deduct the difference. From the description of the incident it sounds like H2S is the culprit here.

As far as absorption HCN is concerned, I am not sure. If you find out anything please let me know.

For more information about HCN go to :

Thanks. Kevin Reilly
Hi Kevin,

It is too uncertain to base any decision on deduction of differences in case of the presence of both H2S and possibly HCN. That is why our national environmental institute has been given the order to search for another simple detection method for HCN that can be used by firefighters in the field. I will keep you informed!



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