Botanical names Melaleuca alternifolia
Source Leaves
Family Myrtaceae
Origin China
Processing Method Steam Distillation
Description / Color / Consistency A thin, clear, pale yellow liquid.
Aromatic Summary / Note / Strength of Aroma A middle note with a medium aroma, Tee Tree has a fresh, slightly medicinal scent with characteristic woody, camphoraceous notes.
Blends With Cinnamon Bark, Clary Sage, Clove Bud, Geranium, Lavender, Lemon, Nutmeg, Rosewood, Rosemary and Thyme.
Product Abstract
Tea Tree oil, also known as Leptospermum petersonii or Melaleuca oil, is one of the most widely used and extensively researched essential oils, making it a must-have for every home. Because the benefits of Tea Tree lemon oil include cleansing properties and a refreshing scent, this versatile oil can be used for everything from home cleaning solutions to skin care.
Keep a bottle of Tea Tree lemon essential oil in your house to make homemade household cleaners, air fresheners, and linen spritzers. You can also find Tea Tree oil uses in your personal care and beauty routine.
History
1770, Captain James Cook landed at Botany Bay, Australia – near where Sydney is now. From there, he traveled north through the coastal regions of New South Wales. During this trek, he and his crew noticed the massive groves of trees thick with sticky, aromatic leaves.
The local natives told him about the healing powers of these trees. The leaves of this tea tree had been used for many years, by these people, to treat cuts and wounds. Crushed leaves were applied directly to an injury, then held in place with a mud pack. This poultice helped fight infection in the wound.
Harvesting/Extraction Information
Unlike the name suggests, the essential oil of tea tree is not extracted from the plant commonly associated with tea as a beverage. Neither is it related to tea oil, which is extracted from the seed of the tea plant. Instead, it is extracted through steam distillation of twigs and leaves of tea tree, which has the botanical name Leptospermum petersonii. The tea tree is native to Southeast Queensland and New South Wales, in Australia, which is why it is such a popular essential oil in that country. However, its impressive qualities have spread to other parts of the world, so it can now be found internationally.
Common usage
Caution
Although there are no inherent risks of topically applying tea tree oil, in some rare cases, people may be overly sensitive to the oil, as a form of a minor allergenic. Melaleuca oil is clearly a powerful cleansing agent for better health, but should not be directly consumed. This is meant as a topical agent, and should not be trusted as an antibacterial agent for oral consumption. As with any new herbal remedy being added to your health regimen, speak to a trained medical professional before making any major changes. The side effects of cionsuming tea tree essential oil can be quite serious, and they include confusion, hallucinations, drowsiness, coma, unsteadiness, severe rashes, vomiting, diarrhea, general weakness, stomach upset, and blood cell abnormalities. It should always be kept away from pets and children.
Key constituents
Terpinen-4-ol 32.0–49.0%
g-Terpinene 11.0–28.0%
1,8-Cineole tr–16.01%
a-Terpinene 6.0–14.0%
a-Terpineol 1.6–9.0%
p-Cymeme 0.6–7.0%
a-Pinene 1.2–5.0%
Terpinolene 1.6–4.0%
Sabinene tr–4.3%
(þ)-Aromadendrene tr–4.0%
d-Cadinene tr–3.0%
Ledene (viridiflorene) tr–3.0%
(þ)-Limonene 0.7–1.4%
Globulol tr–2.0%
Viridiflorol tr–1.0%
Quality Tea tree oil also contains 0–0.06% methyleugenol. The following comments were made in an EU report: ‘The stability of tea tree oil in cosmetic formulations is questionable. A standardized method for the specification of tea tree oil is needed. Industry should develop an analytical testingmethodbasedon typical degradationproducts to ensure and control the stability of the material.’ Since then, an RIRDC report has addressed these issues.
Safety summary
Hazards Skin sensitization.
Cautions Old or oxidized oils should be avoided.
Maximum dermal use level 15%
Our safety advice
Whether for clinical use or in personal care products, a safe and effective concentration of unoxidized tea tree oil is likely to be in the 10–20% range. Therefore, we propose a 15% maximum. Oxidation of tea tree oil should be avoided by storage in a dark, airtight container in a refrigerator. The addition of an antioxidant to preparations containing it is recommended. Undiluted tea tree oil should not be used on the skin, because of the risk of sensitization.
Regulatory guidelines
Tea tree oil is classed as a ‘Schedule 6’ poison in Australia. Substances in this category are regarded as having ‘a moderate potential for causing harm, the extent of which can be reduced through the use of distinctive packaging with strong warnings and safety directions on the label.’ The recommended warnings, to keep out of reach of children and to not take internally, are used by many manufacturers on all their essential oil packaging. However, the recommended use of child-resistant closures on tea tree and other essential oils is not widely adhered to outside of Australia. Although tea tree oil is not restricted in cosmetics in the EU, it is no longer permitted as an ingredient in products making insect repellent claims.
Organ-specific effects
Adverse skin reactions, irritation Some irritation was noted when undiluted tea tree oil was applied to rabbits in an acute dermal LD50 test, and to hairless mice for phototoxicity assessment. When a 25% concentration of tea tree
oil in liquid paraffin was applied to the shaved skin of rabbits for 30 days, there were no visible signs of irritation, but some superficial skin changes were apparent on microscopic examination.
Adverse skin reactions, sensitization To test for sensitization, guinea pigs were given intradermal injections of tea tree oil, and challenged with a further application after two weeks. No potential for sensitization was noted. Tea tree oil was not sensitizing when tested at 1% on 22 volunteers. In a multicenter study in Germany and Austria, 5% tea tree oil tested positive in 1.1% dermatitis patients. Results showed great regional variations with, for example, 0% in Berlin and Vienna, 1.1% in Essen and 2.3% in Dortmund. In a Danish study, one of 217 consecutive dermatitis patients tested positive to 10% tea tree oil, and none of 160 to 5% tea tree oil.
Adverse skin reactions, phototoxicity Undiluted tea tree oil was not phototoxic when applied to hairless mice.
Mucous membrane sensitivity In a clinical trial, there were no adverse reactions to a 2.5% tea tree oil gel applied twice daily with a toothbrush, in 16 patients with severe gingivitis. In a 4 week clinical trial for AIDS patients with oropharyngeal candidiasis, 8 of 12 who used an alcohol-based tea tree solution experienced mild to moderate oral burning, as did 2 of 13 who used an alcohol-free tea tree preparation.
Ocular toxicity A weekly eyelid scrub with 50% tea tree oil was therapeutic in 10 of 11 patients with ocular Demodex, reducing conjunctivitis in most cases, but three patients experienced irritation.
Auditory toxicity In a study of ear toxicity, tea tree oil was applied to the middle ear of guinea pigs. After 30 minutes of instillation, 100% tea tree oil resulted in signs of toxicity to the cochlea. However, when 2% tea tree oil in saline with 0.5% surfactant (Tween-80) was instilled for the same period, there was no lasting threshold change.
Reproductive toxicity There is one report of a 10-year-old boy who developed gynecomastia that resolved after he had discontinued regular use of a shampoo and styling gel, both containing tea tree oil. The products used are not
named, but a subsequent website report alleges that they were manufactured by Paul Mitchell, and were analyzed by a competitor.
Systemic effects
Comments
The Consultant360 site carries a report published on July 1 2007, by Stonehouse and Studdiford, who make the claim
that ‘allergic contact dermatitis has been reported in about 5% of those who use tea tree oil’. However no substantive evidence is, nor could be, given to support this misleading statement.
Dermal application Undiluted tea tree oil was irritating to rabbits and mice, but its irritancy to healthy human skin is negligible. In six clinical trials using tea tree oil at either 5% or 10%, there were no allergic reactions among 295 patients, 67 of them with an inflammatory skin condition.
Ingestion There are insufficient data to establish a safe maximum oral human dose, which has led some to suggest that the oil is not safe to ingest at all. When taken orally in doses of 0.8 mL/kg or more, equivalent to over 50 mL in an adult, tree oil has notable CNS effects, as cited above under Acute toxicity, human.
Species The ISO standard allows that tea tree oil may be obtained from Melaleuca species other than M. alternifolia,
“provided that the oil obtained conforms to the requirements given in this International Standard”. The composition of
M. dissitiflora and M. linariifolia may be very similar to that of M. alternifolia. However, the Australian Tea Tree Industry Association is not aware of any commercial oil production from these species, and there is no safety information on these oils, such as methyleugenol content. We therefore do not consider them viable sources of tea tree oil. Six chemotypes exist for M. alternifolia, although only the terpinen-4-ol chemotype is cultivated on a commercial scale.
Of the other five, one is dominated by terpinolene, and the others are all cineole-rich, with varying concentrations of
other constituents.