There are quite a few EOs that are safe for lip balms: Sweet Orange, Cinnamon, Spearmint/Peppermint, Ginger, Grapefruit, Geranium, Anise, Lavender, Lemongrass...just to name a few. If its used in food, it is usually safe for lip balm. The trick is in the percentage used - 0.5% to 1% of your base is usually fine. I have used all of the above with no issues. Some people are just more sensitive to EOs like the mints or Cinnamon, and some of the Citrus oils can cause photosensitivity so keep that in mind when figuring your proportions.