Vegetable Oils/Fats are the most heat-sensitive so you could keep them in the fridge for prolonged shelf life. Never keep fragile vegetable oils and essential oils in the fridge door as it will be shaken often and therefore oxidised and the free radical destruction process will start again and again. If a product has no fats or oils in them, then it is easier to extend their shelf life, for example, tinctures and herbs.
Let us say you have 2 months left on the shelf life of a vegetable oil and you want to use it in a cream or lotion. My experience has taught me that by using it in the heating process to make a cream recipe, you extend the shelf life to at least 1.5 years. I wouldn’t consider an extended shelf life if you just blended it in a massage oil blend or with Vitamin E Oil. Otherwise, the rule is that the higher part of Omega 3/or GLA Oils you have in the oil, the more fragile the oil will be. Never buy Raspberry Oil, Kiwi Seed, Rosehip, Hemp Seed, Evening Primrose or Borage Oils without them having an added antioxidant to them. An antioxidant like Vitamin E Oil or Rosemary CO2Extract has to be added when produced or the oil must be capped and the bottle flushed with nitrogen gas when produced. The difference can be a shelf life of 1.5 – 2 years instead of 6 months.