Typical oil vapor levels reported for breathing air include gaseous hydrocarbons with up to ten carbons (C1-10). ISO 8573-1:2010 [34] defines oil to be a mixture of hydrocarbons composed of six or more carbon atoms (C6+). Method of collection varies depending on the expected molecular weight of the hydrocarbon vapors to be detected. Glass or stainless steel cylinders can be used for lower molecular weight hydrocarbons (C1-10). Commercially available charcoal tubes or cylinders packed with charcoal are suitable for collection of samples expected to contain higher molecular weight hydrocarbon vapors (C6+).