Bulletins on Adulteration of Tea Tree Oil and Rhodiola rosea Published by the Program

Recent reports have provided evidence for rather widespread economically-motivated adulteration of tea tree oil, the essential oil obtained by steam distillation of the leaves and terminal branchlets of Melaleuca alternifolia (Myrtaceae) and M. linariifolia. Adulterants include synthetic terpinen-4-ol, or industrial by-products from ‘normalizing’ eucalyptus, and other essential oils such as pine and white camphor. The Botanical Adulterants Bulletin on tea tree oil, authored by Ezra Bejar, PhD, provides a summary of the available information on the issue with details on the tea tree oil market, known adulterants, adulteration frequency, and analytical methods to detect admixture of, or substitution with, lower-cost materials. Released on August 24, 2017, the bulletin has been peer-reviewed by 18 experts in the fields of the tea tree oil trade or quality control of botanical ingredients.

Published on October 16, 2017, the Botanical Adulterants Bulletin on Rhodiola rosea substitution and adulteration summarizes issues with the identity of materials labeled to contain Rhodiola rosea (syn. Sedum rosea, Crassulaceae). While scientific research initiated in Russia and continued by researchers from Western countries has established Rhodiola rosea as the main source for dietary supplements and phytomedicines in Western countries, traders in China, the main supplier of rhodiola, do not consider R. rosea as the primary or authentic species. Other species such as R. crenulata, which are more abundant, are not considered to be a substitute or an adulterant for R. rosea, and are sold under the common name of hong jing tian. As such, the Chinese name hong jing tian generally refers to multiple rhodiola species, which are all considered acceptable materials in the Chinese trade. In addition to explaining the trade differences, the rhodiola bulletin, co-authored by Ezra Bejar, PhD, John Cardellina, PhD, and Roy Upton, provides a summary on investigations into the identity of commercial materials, nomenclature issues, and testing methods to distinguish among the Rhodiola species. It has been peer-reviewed by 19 experts from academia, contract testing laboratories, and the botanical dietary supplements industry.