Cassia oil is an essential oil extracted from the leaves, bark and twigs of the Cinnamomum cassia plant, also known as Chinese cinnamon. It is a yellow or brownish liquid with a warm, spicy and woody aroma. It is commonly used in the food industry as a flavoring agent, particularly in sweet and savory dishes, and in the cosmetic and perfumery industries as a fragrance ingredient. It has been used in traditional medicine to help with digestion and to relieve pain, it's also used as a natural remedy for colds and flu. Cassia oil is considered to be more potent than Ceylon cinnamon oil, so it should be used with caution. It is considered safe for use in food and personal care products when used in appropriate concentrations, but it should be used with caution as high doses may be toxic.