The products that ZEVA Essential Oils offers are 100% ISO certified essential oils derived from plant sources, and manufactured to contain active phytochemicals from plants without fillers or chemicals. ZEVA only uses oils certified by the Medicinal Oil Association, and we source our plants from quality suppliers throughout the world. However, because of the differences in organic certification from country to country, and even from one state to another in the U.S., it is not possible to acquire raw materials that are all certified organic. We do check our plant supplies for chemical residues in the form of solvents, herbicides, pesticides, and extenders so we can offer products that are as pure as possible, often exceeding the standards for certified organic products.