Lee Tea is an investigative journalist with a focus on essential oil consumer advocacy.
BEFORE WE BEGIN -
A small but consistent portion of my audience reaches these articles seeking help during crisis and essential oil emergency situations.
Please forgive this short forward to help those in need. Thank you kindly.
If you are CURRENTLY EXPERIENCING an ADVERSE REACTION
to essential oil use, it is advised you seek medical attention immediately:
- Call 911
- Poison Control at 1-800-222-1222
- or your doctor.
and HAVE THE BOTTLE and LABEL from the essential oil with you!
as the label may help inform emergency and medical personnel so they can determine the best course of treatment.
Remember you can contact Poison Control whether or not your situation is an emergency, as they also offer general information and preventative instruction. Take advantage!
and Uses of Essential Oils
Essential oils are the potent, concentrated aromatic oils that can be extracted from some plants, commonly herbs and spices.
These plant oils are used for their fragrance, flavor, health, and cleaning properties, typically in prepared products such as cosmetics, perfumes, baked goods, supplements, and cleaning products.
When properly prepared, essential oil products offer a natural and often effective substitution to synthetically produced petrochemical products. Using the potent, pure essential oils unprepared and undiluted however naturally increases the number of potential side effects associated with their use.
In particular, this paper will examine the risks associated with the ingestion of pure, undiluted lemon essential oil.
Sources and Uses of Lemon Essential Oils
Lemon essential oil (Citrus limon, Citrus medica limonum) is usually obtained from the lemon peel by method of cold pressed extraction. Calculations from information obtained here suggest it takes about 80 to 100 lemons to produce 1 oz of lemon essential oil.
"The use of essential oils can be safe provided that the percentage use, product application, target consumer and all of the toxicology data have been carefully evaluated and considered. It is never wise to use an essential oil without first diluting it in a carrier oil." - Dweck, "Toxicology of Essential Oils Reviewed"
A cold expression of peel yields approximately 4% extract based on the weight of the fruit. Lower quality essential oil is produced through steam distillation and is not noted to be phototoxic like its cold pressed counterpart. (http://toxnet.nlm.nih.gov...)
In its pure form, lemon essential oil has a clean, sweeter scent with a dynamic hint of sour and is used in aromatherapy and as a top note in perfumery. Lemon essential oil is also used to flavor foods, pastries, medicaments, liqueurs and beverages. Because of its solvent abilities, lemon essential oil can be found as an ingredient in wood cleaners and paint strippers where it is used in place of turpentine. Lemon essential oil is also sometimes used as a natural insecticide.
Composition of Lemon Essential Oil
In addition to the popular use of lemon essential oil for its scent, flavor, and solvency, the individual constituents that make up lemon essential oil are themselves popular and frequently used for these reasons.
A 1991 article in the Journal of Agricultural and Food Chemistry reports lemon essential oil produced from both Sicilian and California lemons contains at least 51 individual constituents as quantified in a single gas chromatography analysis. A review of the GC analyses of over 40 different lemon essential oil samples from a variety of countries published by EssentialOil.university typically displays 20 to 59 constituents.
Different Extraction Methods Yield Different Oils
Citrus essential oils like lemon harvested by steam distillation contain only volatile compounds. Essential oils extracted through cold-pressing the peels contain both volatile (85 - 99%) and nonvolatile (1 - 15%) compounds. (http://chromsci.oxfordjournals.org/content/42/8/410.full.pdf, Jan 2015)
Methods of analyzing essential oils differ and, as a result, so do the results they produce. However, generally speaking, the three major components of lemon essential oil can consistently be expected to be limonene, beta-pinene (b-pinene) and gamma-terpinene (y-terpinene) as identified by Chamblee et. al. (1991) and verified by GC analyses reviews at EssentialOil.University.
The main component of lemon essential oil consistently appears to be the terpene limonene, generally found in concentrations of around 65 - 80%. (http://toxnet.nlm.nih.gov... under "general manufacturing information" and verified by GCs analyses reviews at essentialoil.uni)
Examination of the Main Constituents
Limonene (d-Limonene): generally present in concentrations of 65 to 80%
Lemon essential oil's main constituent limonene is a colorless to pale-yellow liquid with a lemon-like odor. It is the predominant monoterpene in citrus oils and is used for its fragrance, flavor, and solvent abilities. (http://toxnet.nlm.nih.gov...)
Variations of Limonene
Limonene is a monoterpene and has two isomeric configurations, d and l (and a combination of the two known as "dl"). d-limonene is a by-product of citrus while l-limonene is derived from pines, and dl-limonene is a component of turpentine. (source: https://www.britannica.com/science/limonene)
Limonene is also sold as a dietary supplement marketed to treat cancer, prevent cancer, and promote digestive health. The amount recommended by physicians to achieve these benefits can be up to 40 times the amount found in a daily serving of fruit, so a dietary supplement has been developed to reach these levels.
Because limonene itself is a solvent, ingesting a tincture or essential oil containing it can irritate the digestive tract. So the d-limonene dietary supplement is usually produced from orange peel oil (which is typically comprised of 90% or more limonene), added to an emulsifying agent (like glycerin), and contained in a capsule to help prevent this irritation.
Limonene is completely absorbed via oral administration, distributed throughout the body's fat and tissue, is metabolized, and is cleared as waste product by the kidneys. (http://toxnet.nlm.nih.gov...)
Side Effects of Limonene Ingestion
When prepared and taken as a dietary supplement, general side effects may include:
- loose stools
When ingested undiluted, the number of potential side effects and their severity increase due to the solvency of limonene:
- burning pain in the throat
- abdominal pain
When encapsulated like in a dietary supplement and taken as instructed, typical side effects may include tiredness, loose stools, and nausea.
When not prepared as a supplement, the number of potential risks associated with digestive tract irritation increases due to the solvent nature of limonene. In addition to the list of associated side effects of the d-limonene supplement, ingestion of limonene may produce burning pain in the throat, abdominal pain, nausea, vomiting, and diarrhea. One study showed that oral administration of d-limonene to 32 patients with tumors produced nausea, vomiting, and diarrhea, with no observable effect on the patients' preexisting tumors.
Large ingestions of preparations containing limonene may produce hematuria (blood in urine), albuminuria (high levels of protein in urine, possibly a result of kidney disease), fever, dyspnea (shortness of breath), tachycardia (rapid heartbeat), and central nervous system effects including excitement, delirium, ataxia, and stupor, though it is unclear whether these particular side effects are a result of the larger amount of limonene ingested or from other ingredients in the prepared product. (http://toxnet.nlm.nih.gov...)
Maximum tolerated doses of limonene are reported from studies to be 8 g/m2 per day where nausea, vomiting and diarrhea were dose limiting. A minimum lethal dose has not been established for limonene, though it has been reported and suggested that a probable oral lethal dose could fall anywhere in the range of 1 ounce to 1 pint for a 150 pound human.
Limonene has the ability to interfere with medication that is processed by the liver and is not recommended for pregnant or nursing women. Potential interactions like these are why it is a good idea to speak with your doctor before beginning any new health regimen.
beta-Pinene (b-Pinene): generally present in concentrations of 4 to 11%
Pure beta-Pinene is isolated from American turpentine, by conversion from alpha-Pinene, and from sulfate wood turpentine. It is used for its flavor and is an approved food additive when used in the least amount necessary to achieve its purpose (http://pubchem.ncbi.nlm.nih.gov...)
Potential Drug Interactions for Limonene
Limonene, the main constituent in lemon essential oil, has the ability to interact with medication that is affected by the liver. Some medications that may affect or be affected by limonene include:
- amiodarone (Cordarone)
- amitriptyline (Elavil)
- carbamazepine (Tegretol)
- cimetidine (Tagamet)
- diclofenac(Cataflam, Voltaren)
- fluconazole (Diflucan)
- fluvoxamine (Luvox)
- glipizide (Glucotrol)
- ibuprofen (Motrin),
- meloxicam (Mobic)
- warfarin (Coumadin)
- losartan (Cozaar)
- paroxetine (Paxil)
- prednisone (Deltasone)
- rifampin (Rifadin, Rimactane)
- secobarbital (Seconal)
- ticlopidine (Ticlid)
- topiramate (Topamax)
- zafirlukast (Accolate)
(Information obtained here by way of Natural Medicines Comprehensive Data Base Consumer Version, Jan 2015)
This list may not be all inclusive. Talk with your doctor before beginning any new health regimen, especially if you are pregnant, nursing, or taking prescription medication.
Pinene is easily absorbed through the pulmonary system, the skin, and the intestine. beta-Pinene is noted to be moderately toxic and irritating to the eyes, respiratory system, skin, and mucous membranes. (http://pubchem.ncbi.nlm.nih.gov...).
Pure pinene is harmful if ingested, inhaled, or in contact with skin. Emergency procedures for the ingestion of beta-Pinene are followed in accordance with the response procedures for turpentine oil. Large absorption and large ingestion of pinene can produce signs of kidney disease/failure, excitement, delirium, loss of muscle control, vertigo, stupor, seizures, and coma. Death is usually the result of respiratory failure.
Probable oral lethal dose of pinene for humans are calculated to likely be between .5 and 5 g/kg, or between 1 oz and 1 pint for a 150 lb. (70kg) person. 150 mL may constitute a human oral fatal dose.
(source: http://toxnet.nlm.nih.gov..., Jan 2015)
gamma-Terpinene (y-Terpinene): generally present in concentrations of 3 to 12%
gamma-Terpinene is an oily, colorless liquid used in the flavor and fragrance industries. It is commonly harvested from tea tree oil (Melaleuca alternifolia) where it is found in concentrations of 10 - 28%. gamma-Terpinene exhibits antimicrobial properties and is widely used as a fungicide for crops, qualifying as a suitable ingredient in organic gardening.
In its pure form gamma-Terpinene is flammable and noted to be a potential eye, skin, respiratory and digestive tract irritant.
Extreme caution is used in handling the pure form of any of these constituents, as evident by review of OSHA mandated Safety Data Sheets. Similar precautions should be considered when handling the lemon essential oil itself, which, although in dilution, contains them all.
Considerations for Some Minor Constituents
Minor constituents have lower concentrations within an essential oil, though concentration amounts can and most likely will differ from differently sourced samples of the same essential oil. These are just a few notable ones commonly found in lemon essential oil. Each has its own set of side effects that should be considered and cumulatively accounted for when blending preparations:
alpha-Pinene: generally present in concentrations of about 2%
alpha-Pinene is an oily and colorless flammable liquid with a turpentine scent used in insecticides, perfumes, plasticizers and solvents. We each consume about 0.02 mg/kg/day from food, and alpha-Pinene is emitted by a variety of plants.
alpha-Pinene is found in turpentine oil in concentrations of 58 - 65% and is on the "Right to Know Hazardous Substances" list in the state of New Jersey as a noted eye, mucous membrane, and "severe" human skin irritant.
Exposure to alpha-Pinene can cause headaches, nausea, and vomiting. Very high exposures of pure alpha-Pinene may affect the central nervous system resulting in loss of coordination, dizziness, seizures, confusion, and coma. (http://nj.gov/health...)
alpha-Pinene is noted in peer reviewed journals to have the same toxicity as turpentine. Child fatality from alpha-Pinene has occurred at 15 mL (1/2 oz). Mean lethal dose in adults is reported to likely range between 4 and 6 oz. Oral exposure treatment protocols for ingestion of alpha-Pinene are explained for seizures and instruct to protect the patient's airway. (http://toxnet.nlm.nih.gov...)
Geraniol and citronellol, generally found in concentrations < 1%
An article on the toxicology of essential oils notes constituents like geraniol, citronellol, and limonene are potential allergens that must be cumulatively accounted for when blending preparations.
More Details on Taking Action for a Reaction
As the information at the beginning of this report advises, if you are currently experiencing an adverse reaction to essential oil use, it is advised to seek medical attention immediately.
Call 911, Poison Control at 1-800-222-1222, or your doctor.
Have the bottle of essential oil available, as the label may help inform emergency and medical personnel so they can determine the best course of treatment.
Safe Use Criteria
Essential oils like lemon are used by the cosmetic, fragrance, cleaning, and flavoring industries and, as such, responsible use of it is addressed by safety organizations that provide information specifically for these industries. Further research on the safe and responsible use of essential oils IS available - seek it out!
"The International Fragrance Association (IFRA) has introduced the Quantitative Risk Assessment (QRA) approach for fragrance ingredients. It is highly recommended that readers acquaint themselves with its website (www.ifraorg.org)."
- Toxicology of Essential Oils Reviewed, accessed Jan 2015
Remember you can contact Poison Control whether or not your situation is an emergency, as they also offer general information and preventative instruction. Essential oils are a category in the American Association of Poison Control Center's Annual Report, they document thousands of essential oil related incidences every year, and the number and severity of incidences has risen every year since at least 2010.
OSHA mandated Safety Data Sheets for businesses which handle lemon essential oil are required by law to note the following:
- ingestion in large doses of lemon essential oil may cause human death
- administer milk or water to dilute if ingestion occurs
- if ingestion occurs, seek medical attention immediately or call a poison control center
Patients with more than minimal symptoms from oral exposure of lemon essential oil or limonene should be observed in a healthcare facility, as mild symptoms can progress into respiratory failure. (http://toxnet.nlm.nih.gov...)
This paper examines the potential side effects of ingesting lemon essential oil by defining the substance in terms of its primary constituents and then examining the oil's major components.
Lemon essential oil and its constituents including limonene, beta-Pinene, and gamma-Terpinene are commonly used in major industries worldwide and so information on their safe use has been scientifically studied and is available. This paper collects information on the potential side effects, interactions, and warnings associated with the constituents most relevant to this essential oil's ingestion and presents it here for your review and consideration.
For More Information on the Safe Use of Essential Oils
For safe and acceptable uses, essential oils require proper preparation in diluted levels that have been established by industry organizations for the safe use of such a powerful concentrated substance. One report notes that the highest levels of lemon peel oil found in commercially available products are in concentrations of .5%, one-half percent or less. For more about the safe and proper use of essential oils for your own preparations, please refer to the guidelines established within the industry most suitable for your needs.
Here are some examples of established organizations dedicated to the study of substances, including essential oils, used within their industries to establish acceptable preparation and use guidelines in the interest of consumer safety:
'A nonprofit corporation established in 1966 to gather and analyze scientific data, engage in testing and evaluation, distribute information, cooperate with official agencies and to encourage uniform safety standards related to the use of flavor and fragrance ingredients. The RIFM Database is the most comprehensive, worldwide source of toxicology data, literature and general information on fragrance and flavor raw materials, classifying more than 5100 materials. The RIFM aims be the International Scientific Authority for the Safe Use of Fragrance Materials.'
Headquartered in Hackensack, NJ, USA with an office in London, England.
'The fragrance industry takes its regulation seriously. All of its ingredients and compounds are rigorously assessed for toxicity and allergens. IFRA members account for 90% of the global production volume of fragrance compounds and the IFRA Code of Conduct prescribes the behaviour that is expected of them.'
"The IFRA Standards form the basis for the globally accepted and recognized risk management system for the safe use of fragrance ingredients and are part of the IFRA Code of Practice.
This is the self-regulating system of the industry, based on risk assessments carried out by an independent Expert Panel."
IOFI invests in sound science to support flavor ingredients safety.
"Research studies in people to prove that a dietary supplement is safe are not required before the supplement is marketed, unlike for drugs. It is the responsibility of dietary supplement manufacturers/distributors to ensure that their products are safe and that their label claims are accurate and truthful. If the FDA finds a supplement to be unsafe once it is on the market, only then can it take action against the manufacturer and/or distributor, such as by issuing a warning or requiring the product to be removed from the marketplace."
"In addition to talking with your health care provider about dietary supplements, you can search on-line for information about a particular dietary supplement. It is important to ensure that you obtain information from reliable sources such as:
- Fact sheets on dietary supplements from the National Institutes of Health
- Nutrient Recommendations: Dietary Reference Intakes (DRI) and Recommended Dietary Allowances (RDA)
- PubMed Dietary Supplement Subset
- Dietary supplement warnings and safety information from the U.S. Food and Drug Administration
- Consumer information from the Federal Trade Commission
For tips on evaluating sources of healthcare information on the Internet, please see the following document: How to Evaluate Health Information on the Internet: Questions and Answers."
Bio-Pesticides Database "Gamma-Terpinene". University of Hertfordshire, Hatfield, Herts., AL10 9AB, UK. Available http://sitem.herts.ac.uk/aeru/bpdb/Reports/2013.htm, accessed Feb 2015
Chamblee, Theresa S and Clark, Brewster, Radford and Iacobucci. Quantitative analysis of the volatile constituents of lemon peel oil. Effects of silica gel chromatography on the composition of its hydrocarbon and oxygenated fractions. Journal of Agricultural and Food Chemistry, 1991, 39 (1), pp 162–169. Available: http://pubs.acs.org/doi/abs/10.1021/jf00001a032, accessed Jan 2015
Cooley, Jami RN, CNWC. D-Limonene – Effective for Lowering Cholesterol Naturally and Much More. Natural Health Advisory Daily, Jun 2013. Available http://www.naturalhealthadvisory.com/daily/cholesterol-control/d-limonene-%E2%80%93-effective-for-lowering-cholesterol-naturally-and-much-more/, accessed Jan 2015. Link updated to http://universityhealthnews.com/daily/heart-health/d-limonene-effective-for-lowering-cholesterol-naturally-and-much-more/, accessed Aug 2016.
Dweck, Anthony C. Toxicology of Essential Oils Reviewed. Personal Care Asia Pacific, 2009. http://www.zenitech.com/documents/Toxicity_of_essential_oils_p1.pdf
"Lemon Essential Oil". Mountain Rose Herbs website, MRH, OR USA. https://www.mountainroseherbs.com/products/lemon-essential-oil/profile accessed Feb 2015
"Limonene". Encyclopedia Britannica. Available https://www.britannica.com/science/limonene, last accessed Aug 2016
Mondello, Casilli, Tranchida, Costa, Dugo and Dugo. Fast GC for the Analysis of Citrus Oils. Journal of Chromatographic Science, Vol. 42, September 2004. Available http://chromsci.oxfordjournals.org/content/42/8/410.full.pdf, accessed Jan 2015
Pappas, Robert PhD. EOUdb "Lemon (Argentina 1)" through "Lemon 2". Essential Oil University, IN USA, copyright 2015. Available via registration at essentialoil.university, accessed Jan 2015.
Pub Chem, "Beta-Pinene". U.S. National Library of Medicine, PubChem Open Chemistry Database, MD USA. Available http://pubchem.ncbi.nlm.nih.gov/compound/14896?from=summary#section=Top, accessed Jan 2015
Right to Know Hazardous Substance Fact Sheet, "Alpha-Pinene". New Jersey Dept. of Health, NJ USA, Aug 2008. Available http://nj.gov/health/eoh/rtkweb/documents/fs/0052.pdf, accessed Jan 2015
Toxicology Data Network, "Alpha-Pinene". US National Library of Medicine, MD USA. Available http://toxnet.nlm.nih.gov/cgi-bin/sis/search2/f?./temp/~Y6BF33:3, accessed Jan 2015.
Toxicology Data Network, "Lemon Oil". US National Library of Medicine, MD USA. http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+1944 accessed Jan 2015.