More on the Controversy of Essential Oils Quality and Safety
Last week, I sent out an E-blast to my interested subscribers on the importance of quality when using essential oils. This is a vital consideration because standardization and regulation is not concise for them; therefore, the consumer must be aware of this to protect their safety.
In the United States, aromatherapy is regulated by how it is intended for use: cosmetic, drug, fragrance, food additive for consumption, or “something else.” Therefore, if a claim is made by any natural substance or an essential oil that makes it appear as a drug, and it hasn’t gone through the FDA approval process for this, the claim is in violation of the drug standards. (This does not imply that the oil itself is unsafe, rather, that the proper protocol for approval was not adhered to.)
Now, before we dig in, it’s important to remember that just because something is regulated, approved, standardized, or widely available doesn’t mean it is inert, especially when misused. This means for the safe use of any substance, natural or synthetic, following the instructions for intended and proper use, not over-dosing, using common sense, and considering the individual’s unique biochemistry and health history are all paramount.
Four Factors of Essential Oil Quality & Safety Misunderstanding
There exists much confusion and contention within different schools of aromatherapy and the public sector on essential oil safety and use. I have to admit; I have been muddled at times by all of this, as some can be quite volatile in their opinions. (Pun intended.) This is due to several reasons:
1. The Complexity Factor
The research is very multifaceted and diffuse on different aspects of essential oils quality. For example, I dare you to skim the following:
- This book, which describes different production techniques, chemistry, and sensory properties of essential oils. There’s also an interesting section on ways to find enantiomers and the importance of plant preparation. (Scroll to the essential oils sections starting on page 57, some pages are not available in this preview)
- This book is on the chemistry and production of essential oils.
Warning- you may need a PhD in chemistry to get through them!
The bottom line is that the extraction and distillation of essential oils is a precise science. The constituents present vary due to factors in growing, harvesting, manufacturing. Production and testing methods need to be considered for quality. (More on this below.)
2. Opinions and Blog Overshadowing of Science (Ode and Plead to My Beloved PubMed!)
There exists so many conflicting opinions touted as facts on the internet that they overshadow our friend of science, PubMed. I’m sure you’ve experienced the same eye-crossing results on Dr. Google when searching for something relating to essential oils. Furthermore, I was a little disappointed in my friendly database for “essential oils quality.” I found some very diverse finds, shown here. Not exactly what I was looking for. (Remember with any blog, including this one, check the references. If there aren’t any, distinguish between an opinion, experience, and a fact.)
3. The “What Does That Say?” Effect
Then, there is the language barrier. How many times have you gotten excited about an article and found out it was in a foreign language? Frustrating, right!!? (Or just put yourself in a geek’s shoes and imagine the frustration.)
This article was so promising, indicating the importance of quality and the differing constituents in standardized oils. I was so excited to find it. Check it out (bold emphasis mine):
Essential oils on the market were analyzed using GC-MS and the main ingredients of each essential oil were quantified. Analysis of the essential oil of Lavandula officinalis (lavender oil) showed that each sample had a different ratio of the contents of main ingredients, such as linalool, linalyl acetate, and camphor. In addition, some commercial lavender oils were analyzed by GC-MS for comparison with the Lavandula flagrans (lavandin oil) and the reference standard. As a result of this analysis, although the components of almost all commercial lavender oils were approximately the same as those of the reference standard, there were a few products that contained more than 0.5% of the amount of camphor in lavandin oil. This suggests that some lavender oil samples are mixed with lavandin oil to lower the price. Commercial essential oils of Melaleuca alternifolia (teatree oil) and Mentha piperita (peppermint oil) were also analyzed by GC-MS. Each of the peppermint oil samples had a different ratio in the content of its main ingredient. With respect to teatree oils, the amount of terpinens in each sample differed. These results led to concern about the efficacy of essential oils. For achieve the expected efficacy of essential oils, correct information on their ingredients should be available and quality control using instrumental analysis should be introduced.
Alas, look at the source: Mori M, Ikeda N, Kato Y, Minamino M, Watabe K.[Quality evaluation of essential oils]. [Article in Japanese]. Yakugaku Zasshi. 2002 Mar;122(3):253-61
Guess, that foreign language classes are in my near future…maybe.
4. The Division Among Our Own Oil Lovers
There is a disturbing schism that exists with “lovers of essential oils” being “haters” of differing companies and differing application methods. Therefore, rather than uniting a profession who loves essential oils and bringing together the research for helping more people, this division confuses the heck out of most of the public! So sad.
I myself have a preference for a particular company because of my own personal results and the consistent reports of my clients. I am also passionate about quality due to the way I use oils. I do stick with what has worked for me and my clients consistently. However, when reporting the information on this blog, I try to keep the facts and put my experience and company suggestions in a separate section and on a different website clearly delineated.
The (Inordinate) Amount of Consideration Within Each of the Factors Involved in Quality and Safety
Let me just dive into some things to consider when looking at the properties, safety, and quality of essential oils so you can see what I mean by inordinate amount of factors:
- Ensuring there is no contamination and synthetic additives.
- Assessing the secondary metabolites present in different species and chemotypes of the same genus of an essential oil. For example, I discussed how different species of frankincense oils can have differing systemic effects, although they can still result in balancing, harmony, and overlap of one another. I also reviewed this with lavender.
- Medication use and interactions with other health issues. This brings the concept of biochemical individuality into the picture.
- Proper use in children and common sense safety for all.
- Consideration of temperature, extraction methods, and quality of raw materials.
- Distillation effecting secondary metabolites of the same oil. A 2012 article in Alternative Medicine stated the following (bold highlighting is me):
Chemical constituents of Boswellia sacra essential oil fractions were dependent on duration and temperature of hydrodistillation. For example, when essential oils collected from 0–2 h (Fraction I), 8–10 h (Fraction II), and 11–12 h (Fraction III) at 78°C were compared, longer distillation produced higher percentages of sesquiterpenes, between alpha-copaene and caryophyllene oxide (Table? 1). All three fractions were primarily composed of monoterpenes (82.77-90.67%), including alpha-thujene, beta-pinene, and myrcene. Among the monoterpenes, alpha-pinene was the major compound present in all essential oil fractions, ranging from 65.49% to 78.45%. As anticipated, the abundance of alpha-pinene decreased with longer and higher temperature distillation due to its highly volatile nature. Compounds such as borneol, dimethyl ether orcinol, allo-aromadendrene, gamma-cadinene, and caryophyllene oxide were only present in Fraction III essential oil…
We found that boswellic acids contents depended on hydrodistillation duration and temperature (Table? 2). Essential oils prepared from longer distillation time and higher distillation temperature contained greater amounts of boswellic acids. For example, boswellic acids contents in Fractions III (19.6%) and IV (30.1%) were higher than those detected in Fraction I (0.9%) or II (0.8%) essential oil.
There was also a 2013 case study in Alternative Medicine which also reported on the distillation technique for boswellic acid in frankincense.
If you want to find some other cool references on how distillation, harvesting, farming, genetics, social forces, and location affect essential oil quality, along with reinforcing the factors above, this is a great article to dive into. It isn’t as scary as the books, I promise!
The Latest Essential Oil Safety Scare
Recently, there was an article from Vanderbuilt Medical Center stating that the Tennessee Poison Center reported a doubling of children and essential oils exposure in recent years. The article did not state an increase in hospitalizations or side effects. Furthermore, I couldn’t find a source for actual numbers. (The full original article can be found here). Therefore, as soon as I read the press release and did my unsuccessful search, I contacted the reporter.
She was very kind to me and said she had been getting a lot of calls on the release due to essential oils’ popularity. She reported that the piece was meant to highlight her conversations with toxicologists on the increasing use of essential oils and exposure to children. The fact is children getting into the oils and swallowing large quantities is bad. However, this was the misuse of essential oils, not a safety issue with the proper dosing. She stated that she never meant for it to be spun and construed that essential oils were unsafe in general.
Unfortunately, this ignited and resurfaced some of the studies that are often quoted regarding the toxicity of essential oils and children. These sources for toxicity where some of the very same ones in which I reviewed and discussed the caveats to here. The sources that are referenced by the poison center also were lacking in some information I was seeking. They do not include the essential oil company, quality of the oil, and some where related to one isolated or synthetic constituent. The parts of an essential oil are not the same as the synergy of the whole essential oil.
This connects to the issue of quality essential oils, because isolation of one component and synthetic fragrances or substances added to an essential oil can be toxic.
It is very important to recognize the limitations and strengths of both standardizations and regulations and to determine the quality of an essential oil for personal use. It is also important to know the facts versus opinions on safety and your preference for essential oil use.
Also, don’t forget to read more about standardizations, regulations, quality control and essential oils here.
Food and Drug Administration. Aromatherapy. FDA Web site: http://www.fda.gov/Cosmetics/ProductsIngredients/Products/ucm127054.htm. Accessed December 28, 2015.
Food and Drug Administration. Fragrances in Cosmetics. FDA Web site: ttp://www.fda.gov/Cosmetics/ProductsIngredients/Ingredients/ucm388821.htm. Accessed December 28, 2015.
Food and Drug Administration. CFR – Code of Federal Regulations Title 21. FDA Web site: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=182.20
Food and Drug Administration. How FDA Evaluates Regulated Products: Drugs. FDA Web site: http://www.fda.gov/AboutFDA/Transparency/Basics/ucm269834.htm
Food and Drug Administration. Pharmaceutical Quality/Manufacturing Standards (CGMP). FDA Web site: http://www.fda.gov/drugs/guidancecomplianceregulatoryinformation/guidances/ucm064971.htm
International Standardization Organization. ISO/TC 54 – Essential oils. ISO Web site: http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_tc_browse.htm?commid=48956..
Association of French Normalization Organization. Standards- All Published Standards. AFNOR Web site: http://www.afnor.org/en/profiles/activity-area/industry/normes/normes/%28limit%29/25/%28page%29/2
Association of French Normalization Organization. ISO 9001 Certification – Quality. AFNOR Web site: http://www.afnor.org/en/certification/smq001#p17578
Association of French Normalization Organization. Normes. AFNOR Web site: http://www.boutique.afnor.org/recherche/resultats/categorie/normes/ics/huiles-essentielles-71.100.60%20?utm_source=portail&utm_medium=referral&utm_campaign=editions.
Smith, T. Tennessee Poison Center at Vanderbilt sees rise in children ingesting essential oils.
Tennessee Poison Center. 05-03-16 What are the commonly used but potentially toxic essential oils? http://www.mc.vanderbilt.edu/root/vumc.php?site=poisoncenter&doc=48694
Kayode RMO, Afolayan AJ. Cytotoxicity and effect of extraction methods on the chemical composition of essential oils of Moringa oleifera seeds. Journal of Zhejiang University Science B. 2015;16(8):680-689. doi:10.1631/jzus.B1400303.
Sawamura M, Son U-S, Choi H-S, et al. Compositional changes in commercial lemon essential oil for aromatherapy. The International Journal of Aromatherapy. 2004; 14:27-36.
Khangholil S, Rezaeinodehi A. Effect of drying temperature on essential oil content and composition of sweet wormwood (Artemisia annua) growing wild in Iran. Pak J Biol Sci. 2008 Mar 15;11(6):934-7.
Oztürk M, Tel G, Duru ME, Harmandar M, Topçu G.The effect of temperature on the essential oil components of Salvia potentillifolia obtained by various methods. Nat Prod Commun. 2009 Jul;4(7):1017-20.
Factors affecting secondary metabolite production in plants: volatile components and essential oils. Flavour Fragr. J. 2008; 23: 213–226
Ni X, Suhail MM, Yang Q, et al. Frankincense essential oil prepared from hydrodistillation of Boswellia sacra gum resins induces human pancreatic cancer cell death in cultures and in a xenograft murine model. BMC Complementary and Alternative Medicine. 2012;12:253. doi:10.1186/1472-6882-12-253.
Fung KM, Suhail MM, McClendon B, Woolley CL, Young DG, Lin HK. Management of basal cell carcinoma of the skin using frankincense (Boswellia sacra) essential oil: A case report. OA Alternative Medicine 2013 Jun 01;1(2):14.