This was in their F & Q section. Are Your Fragrance Oils Skin-safe? Yes, the vast majority are (except for a few from our Value-Line Fragrances), but only when diluted. The Scent Works® fragrance oils are not perfume oils but highly concentrated, manufacturer's-grade products, for professional use only[a], and NOT for direct use on the skin. We recommend an absolute maximum concentration of twenty percent (20%) in any solution"] in accordance with IFRA(5) guidelines. [a] Fragrance oils are combustible or flammable, may contain hazardous substances that present physical and/or health dangers, and require special precautions and spill/leak procedures, with special protective equipment and control measures. Persons and/or organizations unfamiliar with these dangers should refrain from use. You should always test your fragrance oil body compounds (bath gels, creams, lotions, etc.) for skin irritation and general safety. Our Limitations Of Liability provisions apply.