"Will heated copper pipe emit cyanide gas?"

A. Hi Anthony. The water you are heating can never exceed 212 °F, so that can't be an issue; and the pipe can never get much hotter than that as long as it is full of water. But whether your rocket stove will generate enough heat to make the copper get too soft or too hard for your purposes when it's dry, I'm not sure. Make sure it always has water in it while heated.

Luck & Regards,

A. There are some myths going around about copper, and they stem from the fact that copper pots and pans are usually coated with tin. I studied some Chemistry in college, but my degree was in Geology.
Copper as far as I know is a native element. Minerals that are composed of atoms from a single element are referred to as native elements. The minerals in the gold group all occur together in the periodic table of elements and have a common crystal structure. They all are soft, can be hammered out into thin sheets (malleable), drawn into wire (ductile), and cut into thin shavings with a knife (sectile).
Adults have 50 and 80 milligrams (mg) of copper in their body, mostly in muscle and the liver. Copper helps make melanin, bone, and connective tissue.

The main reason copper pots and pans are coated, most commonly with tin, is that copper is a reactive substance. But it's not the heat that causes problems it's the reaction with highly acidic foods like vinegar and tomatoes, which can cause copper into the food creating an imbalance in your body which can cause toxicity. Meaning too much copper in your system, since its a native element by itself cannot be harmful unless you reach excessive levels. The same reason Gold, Silver, etc., are used as fillings because you cannot be allergic to native elements.
The problem exist when copper is manufactured it is usually no longer pure. It is mixed with other elements, which is why people will sometimes have a reaction to surgical steel plates etc. Even though they tell you you can't be allergic to it, they are wrong. It's the other small percentage of elements that cause the allergy.

In essence the West, in general, is where most copper toxicity is found and can cause mental heath issues. This can be attributed to copper usage being much higher here is these states. But heating copper alone produces nothing, heating excessively in air produces copper oxide which will cause a black coating and overheating it can cause the release of Cu2, Most unlikely to occur from using a cooking pan.

A. No, but where did you come up with that theory?

A. Like Ted, I am wondering how a college chemistry student came to be concerned with whether a heated copper (Cu) pipe could release cyanide (CN) gas.

Chris Jurey, Past-President IHAA
Luke Engineering & Mfg. Co. Inc.

Wadsworth, Ohio

A. Hi. Copper generates nothing toxic that I've heard of, not does iron pipe. I use both cast iron and copper-bottom pans on my kitchen stove burners all the time.

Regards,