We don't have a policy per se, but I think you're referring to trans fats, and oils in their liquid form don't contain trans; it's the process of hydrogenation that creates the trans. I think there's still some debate within science as to the relationship between trans and saturates and which are worse, but I think trans may be losing the argument.
Fats are made up of fatty acids, and the fatty acid composition is what basically determines what they're best used for. Something such as canola, which is low in saturates, is a natural liquid oil. Soybean oil has about twice the level of saturated fat. It needs less hydrogenation than a canola would.