Just found on frontier's site:
Glycerin - Glycerin is a colorless, odorless, viscous, water-soluble liquid with slightly sweet taste. Vegetable glycerin is made from palm, soybean, coconut or corn oils. Glycerin can also be made from animal fat. To avoid it, look for vegetable glycerin on the label. Glycerin is used as a carrier for flavors, a humectant (a substance that promotes retention of moisture) and as an ingredient in baked goods to preserve moisture and prevent staling. It also has uses in cosmetic formulations for smoothing and softening properties.Frontier carries USP-grade Glycerin 99.7% made from palm oil
Says USP grade, don't know why its not on the bottle. I think it would be just fine.