Introducing hydrogen into the existing natural gas pipeline network has been proposed as a way of decreasing greenhouse gas (GHG) effects from the combustion of natural gas. However, hydrogen is known to degrade the strength of many alloys through hydrogen embrittlement (HE). Therefore, it is important to carefully define the maximum allowable pressure hydrogen concentration for each alloy to avoid detrimental effects to the material. In this study, hydrogen testing was carried out to evaluate the susceptibility of selected alloys to hydrogen embrittlement via controlled exposure to methane gas blended with different hydrogen concentrations and at different pressures. In addition, a diffusible hydrogen test was carried out to identify the amount of solid solution hydrogen in the samples. The alloys were representative of common regulator materials used in gas pipeline products. Tensile samples with a highly polished surface were tested under five different environments: 1.6 MPa (16 bar) of 10% and 50% hydrogen gas mixture, and 10 MPa (100 bar) of 10%, 30%, and 50% hydrogen gas mixture after soaking between 2 days and 5 weeks. Tests on control samples were performed in ambient environment. The results from this study provide insight into the effects of hydrogen on various alloys under five different environments and indicate which alloys performed best under a given environment.