HydrocarbonsTotal hydrocarbons, measured as methane, are typically measured in the source gas manufacturing process. Hydrocarbon content is of interest in oxygen, nitrogen, and argon manufacturing due to the natural presence of these compounds in the atmosphere. In carbon dioxide manufacturing, the source gases for these processes may have high hydrocarbon content. The gas manufacturing purification processes are efficient and the typical total hydrocarbon levels are stated in Table 3.6.