Keeping Your Lavender Fresh and Safe
A couple of recent journal-published studies have made a strong case for keeping your Lavender essential oil fresh. Apparently the linalool (a natural constituent of the oil, which actually provides its calming sweetness) can oxidize relatively rapidly. This is not likely to be easily detected by the nose, but has been discovered in the lab. The only concern revealed thus far is application of Lavender oil to the skin once a significant portion of the oxidized linalool is present -- some folks can have an allergic reaction to it. This may not affect the aromatic soothing effect of the essential oil at all.
In any case, it would be best to keep your stock of Lavender in the refrigerator (this nearly halts oxidation), in the smallest bottle possible, allowing for the least amount of air space. Decant the amount of oil you'll use throughout the next month in a dropper bottle in your living space, first aid kit, etc. This does not imply one should stop using Lavender essential oil, as it is one of aromatherapy's most oils! Just be conscientious of its storage.
Here are the studies:
Lavender oil lacks natural protection against autoxidation, forming strong contact allergens on air exposure.
Hagvall L, Sköld M, Bråred-Christensson J, Börje A, Karlberg AT.
Department of Chemistry, Dermatochemistry and Skin Allergy, Göteborg University, Gothenburg, Sweden.
BACKGROUND: Lavender oil is an essential oil frequently used as a fragrance ingredient and in traditional herbal medicine. We have previously studied the effect of air oxidation on the skin sensitizing potency of the monoterpenes linalyl acetate, linalool and beta-caryophyllene, the main constituents of lavender oil. OBJECTIVE: The aim of this study was to investigate if the autoxidation observed for the single synthetic terpenes, resulting in strong contact allergens, will take place also in lavender oil. METHODS: Lavender oil was exposed to air and the autoxidation was followed by chemical analysis. The sensitizing potency before and after air exposure was investigated in mice using the local lymph node assay. Patients with patch test reactions to oxidized linalool were tested to investigate if air-exposed lavender oil could elicit dermatitis in these individuals. RESULTS: The terpenes oxidized in air-exposed lavender oil at the same rates as the pure compounds exposed to air, and the same oxidation products were identified. The sensitizing potency of lavender oil increased accordingly on air exposure. Patch testing showed positive reactions to air-exposed lavender oil and also to oxidized linalyl acetate in patients with contact allergy to oxidized linalool. CONCLUSION: This study shows that lavender oil lacks natural protection against autoxidation, and that air-exposed lavender oil can be an important source of exposure to allergenic hydroperoxides.
Results of patch testing with lavender oil in Japan.
Sugiura M, Hayakawa R, Kato Y, Sugiura K, Hashimoto R.Department of Environmental Dermatology, Nagoya University School of Medicine, Japan.
We report the annual results of patch testing with lavender oil for a 9-year period from 1990 to 1998 in Japan. Using Finn Chambers and Scanpor tape, we performed 2-day closed patch testing with lavender oil 20% pet. on the upper back of each patient suspected of having cosmetic contact dermatitis. We compared the frequency of positive patch tests to lavender oil each year with those to other fragrances. We diagnosed contact allergy when patch test reactions were + or <+ at 1 day after removal. The positivity rate of lavender oil was 3.7% (0-13.9%) during the 9-year period from 1990 to 1998. The positivity rate of lavender oil increased suddenly in 1997. Recently, in Japan, there has been a trend for aromatherapy using lavender oil. With this trend, placing dried lavender flowers in pillows, drawers, cabinets, or rooms has become a new fashion. We asked patients who showed a positive reaction to lavender oil about their use of dried lavender flowers. We confirmed the use of dried lavender flowers in 5 cases out of 11 positive cases in 1997 and 8 out of 15 positive cases in 1998. We concluded that the increase in patch test positivity rates to lavender oil in 1997 and 1998 was due to the above fashion, rather than due to fragrances in cosmetic products.
*The FDA has not evaluated the statements on this website. The information presented here is for educational purposes of traditional uses and is not intended to diagnose, treat, cure, or prevent any diseases.