ANSWER: There are a wide variety of essential oils marketed to consumers every year, and not all of them are 100% ISO certified aromatic oils. Occasionally companies will add fillers, compounds, and other chemicals to their oils, and since there are no regulatory standards for terms like “therapeutic grade” oils, companies can often misrepresent their product. ZEVA Essential Oils contain only 100% ISO certified essential oils with all the active phytochemicals drawn from plants, and we never use fillers, compounds, or chemical additives. It’s our guarantee that we only use the highest quality essential oil extracts that meet our standards for purity.