what chemical if ingested causes the body to produce toxic gases to be excreted?

Question

My first aid class was asking and I couldnt tell them. I know this can happen but I dont know what sort of poisoning can produce the effect whereby the body becomes lethal to others

Answer 1

Well, that's sort of extreme, but, maybe if someone ingests an important amount of a cyanide, such as sodium or potassium cyanide, it will react with the acid in the stomach and (in addition to death to the poor guy who ingests it) will produce hydrogen cyanide - a toxic and possibly lethal gas to whoever breathes nearby. Same could happen with certain sulfides, but maybe to a lesser extent, such as sodium sulfide and sodium bi-sulfide. The acid reaction in the stomach will generate hydrogen sulfide, also poisonous to whom would attempt to give mouth to mouth breathing (Hydrogen has an extremely pungent and repulsive odour, so it is unlikely someone would attempt it). There is another case, if the person ingest some hydrogen generator such as zinc powder and then an arsenic compound. Inside the stomach the reaction will yield arsine, very toxic.

These cases are too weird, not likely to occur, normally the person would not able to ingest such amount of poisonous substance because first falls in a terrible state of pain and desperation, unable to think consciously. Of course there are methods, but I would not mention them here.

In literature and history, there is a tendency to consider assassination or self-termination (Suicide) using such chemicals, a romantic, pacific and venerable act. Nothing to do with real life. I always say to my chemical safety clients that if someone has the stupid idea of commiting suicide, it would be better search something else like self- shoting on the head or jumping onto a high speed truck, because most chemicals will not kill you (At least not instantly) but after a long, long, long time of terrible and indescriptible pain and desperation, rolling and tumbling in the floor screaming, releasing sphincters and all the stuff. Not very romantic, right?