An onboard refueling vapor recovery system (ORVR) is a vehicle fuel vapor emission control system that captures volatile organic compounds (VOC, potentially harmful vapors) during refueling. There are two types of vehicle fuel vapor emission control systems: the ORVR, and the Stage II vapor recovery system.
A system designed to capture harmful fumes released during refueling is installed on vehicles, known as an onboard refueling vapor collection system (ORCS). This system falls into one of two categories: the ORCS or the Stage II vapor recovery system.