OPC stands for organic photoconductor. The term "organic" indicates that the photoreceptor's coating was manufactured from carbon-based chemical compounds -- specifically, photoconductive polymers synthesized from raw materials, that are obtained by refining fossil fuels such as petroleum. OPC drums are generally considered the most "environmentally friendly" photoreceptors available today -- primarily because their designers and manufacturers consciously utilize nonhazardous raw materials. In fact, all materials must pass strict material safety tests before they can be used in OPC manufacturing. This ensures that OPC drums are, in fact, environmentally friendly alternatives to more hazardous photoreceptors such as arsenic triselenide (As2Se3) and selenium tellurium (SeTe) drums. 123 Refills inspects, remanufactures, recoats or replaces OPC drums in the toner cartridges that it remanufactures to guarantee optimal performance in terms of quality and page yield.