biofuel based on: Suitability as a fuel, based on flash point, energy content, viscosity, combustion products and other factors Cost, based in part on yield, effort required to grow and harvest, and post-harvest processing cost Multipurpose oils also used as biofuel The oils listed immediately below are all (primarily) used for other purposes all but tung oil are edible but have been considered for use as biofuel. Castor oil, lower cost than many candidates. Kinematic viscosity may be an issue. Coconut oil (copra oil), promising for local use in places that produce coconuts. Colza oil, from Brassica rapa, var. oleifera (turnip) is closely related to rapeseed (or canola) oil. It is a major source of biodiesel in Germany. Corn oil, appealing because of the abundance of maize as a crop. Cottonseed oil, the subject of study for cost-effectiveness as a biodiesel feedstock. False flax oil, from Camelina sativa, used in Europe in oil lamps until the 18th century. Hemp oil, relatively low in emissions. Production is problematic in some countries because of its association with marijuana. Mustard oil, shown to be comparable to Canola oil as a biofuel. Palm oil, very popular for biofuel, but the environmental impact from growing large quantities of oil palms has recently called the use of palm oil into question. Peanut oil, used in one of the first demonstrations of the Diesel engine in 1900. Radish oil. Wild radish contains up to 48% oil, making it appealing as a fuel. Rapeseed oil, the most common base oil used in Europe in biodiesel production. Ramtil oil, used for lighting in India. Rice bran oil, appealing because of lower cost than many other vegetable oils. Widely grown in Asia. Safflower oil, explored recently as a biofuel in Montana. Salicornia oil, from the seeds of Salicornia bigelovii, a halophyte (salt-loving plant) native to Mexico. Soybean oil, not economical as a fuel crop, but appealing as a byproduct of soybean crops for other uses. Sunflower oil, suitable as a fuel, but not necessarily cost effective. Tigernut oil has been described by researchers in China as having "great potential as a biodiesel fuel." Tung oil, referenced in several lists of vegetable oils that are suitable for biodiesel. Several factories in China produce biodiesel from tung oil. Inedible oils used only or primarily as biofuel These oils are extracted from plants that are cultivated solely for producing oil-based biofuel. These, plus