This is what I found on Google Kate:
Q: Olive oil comes from olives, peanut oil from peanuts, sunflower oil from sunflowers, but where does canola oil come from--is canola oil rapeseed oil?
A: No. Canola oil comes from canola seed. Canola is the name given to a very healthy oil that was developed from rapeseed. But it is not rapeseed oil and has vastly different fatty acid and other properties than rapeseed oil. Canola was developed using traditional plant breeding methods to remove undesirable qualities in rapeseed. In terms of their properties, canola oil is as different from rapeseed oil as olive oil is as different from corn oil.
Q: Are canola oil and rapeseed oil poisonous to living things?
A: No. However, since rapeseed oil has high levels of erucic acid, canola oil is healthier for you. Rapeseed oil is not used in our food supply except in minute amounts as an emulsifier in a few processed foods. For example, some brands of peanut butter contain minute amounts of rapeseed oil to prevent the peanut oil separating from the peanut butter. This use is approved by Canadian and U.S. food regulatory agencies backed by research showing this use is absolutely safe. The rapeseed oil used in these few processed foods is fully hydrogenated and, therefore, no longer rapeseed oil. Full hydrogenation of rapeseed oil results in the total saturation of erucic acid. When erucic acid is fully hydrogenated, it forms a common saturated fatty acid called behenic acid. Behenic acid is naturally present in peanuts, peanut oil and peanut butter. A few processed food labels may say the products contain rapeseed oil (as an emulsifier) but since the rapeseed oil has been fully hydrogenated, it is not rapeseed oil. Rapeseed is grown on very limited acreages under contract between the grower and the buyer (it doesn't get into the regular grain handling system). Liquid high erucic acid rapeseed oil is used for industrial purposes and cannot be purchased in food stores. Canola oil has been thoroughly tested and is guaranteed safe for humans. Plus it can lower blood cholesterol and has other health benefits.