Pasteurized egg products can be substituted for shell eggs in eggnog, salad dressing and in bakery items. And a final reminder. Use a meat thermometer to measure the temperature of the dish, or be sure that a cooked base mixture coats a metal spoon. Egg dishes may also be refrigerated for later use, but use within 3-4 days. In 1989, three people were hospitalized in New York after consuming a commercially prepared garlic oil that hadn't been refrigerated.
Oils are thick, and parts of a bottle of infused oil can definitely be oxygen free.
To be safe, commercially prepared infused oils must contain agents such as phosphoric acid or citric acid or some other agent to make the oil too acidic for bacteria to grow. These acidifying ingredients are not available to the home cook. In fact, the Food and Drug Administration requires commercially infused oil products to not only be acidified, but to be processed in a particular way and to carry on the label a message to refrigerate the jar or bottle after opening. Unfortunately, when someone gives you a bottle of homemade infused oil as a present, there is no way to know how it was prepared. You can't tell if an oil is bad by smelling or looking at it.