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Carbon Monoxide from Melting Snow

A warning all hunters and campers should heed is to be extra a careful when melting snow over an open-flame cookstove. Such a seemingly innocent act may have been the cause of the death of Arctic explorers S.A. Andree and Knut Fraenkel. They died in 1897 on White Island, northeast of Spitsbergen. Thirty-three years later their bodies were found where the men apparently died while sitting comfortably in a warm tent. Aside from this conjecture about Andree and Fraenkel, there are known instances of serious carbon monoxide poisoning from open-flame campstoves in tents.

Tests have shown that the danger of poisoning is especially great when snow is being melted in pans placed on open-flame stoves such as the Primus-type and Coleman-type cookstoves. These tests were conducted in 1942 by a group that included two scientists well known in the North, Drs. Laurence Irving and Pete Scholander. Somehow in the years that have lapsed since 1942 the consequences of the tests seem to have been forgotten. Recently, the University of Alaska's Dr. Robert Elsner, who had participated in the tests as an experimental subject brought them again to light.

The essential problem involves the manner in which a stove operates. An efficient open flame campstove burns with a blue flame that is very hot, far above 1000°C (1800°F). In such a flame the combustion is complete So that the fuel is converted to safe carbon dioxide (CO 2 ). However if a cold object is placed in the flame, the flame is cooled to a yellow color and combustion is incomplete. The result is the production of carbon monoxide (CO), the deadly killer.

The tests of Irving, Scholander and others proved that the melting of ice or snow on open-flame stoves is especially dangerous. The reason, of course, is that the snow or ice keeps the pan cold until it is finally melted so that incomplete combustion is likely.

Tests made with rats in porous tents where cooking or snow melting was underway showed little or no carbon monoxide poisoning. But if the melting was done in an impervious tent or one iced over, serious poisoning resulted within a few minutes. Even in impervious tents that were somewhat ventilated, dangerous concentrations of carbon monoxide sometimes occurred.

The moral is obvious: be extra cautious when cooking in tents, snow igloos, or other tight shelters especially if melting snow or ice on an open flame stove. If a tent is made of porous material, make sure it has not become snow covered or been sealed by freezing rain. Extreme caution is called for if the tent is known to be impervious--occasional opening up of such a tent is not enough. Finally do not cook on a stove with a faulty flame, one that is irregular and partly yellow.