The second edition of this book is practically a new book. It is the only comprehensive text on the safety of essential oils and the first overview of interactions between essential oils and medications, providing detailed data on the components of essential oils that cannot be found in any other text. A large portion of the existing text has been rewritten, and 80% of the text is completely new. There are 400 comprehensive profiles of essential oils and nearly 4,000 references. New chapters cover the respiratory system, cardiovascular system, urinary system, digestive system, and nervous system. For each essential oil, there is a complete breakdown of the components as well as a clear categorization of hazards and risks, including recommended maximum doses and concentrations. There are also 206 profiles of components. The book discusses carcinogens in detail, the human relevance of some animal data, and the validity of treatments.