the US Food & Drug Administration (FDA); a product with a cosmetic use is not (unless information shows that "it is unsafe when consumers use it according to directions on the label, or in the customary or expected way, or if it is not labeled properly".) The US Federal Trade Commission (FTC) regulates any aromatherapy advertising claims. There are no standards for determining the quality of essential oils in the United States; while the term "therapeutic grade" is in use, it does not have a regulatory meaning. Analysis using gas chromatography and mass spectrometry has been used to identify bioactive compounds in essential oils. These techniques are able to measure the levels of components to a few parts per billion. This does not make it possible to determine whether each component is natural or whether a poor oil has been "improved" by the addition of synthetic aromachemicals but the latter is often signalled by the minor impurities present. For example, linalool made in plants will be accompanied by a small amount of hydro-linalool whilst synthetic linalool has traces of dihydro-linalool. Effectiveness There is no good medical evidence that aromatherapy can prevent or cure any disease. However, for cancer patients, aromatherapy tests showed mixed results in lowering anxiety and depression symptoms. In 2015, the Australian Government's Department of Health published the results of a review of alternative therapies that sought to determine if any were suitable for being covered by health insurance; aromatherapy was one of 17 therapies evaluated for which no clear evidence of effectiveness was found. Evidence for the efficacy of aromatherapy in treating medical conditions is poor, with a particular lack of studies employing rigorous methodology. A number of systematic reviews have studied the clinical effectiveness of aromatherapy in respect to pain management in labor, the treatment of post-operative nausea and vomiting, managing challenging behaviors in people suffering from dementia and symptom relief in cancer. However, some studies have come to the conclusion that while it does improve the patient's mood, there is no conclusive evidence on how it works with pain management. Studies have been inconclusive because no straightforward evidence exists. All of these reviews report a lack of evidence on the effectiveness of aromatherapy. Safety concerns Aromatherapy carries a number of risks of adverse effects and with this in consideration, combined with the lack of evidence of its therapeutic benefit, makes the practice of questionable worth.