"Partially Hydrogenated Vegetable Oil" means it is still somewhat unsaturated (contains double bonds in the carbon chain); it is the fully hydrogenated oil (done to make it more like fat or lard, which companies early thought people knew and were used to) that may have some adverse health effects. A small amount used to improve pourability should not be of concern. Of course, what is you eat is your personal choice. The healthiest would be to eat the salad without dressing.