Another study10 investigated the effect of various types of sulfur-cure systems on the mechanical properties of NR and reported similar findings. But, there has been relatively limited data available on the effect of different EV sulfur cure systems on the compression set of NBR. Our particular interest was to determine how changes in the loading of CBS and TMTD accelerators and elemental sulfur at a fixed loading of activators in EV sulfur cure system affected the compression set of NBR filled with carbon black and silica solid fillers. This was important because NBR is used extensively to manufacture O-rings and industrial gaskets for high temperature and corrosive environments.13 NBR is a non-crystallizing rubber unlike NR and must be reinforced with solid fillers such as carbon black and silica to improve its mechanical properties.