Celery oil is an essential oil extracted from the seeds of the Apium graveolens plant, also known as celery. It is a clear to pale yellow liquid with a strong, spicy and fresh aroma. It is commonly used in the food industry as a flavoring agent, particularly in savory dishes and soups. In traditional medicine, it's used to help with digestion, to relieve pain and to lower blood pressure. It is also used in the cosmetic and perfumery industries as a fragrance ingredient and as a natural remedy for skin problems such as eczema and psoriasis. Due to the presence of phototoxic compounds, it's recommended to avoid sun exposure after applying celery oil to the skin. Celery oil 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.