He later explored other ways of killing that were less stressful for the Nazis.The gas van was one of them. Jews were forced into an airtight sealed truck and the exhaust gas from the trucks engine was lead into the truck resulting into the Jews being suffocated. This method was used to make the Nazis killing operations more effective (than by using the mass shootings). These gas vans were developed and run under supervision of the SS-Reichssicherheitshauptamt (Reich Main Security Office) and were used to kill about 500,000 people. The gas van had 2 main disadvantages: It was slow meaning that the victims took twenty minutes to die and it was noisy due to the drivers being able to hear the victims screams which they found disturbing and