Tea Tree Oil

Tea Tree oil can boast of supreme antibiotic powers. It is lauded for its antibacterial effects, even against some infections that we seem to have become powerless against because of antimicrobial resistance. It can use to minimize acne pimples. And it has proved better than regular medication against acne because it causes fewer side effects. It is also beneficial to treat common wounds because of its antiseptic properties. Aromatherapy massage using tea tree oil has the potential to relieve sore, tense muscles. Its aroma is not just medicinal pine-like with camphoraceous notes; it also exerts therapeutic effects. Diffusing tea tree oil can lower the chances of fungal infections like ringworms. As more research comes in, we believe that it may also have the potential to boost memory and reduce the risk of transmission of tuberculosis.

Source

Essential oil is expressed (produced) by a process known as steam distillation. Fresh leaves of the Melaleuca alternifolia, the Tea tree plant, are used. They are fragrant, and their antibacterial and antiseptic properties were known to the original inhabitants of Australia, the Aborigines. When colonial settlers came to know of its properties, it rapidly became a staple in medicinal treatments. Presently, it is unrivalled among essential oils for its widespread use.

In the past, only wild plants were used to extract the essential oil. As oil demand has multiplied manifold, the plant is being cultivated in a commercial nature.

Colour and Aroma

Tea tree oil has a clear appearance. Its colour is white, albeit slightly milky. But it is not opaque or murky. Its aroma resembles turpentine and camphor. But that is not all. It has mild hints of spice and citrus. This unique concoction of aromas lends the oil its medicinal yet refreshing feel. Some people may be able to discern an aroma similar to eucalyptus essential oil. This is because it contains a compound called eucalyptol which is also found in eucalyptus essential oil. Congratulations, you have an incredible sense of smell!

Properties

• Antibacterial – Tea tree essential oil has a strong killing effect on a broad spectrum of bacteria. It is effective against common yet dangerous disease-causing organisms like E. coli, S. aureus and P. acnes.
• Antifungal – It kills many species of the candida family of fungi, some of which cause candidiasis, better known as thrush. It also heals ringworms because it kills dermatophytic fungi that cause these itchy infections.
• Anti-viral – It exhibits potency against the HSV-1 herpes virus, making it helpful as a home remedy for cold sores.
• Antiseptic – Its amazing antibacterial, antifungal and anti-viral powers make it a useful antiseptic. It is being used in medical studies as wound dressings to promote faster and complete healing.
• Anti-inflammatory – It has verified inflammation-reducing effects, which is helpful because its calms redness, swelling and pain in conditions like acne or rheumatoid arthritis when applied to the skin.

It is to be borne in mind that although tea tree oil is such a powerful antibacterial, we cannot make full use of this information. Because tea tree oil is strictly meant only for topical use. one should NOT consume it internally.

Health Benefits and Uses

Acne

Tea Tree oil improves acne verifiably. Numerous medical studies have documented the ameliorative effect that it has on mild and moderate acne. Usually, when we look up medical studies about a natural ingredient for a specific purpose, the medical community is not always unanimous. But in the case of tea tree oil, research papers concur that tea tree oil helps acne.

Acne is a complex reaction of the body to hormonal and environmental stressors. In many cases, it is a natural response that can only be subdued but not eliminated. What we do know is that acne is inextricably linked to male and female reproductive hormones. It is very common in adolescents and young adults because of the surging hormones. But other forces are acting too. Acne may be exacerbated or perhaps even directly caused by a bacterial infection of oil-secreting glands located just beneath the hair follicles. This bacterium is P. acnes. Natural substances that act against P. acnes have been found to reduce the severity of acne. Secondly, the infection may be activating the immune system. When our immune defences are engaged, we also experience inflammation. That is the reason behind swelling, redness, pain and burning sensation caused by acne pimples.

Tea Tree oil aids in this condition because it is potent antibacterial against the P. acnes bacterium, and it is also an anti-inflammatory in minute concentrations. But if the strength of tea tree oil in the salve, solution or gel, is too high, it can lead to counter-irritation. Some people have even experienced chemical burns!

A medical study compared the effect of tea tree oil versus benzoyl peroxide (BP). BP is given to kill bacteria and peel off the outer layer of skin. The study found that a 5% solution of tea tree oil was as effective as BP in reducing the number of active acne pimples (comedones). Tea tree oil showed a lag in action, which means that you would have to wait a week or so before the preliminary results begin to show. Most importantly, they found that tea tree oil caused minimal side effects that accompany standard acne treatment like excessive drying of the facial skin, peeling or burning sensations. The redness subsided upon three months of consistent use. Itching also calmed down, which may have helped manage the irresistible desire to poke and scratch at the pimples. [1]

A more recent study made a formulation combining bee propolis (natural glue used by bees in their hives), aloe vera and tea tree oil. They tested the efficacy of their formulation against a commonly prescribed antibiotic. Not surprisingly, the natural trio performed better at moderate acne than the drug. This was confirmed through photographic evidence. The total number of lesions (pimples) reduced, and even the severity of the acne subsided. [2] what kept the concentration of tea tree oil in the entire gel at 3%. This means that for 100 grams of the gel, tea tree oil made up only Three grams. One gram of a standard essential oil is usually made up of 20 drops. So that makes up 60 drops for 100 grams of total gel. We can use this arithmetic to our advantage in designing natural homemade remedy for acne.

Our natural remedy for moderate acne is simpler. It requires tea tree oil (100% pure) and jojoba oil (cold-pressed and organic). To 100 ml of jojoba oil, add 60 drops of tea tree oil while counting carefully. Close the bottle’s lid (it should be an amber-tinted glass bottle) and then shake it gently so that the essential oil dissolves in the base oil. Every day after sunset, cleanse the face thoroughly. A salicylic acid containing face wash is often recommended for acne. Take a clean cotton pad and pour few drops of the mixture onto it. Gently rub it into the acne pimples and the surrounding area. Tea tree oil can make the pimples sting a little bit. But it will not sting a lot if the strength of tea tree oil is at or below 3%. Do not wash off the oil yet; let it sit.

After 2 or 3 hours, the face should be washed off when the dinner has been taken. As a nighttime moisturizer, plain old Aloe Vera gel is excellent. It cools and soothes the skin like no other natural substance. Aloe Vera is not just a powerful hydrator of the skin; it also minimizes inflammation. An additional benefit would be toning up of the skin because of the healing effect of Aloe Vera. It contains a natural compound called glucomannan which acts to improve the collagen matrix inside our skin. It is this matrix of collagen and elastin that forms the structure of the skin. As we age, decay of collagen and elastin causes the characteristic sagging accompanied by ageing.

Tea tree oil is being suggested online as a regular skincare regimen for people with oily or combination skin. Although it is true that tea tree oil dries out the skin but using it as a regular regimen is not advisable. Tea tree oil is quite harsh and can sensitize the skin. This may aggravate inflammation instead of reducing it. As of now, it is better to use it only for specific conditions, like acne, until peer-reviewed research validates its utility as a long term skincare ingredient.

Cold Sores

These are painful sores that occur near the edges of lips. They are often accompanied by fevers, which is why the name fever blisters. The body goes through a flu-like state. The HSV-1 virus causes them. This is very closely related to the HSV-2 virus, which notoriously causes genital herpes. It is due to the similarity of viruses that even cold sores are viewed with suspicion. Cold sores often resolve on their own, but we can try specific remedies to speed up the healing process. Many essential oils have powerful anti-viral properties. A case in point is the essential oil of lemon balm (Melissa officinalis). It has a powerful killing effect on cold sores. But if lemon balm essential oil is not lying around the house, tea tree oil would be the next best thing. Numerous studies attest to the virus killing effect of tea tree oil. [3]

Tea tree oil can be applied topically onto cold sore but only after proper dilution. First, we need to choose a suitable carrier oil. This will carry the tea tree oil into the skin cells. For cold sores, coconut oil is a good choice. Coconut oil spreads well and is gentle on the skin. And it has a pleasant aroma. If it touches our lips, it doesn’t feel bitter or unpalatable. Take 10 ml of virgin coconut oil and add six drops of tea tree essential oil. This makes for a 3% solution. Now, these two should be mixed and kept in a glass bottle. A few drops of this oil are to be applied to the cold sore as a spot treatment.

It is advised to use tea tree oil-based treatment only once per day. This safeguard is necessary because tea tree oil, being an essential oil, can be harsh on our skin. It should apply after the sun has set because tea tree oil may make the skin overly sensitive to sunlight (photosensitive).

Ringworm Infection

Ringworm infections are very common. They can occur almost anywhere on the skin but most commonly infect the groin, feet, waist and scalp. There seems to be a link with sweat accumulation. For example, when we wear socks and shoes all day long, it can increase the chances of catching an athlete’s foot, which is also a kind of ringworm infection. Similarly, sweat may accumulate near the waistband, especially if it is a tight fit. Living in hot and humid climatic regions also increases the risk of these infections. Ringworms are usually easy to identify as they are reddish, almost circular rashes with a raised edge. They cause itching, which can become unbearably discomforting. Ringworms are also highly contagious, so it is also vital that we treat them early.

In the past, ringworms used to be treated with X-rays and all other kinds of technologies. Later on, who discovered antifungal medication, and they have been quite effective. Doctors usually prescribe antifungal dusting powders or creams for ringworms. But now we are noticing a disturbing trend. The fungi responsible for the various types of ringworms (like the dermatophytes) have started to show signs of resistance to medication. This poses a risk for humanity and animal life because, in the very near future, there is a real risk that fungi will learn to evade the medicine completely. One answer to this genuine concern is a natural medication. There are numerous herbs, edible oils and essential oils that show powerful antifungal action against fungi. Tea tree oil shows effectiveness in killing fungi species. In medical studies, it killed Trichophyton mentagrophytes (responsible for ringworm), T. rubrum (can cause athlete’s foot, ringworm of the groin, nail fungal infections and other ringworms), T. tonsurans (ringworm of the scalp). [4]

How to use tea tree oil on ringworm?

One should never apply tea tree oil neat on any part of the skin. It is incredibly strong and harsh and will most certainly cause a chemical burn. It must be diluted. In the case of ringworm, the ideal choice of carrier oil (the one in which we shall dissolve tea tree oil) is coconut oil. It is best to use virgin coconut oil, but if you live in a cold climate where coconut oil solidifies at room temperature, who can use fractionated coconut oil.

Tea tree oil kills fungi responsible for ringworm at minimum inhibitory concentrations not above 0.5%. We get this from lab tests. This means that if a formulation has just 0.5% tea tree oil, it would effectively eradicate ringworm. We can devise a simple home remedy using this information. We know that 20 drops of any essential oil from a standard dropper comprise 1 mL. We shall take 100 ml of coconut oil. We only need to add 0.5mL of tea tree oil, which means ten drops of tea tree oil in the 100 mL of coconut oil. This mixture should be tested first on healthy skin as a patch test. Then one can apply it to the ringworm. We can use this remedy against athlete’s foot, nail fungal infection and scalp ringworm. However, one should not use it against jock itch because the skin of our genitalia is quite sensitive, and an essential oil does pose a risk of sensitizing it. In the case of a jock itch, virgin coconut oil is more suitable as it is gentle on the skin.

If tea tree oil does not lead to sensitivity or discomfort, then this remedy should be continued. It often takes ringworm more than a week to clear up. Even after it has cleared up, tea tree oil-based remedy should be applied for one more week to eliminate any chance of some fungi remaining alive. In total, one may have to apply it for 3 to 4 weeks.

If your skin tolerates tea tree oil favourably, the concentration of tea tree oil in this remedy can be increased from 0.5% to 5%, which is ten times stronger. A study conducted to evaluate the safety of tea tree essential oil when applied topically came up with the conclusion that tea tree oil does not cause adverse reactions (most commonly contact dermatitis) even at 10% strength. [5] We are taking a safer route and suggesting a maximum of 5% only. Although the lower strength solution works against ringworm, it may take a longer time or may not lead to a complete cure, only alleviation of symptoms. A higher concentration has a greater chance of leading to complete treatment. [6]

Dandruff

Tea tree oil is one of the most authentic natural treatments for dandruff. In a widely cited medical study, a shampoo containing 5% tea tree oil led to the significant reduction of dandruff in both men and women. Not only were dandruff flakes reduced, but they also lowered itching and greasiness. What is even more important is that there were no adverse reactions. The study highlighted that the efficacy of tea tree oil against dandruff is possible because of its killing action against a fungus known as Pityrosporum ovale, also known as Malassezia furfur. [7]

Some people try to formulate a hybrid shampoo by adding essential oil directly to any shampoo. However, this is fraught with danger. Shampoos are different in their chemistry and action. They have a wide array of chemicals, mostly synthesized in the lab but some obtained from natural sources. Since we do not know how tea tree oil’s monoterpenes, sesquiterpenes, and other aromatic compounds react with the shampoo compounds, one should not mix tea tree oil into any shampoo. It is suggested to buy a product that already has tea tree oil in it. Reputed shampoo manufacturers do chemical analysis, and their product must pass tests to ensure that there are no toxic or carcinogenic products.

Some preliminary studies suggest that tea tree oil-containing shampoo may also turn out to be applicable in seborrheic dermatitis. However, we do not have as conclusive studies as there are for its use in dandruff. Seborrheic dermatitis is a much more aggressive and persistent infection by the same fungi that causes dandruff. In some cases, if dandruff is left untreated for months on end, it can take the form of seborrheic dermatitis. Secondly, dandruff seems to be linked to thinning of individual hair shafts and to diffuse hair loss. That is why dandruff should not be neglected.

Chronic Gingivitis

In this condition, gums become inflamed. They become sensitive and often bleed when brushing is done. There seems to be a link to bacterial infection at the plaques accumulated on and between our teeth. The gums become visibly swollen and painful. Tea Tree oil can be made use of to subside inflammation that causes gingivitis.

In a study carried out with 49 participants (both men and women), a gel containing 2.5% Tea tree oil helped reduce bleeding and inflammation in gums. It was not effective at cleansing off the plaques. This led researchers to conclude that although cleaning using a toothbrush twice daily is an utmost priority, tea tree oil-containing gel can serve an additional helping hand. [8]

It is difficult to make oil in water emulsion type gel at home. It is manufactured in pharmaceutical firms. It requires natural cellulose polymers and equipment to mix cellulosic material with water and add tea tree oil. Further, it must be sterilized by heating and many other processes, which is complex.

What we can go for is oil in oil solution. Tea Tree oil dissolves in coconut oil. 40 to 50 drops of tea tree oil are added to 100 ml of virgin coconut oil. Then it must be stirred to stimulate the dissolution. Once the tea tree oil is dissolved, the home remedy is ready. Take a few drops of this oil onto the index finger and massage gently into the gums after brushing teeth. Tea tree oil causes a stinging, burning sensation when it encounters a bleeding cut or bruise.

In another prominent and in-depth study, tea tree oil-based gel was studied to alleviate some symptoms of periodontitis. This is a much more severe condition in which gum inflammation has permeated deeper to affect the roots and support teeth structure. It is much more persistent, more painful, and a matter of serious concern. The study contrasted standard treatment for this condition with standard treatment plus daily tea tree oil-based gel application. It was found that the tea tree oil group had a reduced level of an inflammation marker known as PTX-3. This is significant because it clearly shows that tea tree oil reduces inflammation at the level of blood flow. This means that the negative effects of a gum infection would not lead to serious health problems in other parts of the body. In our body, if one region is undergoing infection, inflammation indicators are high within the blood because our immune systems are trying desperately to clear off the infection. If inflammation signals remain elevated for months or years, they may themselves lead to other more severe conditions like heart disease and rheumatoid arthritis.

Wound Healing

Medical studies are revealing that tea tree oil acts as a fantastic antiseptic for wound dressings. Its powerful antibacterial action protects open wounds from such dangerous infections as E. coli and S. aureus. More than half of the participants who applied a tea tree oil-based gel saw their wound contract in size in one study. However, the infection was not wiped off completely. This study used a 3% strength. A later study used a 10% Tea tree oil strength gel on wounds infected by the deadly MRSA (methicillin-resistant staph infection). Not only was the infection eliminated, but wounds also closed up fully. [9] This is very motivational and uplifting for the medical community because they have found natural cures for antibiotic-resistant infections.

Essential oils have distinct advantages over antibiotic creams and wound washing liquids. Bacteria and other pathogens have learnt to devise resistance against modern medication. Still, they cannot hide from the onslaught of natural compounds, most notably volatile compounds in essential oils.

Although tea tree oil is now being used in many patented formulations for wounds and burns, we should not follow this argument and use it on wounds directly at home. Any essential oil, when used neat, can cause severe chemical burns. In wounds, we cannot formulate a home remedy because it is not easy to make an oil-in-water gel formulation. We can make oil-in-oil solutions, like tea tree oil in coconut oil. But these are not suitable for wound dressings. The problem occurs because tea tree oil does not dissolve in water. It is heartening to find that creams and liquids are being made and sold using natural ingredients so that slowly but steadily, we reduce the risk of antibiotic resistance among us and our future generations. In wound treatment, some encouraging studies are going on, revealing that honey is also a powerful wound-healing substance.

Aromatherapy

Tea tree oil reduces the risk of catching some infections when it is diffused into the air. This has been proved for fungal infections. Tea tree oil would be quite helpful for people who live a physically active, hectic and demanding lifestyle. Its pine and camphor-like cooling aroma mixed with hints of citrus and spice are useful for activating the mind and getting some work done. It contains alpha-pinene, which aids in cognitive tasks and memory recollection.

Aromatherapists have been using it as a pain reliever in aromatherapy massage. And there is a scientific basis for this usage. Tea tree oil exerts anti-inflammatory effects when it gets absorbed into our blood through the skin. Only one precaution need to be taken. The strength of tea tree oil should not exceed 5 to 10%. Beyond this strength, we are risking contact dermatitis. That said, aromatherapy massage is a great way to ease muscle strain and mental fatigue because it addresses both the physiological and psychological aspects. Often, strain builds up in our muscles due to stress on our mind and how our posture changes due to it. For example, many of us tend to arch our shoulders and tense up the back muscles when short pressed for time.

It is important to note that although tea tree oil feels cooling first, it’s after effect is warming. This is the nature of all essential oils that resemble spice in the aroma. It has a healing touch, which is excellent for changing from the tropical or boreal aroma.

You can create a blend by mixing it with oregano and essential pine oils and a few drops of lemon or bergamot to add a citrus touch. Chamomile and lavender essential oils can be said if it feels too warming. It blends well with lavender essential oil, and they both exhibit synergy.

Word of caution: Avoid using warming essential oils like tea tree oil in the diffuser in the summer months if you live in tropical and sub-tropical climates.

Chemical Composition

Tea tree oil is among the most widely sold essential oils in terms of total market volume. That is why International Standards Organisation has formed internationally acceptable quality standards. If a tea tree oil product has an ISO certified mark, it is up to standards and an authentic product. This makes life so much easier for consumers because buying pure and authentic essential oil can be a hassle.

ISO has specified the range of chemical constituents and their minimum and maximum values. These are mentioned in the table below.

Volatile constituent	Type	Composition
Terpinen-4-ol	Monoterpene alcohol	35 – 48%
Gamma terpinene	monoterpene	14 – 28%
Alpha terpinene	monoterpene	6 – 12%
1,8 – cineole	Monoterpene alcohol	Traces – 10%
Terpinolene	monoterpene	1.5 – 5%
Alpha terpineol	Monoterpene alcohol	2 – 5%
p-cymene	monoterpene	0.5 – 8%
Alpha pinene	monoterpene	1 – 4%
Sabinene	monoterpene	Traces – 3.5%
Limonene	monoterpene	0.5 – 1.5%
aromadendrene	sesquiterpene	0.2 – 3%
Ledene (syn. Viridiflorene)	sesquiterpene	0.1 – 3%
Globulol	Sesquiterpene alcohol	Traces – 1%
viridiflorol	sesquiterpenoid	Traces – 1%

We can see that a significant portion of the essential oil is made up of monoterpene and its derivatives. This chemical profile is that of tea tree oil of a specific type, known as Melaleuca alternifolia chemotype terpinen-4-ol because this compound dominates it. However, other chemotypes are rich in 1,8 – cineole and others that are rich in terpinolene. There are some claims that chemotype terpine-4-ol is the best variety of tea tree oil in terms of health benefits, but as for now, these claims are unfounded.

Terpinen-4-ol being the most abundant volatile compound, brings to the table potent anti-inflammatory activity. It suppresses the expression of inflammatory cytokines. Cytokines are a type of proteins that are secreted majorly by our immune system when it is activated. Some of these cytokines convey to other cells of our body that inflammation must be raked up. Prominent examples are TNF-alpha, Interleukin 1beta, Interleukin 8 and 10. Terpinen-4-ol also suppresses prostaglandin 2 (PGE-2). PGE2 is known to modulate inflammation. These inflammation signalling molecules are instrumental in flaring up inflammation in almost all diseases and conditions, ranging from heart disease, diabetes, rheumatoid arthritis, autoimmune disorders, neurodegenerative diseases, ulcerative colitis and other conditions ending in “itis”. At present, we cannot avail of this anti-inflammatory benefit to a greater extent because tea tree oil should not be ingested.

1,8 cineole is also of great interest. It is commonly known as eucalyptol as it is a predominant constituent of Eucalyptus globulus essential oil. It is potent at suppressing and even treating certain respiratory infections. It has remarkable antibacterial properties. Eucalyptol is used as an ingredient in mouthwash and capsules put in a vaporizer to inhale when you get a cold or cough. Since tea tree oil has an appreciable amount of eucalyptol, it can be assumed that it would also be helpful in cold and bronchitis. This needs to be verified by research.

Alpha terpinene and gamma-terpinene play a role as antioxidants. Besides this, they don’t seem to exert any more medicinal effect that we know of yet. Alpha pinene is noteworthy for its effects on memory. It has been known to boost memory function by interfering with cholinergic neurons. Inhaling aroma laden with alpha-pinene is helpful for memory, concentration and learning. Plus, its turpentine like aroma is medicinal and cleansing. Although the amount of alpha-pinene in tea tree oil is not high, it might still exert its cognitive effects.

Viridiflorol is a sesquiterpene class molecule that is capable of inhibiting the bacteria that causes tuberculosis. [11] Further studies can reveal if diffusion of tea tree oil using a diffuser can prohibit the spread of tuberculosis. This molecule could have an incredibly beneficial role to play in reducing the burden of tuberculosis in high incidence countries and regions. Tuberculosis is one of those infections that are so contagious that they cannot remain isolated. They can easily cause pandemics. We would need to be ready with advanced medication based on natural substances that do not create antimicrobial resistance.

It is quite possible that the spectrum of verified health benefits that we attribute to tea tree oil could well be widened as more compelling research comes in. We shall have to wait and see.

Side Effects and Toxicity

Tea tree oil is a harsh essential oil. It poses a severe risk of causing contact dermatitis even if a minute amount, like a single drop, is used neat. It should ALWAYS be diluted in a carrier oil. In formulations that include oil in water type gels, tea tree oil is safely tolerated by us up to 10%. A medical study has established this. [4] But it is suggested to start with a lower strength if your skin is sensitive. Another major problem is that of stale oil. If tea tree oil is kept for months or even years on the shelf, it gets oxidized, and many of its useful active constituents have by then changed into potent irritants. It is imperative to buy tea tree oil in small quantities and store it properly, away from heat and light. Most of the contact dermatitis cases are reported to have been caused by the stale essential oil. [11]

Tea tree oil should NEVER be ingested. There have been cases of poisoning of children and some adults when they drank tea tree oil. It should be kept in such a place that it is out of reach of infants and kids. Pregnant women and lactating mothers should avoid tea tree oil. It should not even be used in minor amounts to treat infections because we do not know if it interferes with foetus development. In lactating mothers, tea tree oil compounds may be reaching the infant through breastfeeding, which is not safe. [12]

Tea tree oil is toxic to cats to dogs. A prominent pet toxin helpline warns that one should never use it neat on a dog or a cat. [13] Although there are no reported cases of human death from exposure to undiluted tea tree oil, there have been many cases where dog or cat have succumbed to tea tree oil poisoning. It is suggested that in some rare cases, up to 1% tea tree oil-based products can be used topically on dogs. But in our opinion, tea tree oil should not be used on or in the vicinity of cats and dogs at all. For example, do not use tea tree oil to drive off fleas from your dog. Their metabolism process is quite different from ours, and especially the younger ones may not be able to filter out the volatile organic compounds that make up an essential oil.

Buying and Storage

Tea tree oil is still a costly essential oil even though tea tree is being grown commercially on large plantations in eastern Australia. It is essential to buy from a reputed manufacturer having decades of experience in distilling, storing and transporting essential oils. Many cheaper products on the market may not be 100% tea tree oil and may have been pre-diluted with edible vegetable oils. Firms that are willing to share chemical analysis of their tea tree oil done using the sophisticated GC-MS analysis are more likely to be trusted by prospective consumers. Tea tree oil that matches ISO standards as certified by a third-party laboratory is authentic.

An essential oil should not be stored in plastic containers. The volatile organic constituents of essential oils react with and degrade the plastic. Ideally, they should be stored in thick glass vials that are made airtight through a snug fit cork made of wood. It is traditional but scientifically effective. Tea tree oil does not have a comfortable shelf life, and in hot and humid conditions, it may oxidize in just six months. In colder climates, it may run well for twi2 years. It is recommended to keep it in the refrigerator.

References

1. A comparative study of tea-tree oil versus benzoyl peroxide in the treatment of acne. Bassett et al., Med J Aust. 1990 Oct 15;153(8):455-8
2. Treatment of acne with a combination of propolis, tea tree oil, and Aloe vera compared to erythromycin cream: two double-blind investigations. Mazzarello V. et al, Clinical Pharmacology, 2018; 10: 175–181.
3. Anti-viral activity of Australian tea tree oil and eucalyptus oil against herpes simplex virus in cell culture. Schnitzler P. et al, Pharmazie. 2001 Apr;56(4):343-7.
4. Melaleuca alternifolia (Tea Tree) Oil: a Review of Antimicrobial and Other Medicinal Properties. C.F. Carson et al., Clin Microbiol Rev. 2006 Jan; 19(1): 50–62.
5. 13 – Essential oil profiles. Robert Tisserand and Rodney Young, Essential Oil Safety (Second Edition)
6. Treatment of interdigital tinea pedis with 25% and 50% tea tree oil solution: a randomized, placebo-controlled, blinded study. Satchell A.C. et al., Australas J Dermatol. 2002 Aug;43(3):175-8.
7. Treatment of dandruff with 5% tea tree oil shampoo. Satchell A.C. et al., J Am Acad Dermatol. 2002 Dec;47(6):852-5.
8. The effects of a tea tree oil-containing gel on plaque and chronic gingivitis. Soukoulis S. and Hirsh R. et al, Aust Dent J. 2004 Jun;49(2):78-83.
9. Treatment Strategies for Infected Wounds. Irina Negut et al, Molecules. 2018 Sep; 23(9): 2392.
10. ISO Standards, https://www.sis.se/api/document/preview/921469
11. Chemical variation in the essential leaf oil of Melaleuca quinquenervia (Cav.) S.T. Blake. B.F.Ireland et al., Biochemical Systems and Ecology, Volume 30, Issue 5, May 2002, Pages 457-470
12. A comparative study of antibacterial and anti-inflammatory effects of mouthrinse containing tea tree oil. Salvatori C. et al, Oral Implantol (Rome). 2017 Jan-Mar; 10(1): 59–70.
13. https://www.petpoisonhelpline.com/poison/tea-tree-oil/
14. Site Link