Citronella oil is commonly used as an air freshener or as an insect repellent. Known for its antiseptic, bactericidal, deodorant and toning properties, this lemon-scented oil is uplifting and cleansing. It is commonly used as an air freshener or as an insect repellent. Its antimicrobial properties suggest that it is a useful oil for inhalations to protect against colds and flu. Safety information; May cause contact dermatitis in some individuals.