The ABC-AHP-NCNPR Botanical Adulterants Prevention Program (BAPP) has released a new Laboratory Guidance Document (LGD) on English lavender essential oil.
 
Essential oil of the English lavender plant (Lavandula angustifolia) is made through steam distillation of the flowering tops of the plant. The oil is widely used orally, or via inhalation to promote restful sleep and relaxation. It’s also a popular ingredient in massage oils, personal care, home care, and cosmetic products.
 
The wholesale price of bulk essential oil ragnes from $75-$100 per liter. Due to this high price, undisclosed substitution with essential oils from other lower-cost species of Lavandula appears common. One of the reported adulterants is essential oil from lavandin, which some authorities consider an acceptable substitute.
 
Other types of adulteration include undeclared addition of other kinds of essential oils, or oil fractions that are rich in linalool, a natural compound. Mixtures of undisclosed purified or synthetic chemicals like linalool or linalyl acetate, or non-volatile fatty oils like sunflower oil added as a diluent, have also been reported.
 
“English lavender is a name often misused by laymen due to its morphological and chemical similarities with other species of Lavandula and its commercial hybrid lavandin,” said essential oil expert Kemal Hüsnü Can Başer, PhD, a professor in the Pharmacognosy Department of the Faculty of Pharmacy at Near East University in Nicosia (Lefkoşa, Northern Cyprus).
 
Başer is the co-editor of Essential Oils: Science, Technology, and Applications, 2nd edition (CRC Press, 2015), which received the ABC James A. Duke Excellence in Botanical Literature Award in 2017. 
 
Başer noted that there are standards for lavender and lavandin oils established by ISO, and the European Pharmacopoeia contains monographs of lavender and spike lavender oils. “These standards can help authenticate the essential oils.”
 
“Some of the methods of lavender oil adulteration are easy to detect,” said Stefan Gafner, PhD, chief science officer for the American Botanical Council and the director of BAPP. “For example, vegetable oils or compounds known as glycols leave a liquid residue when a drop of oil is placed on filter paper, while essential oils evaporate. On the other hand, some types of adulteration are difficult to determine because fraudsters have found ways to produce materials that resemble English lavender oil very closely. The new BAPP LGD provides an overview of the available laboratory analytical methods and their strengths and limitations, so quality control personnel in various industries can readily find the right approach for their needs.”
 
The new laboratory guidance document (LGD) was written by Oleksandr Shulha, PhD, an expert in natural products chemistry and analysis based in Cherkasy, Ukraine. It provides an evaluation of the macroscopic and microscopic features for English lavender flowers, and 48 other analytical methods, including 17 gas chromatography and seven infrared spectroscopy methods, with respect to their suitability to properly determine the identity of lavender essential oil. The LGD was peer reviewed by 16 quality control experts from academia and the herb industry in the U.S. and other countries.