Exhaust gas gas is undesirable, noxious, or toxic substances, such as carbon monoxide (CO) from incomplete combustion, hydrocarbons (properly indicated as CH, but typically shown simply as "HC" on emissions-test slips) from unburnt fuel, nitrogen oxides (NO) from excessive combustion temperatures, and particulate matter (mostly soot). Exhaust gas temperature (EGT) is important to the functioning of the catalytic converter of an internal combustion engine. It may be measured by an exhaust gas temperature gauge. EGT is also a measure of engine health in gas-turbine engines (see below). During the first two minutes after starting the engine of a car that has not
Gas chamber extermination camps at Bełżec, Sobibór, and Treblinka used exhaust fumes from stationary diesel engines. In search of more efficient killing methods, the Nazis experimented with using the hydrogen cyanide-based fumigant Zyklon B at the Auschwitz concentration camp. This method was adopted for mass killings at the Auschwitz and Majdanek camps. Up to 6000 victims were gassed with Zyklon-B each day at Auschwitz. Most extermination camp gas chambers were dismantled or destroyed in the last months of the World War II as Soviet troops approached, except for those at Dachau, Sachsenhausen and Majdanek. One destroyed gas chamber at Auschwitz was reconstructed