"Chemistry is one of those areas that students and practitioners often find rather daunting and more than a little incomprehensible, Sue Clarke’s book Essential Chemistry for safe Aromatherapy attempts to redress this and presents the basics of chemistry in the context of aromatherapy practice in a clear and straightforward manner. The text begins with an overview of fundamental chemical concepts (eg chemical bonding, molecules) and then progresses to look at organic chemistry in more depth and the chemistry of compounds found in essential oils in particular. The text also includes chapters on the processing and extraction of essential oils and the analytical techniques used to determine essential oil composition and purity such as gas chromatography mass spectrometry and infrared spectroscopy. These chapters will be useful to anyone who needs to understand how essential oils are analyzed and what the ‘squiggly lines’ on GC-MS and other traces mean. The last section of the book deals specifically with essential oils. Chapter 6 covers essential oils composition from a general perspective and then looks at 12 common essential oils used in aromatherapy (eg lemongrass, lavender and ylang ylang) and also carrier oils, such as jojoba oil, that may be used with essential oils. The last chapter covers issues of safety and handling, for example the reasons for storage of essential oils in dark glass bottle away from heat sources, as well as routes of administration of essential oils. The glossary at the end of the text will also be useful resource for those working in the area particularly for those just be looking for a reminder or clarification of a particular area or term in chemistry. Overall the text is a highly readable introductory discussion of organic chemistry and the impact of an understanding of that chemistry on essential oils and their use in aromatherapy. While this text will not replace a standard chemistry text it will serve as a very useful addition to aromatherapists’ professional libraries. The text would also be a good introduction to chemistry for those who have perhaps had a poor experience with chemistry in the past or who are new to the area. The text contains a large number of diagrams and pictures that serve to illustrate the text and greatly enhance the written text. I particularly liked the Aromafacts scattered throughout the text. These short (generally 1-3 sentences) descriptions serve to link the pure chemistry with aromatherapy and are an excellent way to demonstrate the relevance of the chemistry. For example on the very first page of the main text the Aromafact explains that chemicals are not ‘bad’ things, that all substances are made of chemicals and that chemistry helps us to understand how these chemicals are important to the biological actions of essential oils. This Aromafact sets the tone and style for the rest of the text and is built upon by the other Aromafacts in the text. Does the text provide sufficient chemistry for safe aromatherapy? Probably, although the discussion of essential safety for both client and practitioner is perhaps not a strong as I would have expected given the title of the book. However it is perhaps a little unfair to expect a relatively slim volume to cover all aspects of this area and the author makes no claims that this is the definitive volume of essential oil safety. The strength of this text lies in the way in which chemistry and chemical concepts are presented in a context relevant to aromatherapists. Readers who have interests in the more physiological aspects of essential oil chemistry and safety can use the bibliography and additional resources section which contains a details of web sites, books and journals in the area. Would I recommend this text to others? Yes – this is one of the clearest and most well written texts on chemistry I have seen. All complementary practitioners who use essential oils would find this a valuable resource for understanding the chemistry behind the action of these products and how to use essential oils safely. This book should certainly take the 'fear-fact' out of understanding essential oil chemistry. "