Concerns about U.S. reliance on imported petroleum and fluctuating fuel prices have led to growing interest in using biodiesel, an alternative fuel made from vegetable oils. However, there is also interest in the direct use of vegetable oils as straight or raw vegetable oil (SVO or RVO), or of waste oils from cooking and other processes. These options are appealing because SVO and RVO can be obtained from U.S. agricultural or industrial sources without intermediate processing. However, SVO is not the same as biodiesel, and is generally not considered to be an acceptable vehicle fuel for large-scale or long-term use.