Tea Tree Oil Facts by BBird
TEA TREE OIL FACTS
By BBird
There are a few things we need to know about Tea Tree Oil (Melaleuca alternifolia), aka TTO.
Tea Tree Oil is grown in Australia and is an old aboriginal remedy. It is one of the most scientifically researched essential oils. TTO has the feature of being effective against all three categories of infectious organisms: bacteria, fungi and viruses.(1)(3)
Tea tree oil contains varying amounts of 1,8–cineole, a skin irritant. Products with high amounts of this compound may cause skin irritation or contact dermatitis, an allergic reaction in some individuals. TTO is easily oxidized by exposure to air or heat. Oxidized TTO may trigger allergies more than fresh tea tree oil.(2). Eucalyptus oils also have high amounts of 1,8-cineole.
Tea Tree is a powerful immuno-stimulant.(3) Since an allergic reaction is an immune system response, Tea Tree could increase the magnitude of a reaction by individuals sensitive to any of the components of the oil. (BBird deduction.)
The vast popularity of Tea Tree Oil and the demand for natural "alternative" products has created such a demand for TTO that the oil as found in the global marketplace is often adulterated. Kristen Leigh Bell, in Holistic Aromatherapy for Animals, says, "The mass production of Tea Tree to meet demand has also most surely met with adulteration and poor quality oils, resulting in more adverse reactions and irritation."(4)
My own experience in the production of aromatherapy products, over 10 years, is that the large suppliers of essential oils to commercial manufacturers often provide lesser quality essential oils. Moreover, these suppliers and manufacturers sometimes do not utilize proper storage and handling of essential oils to prevent oxidation and degradation.
What does this mean for the average groomer or pet owner? It means that we must stop buying into the myth that a product with "natural" ingredients is somehow surely safer than something "chemical". Hello! They are ALL chemicals. The principal constituents of TTO are Terpinene-4-ol (up to 30%), cineol, pinene, terpines, cymene, sesquiterpenes, sesquiterpene alcohols, among others.(3) The actual chemical composition of the Tea Tree in our ear cleaner can vary from crop to crop as soil and weather vary. The TTO can also vary according to the distillation process, the storage and handling methods, and whether or not some cheap stuff has been added to increase the volume of product. Compare this to Isopropyl Alcohol 70%. It is almost always the same. It is regulated by law to contain 70% isopropyl alcohol, and the additional ingredients are also specified. (5)
Manufacturers are fueling our fear of chemicals and marketing types are trying to hype us into buying "naturally sourced" products instead of "synthetics". The truth is it is all chemistry and the synthetics are more consistent; their effects and side effects are more established and well-known. Manufacturers who are tossing in naturally sourced ingredients without due regard to the complex chemistry and the more delicate balance of the constituents, and who are not handling naturally sourced substances in a way to prevent oxidation and degradation are being inadvertently irresponsible and simply playing (Cha Ching) on our distrust of chemicals. This distrust has been magnified into full-fledged chemophobia by clever marketing tactics. It is time to get over our fear of chemicals and accept the chemical nature of our world and that all products that we use have some potential for adverse reaction. Natural is not more safe. In my opinion, all products using TTO should have a warning statement to the effect that Tea Tree Oil can be a sensitizer and cause allergic reactions in some individuals.
(1) Ann Berwick, Aromatherapy - A Holistic Guide, Llewellyn Publications, 1998, p.208
(2) Tea Tree Oil: Science and Safety, NCCAM (National Center for Complementary and Alternative Medicine.
http://nccam.nih.gov/health/tea/treeoil.htm
(3) Julia Lawless, Encyclopedia of Essential Oils, Thorsons, 2002., pg. 178
(4) Kristen Leigh Bell, Holistic Aromatherapy for Animals, Findhorn Press, 2002, p.129
(5)Rubbing Alcohol Chemical Composition. http://chemistry.about.com/od/chemicalcomposition/f/What-Are-The-Ingredients-In-Rubbing-Alcohol.htm
Conclusion: In properly diluted, rinse-off shampoos, tea tree oil offers potential benefits for dogs with skin issues due to its antibacterial and antifungal properties. However, undiluted tea tree oil is toxic to dogs, and products must be specifically formulated for canine use. Some experts still recommend caution due to a lack of comprehensive safety and efficacy studies.
2025 Update: Summary of Safety concerns and limitations
Despite potential benefits, the use of tea tree oil in any pet product carries significant risks that require caution.
• Undiluted toxicity: Concentrated, 100% tea tree oil is highly toxic to dogs and can cause severe poisoning, even in small quantities. Symptoms can include tremors, paralysis, vomiting, and coma, and may appear hours after exposure.
• Lack of proven efficacy Some scientists point out that no studies have definitively proven tea tree oil to be more effective for dogs than traditional, proven treatments. However, The concentration required for therapeutic effect may exceed the safe dosage.
• Dosage Note: The studies of Tea Tree Oil (Melaluca official that have given positive results regarding antimicrobial efficacy have utilized full strength (neat) oil. Not the less than 1% (way less) that is used in pet shampoos.
• The common and safe usage percentage of tea tree oil in canine shampoo is 0.1% to 1%. Products are considered non-toxic if they stay below a 1-2% concentration, but pure, undiluted tea tree oil is highly toxic to dogs and should never be used directly on their skin. Is TTO effective at 1%?
• Studies on dandruff in humans all recommended 5% usage.
• No industry regulation: Unlike prescription medication, essential oil products for pets are not regulated, meaning the listed ingredients and concentrations may not be accurate. This makes it difficult for a consumer to fully understand the risks. Pet shampoo consumers have no idea if they are getting a tiny bit or a lot of TTO in a shampoo.
• Risk of ingestion: Dogs may accidentally ingest the oil by licking their fur after a bath, even with a rinse-off product. This is a common cause of toxicity. For cats, TTO can be lethal at just a pinch.
• Allergic Potential: A review of published records in 2020 found that Tea Tree Oil had the most recorded adverse effects of any essential oil studied since 1991. Several of the common chemical constituents found in TTO are well-established allergic sensitizers for humans. As demand and usage of TTO continues to rapidly expand, it is likely that more allergic reactions will come to light.
• Adulteration: The burgeoning demand for essential oils, it is now estimated that 89-85% of essential oils available on the commercial market have been adulterated. TTO is one of the most likely oils to be adulterated. Quality TTO, especially that which is regulated from Australia, is costly and in such large demand that the supply falls short. One of the ways in which TTO is stretched to meet the demand and/or reduce the cost is by the addition of inexpensive Eucalyptus oils which closely match TTO in constituents. Another common means of adulteration is to add vegetable oils. So, are you really getting the good stuff in that doggie shampoo?
• FOOD FOR THOUGHT: Is TTO at risk of becoming the next Aloe Vera?
⁃ By this we refer to the fact that aloe vera is often used more for psychological, marketing value, in quantities far short of what would be effective. Like Aloe Vera, TTO, has become recognizable as a “good thing”and is sometimes found at the bottom of an ingredient panel. This strongly suggests that the ingredient is being used at a very low “fairy dust” amount of .1-.01 percent. Aloe Vera is a substance that the pet owning public, as well as professional groomers want to see as reassurance the product is soothing. Similarly, the public recognizes TTO as antimicrobial and the presence of this ingredient in an ingredient panel likewise offers the consumer reassurance that the product kills germs. Think About IT!
⁃ BTW, some groomers mistakenly believe that Tea Tree Oil is a soothing substance. It is not. On broken or inflamed skin is burns like a sum bich.
• ADDITIONAL REFERENCES - TEA TREE OIL MELALEUCA ALTERNIFOLIA
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• Sindle A, Martin K. Art of Prevention: Essential Oils - Natural Products Not Necessarily Safe. Int J Womens Dermatol. 2020 Nov 12;7(3):304-308. doi: 10.1016/j.ijwd.2020.10.013. PMID: 34222588; PMCID: PMC8243157.
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• In recent years…, the composition of these [essential] oils has been found to be more complex than previously thought. Increased use has led to increasing reports of allergic contact dermatitis (ACD), a delayed-type hypersensitivity reaction to allergens in sensitized individuals. the authors seek to highlight the possibility that natural products may not be necessarily as safe as once thought and in particular seek to highlight allergic contact dermatitis caused by essential oils.
• de Groot AC, Schmidt E. Tea tree oil: contact allergy and chemical composition. Contact Dermatitis. 2016 Sep;75(3):129-43. doi: 10.1111/cod.12591. Epub 2016 May 13. PMID: 27173437.
• Of all essential oils, TTO has caused most (published) allergic reactions since the cases were first reported in 1991. The review suggests fresh TTO is a moderate sensitizer, but oxidation significantly increases its allergenic potential.