Tea Tree Oil: A Practical Australian Guide

Tea tree is one of the few genuinely Australian ingredients that went global. The plant grows wild in a fairly small strip of the NSW north coast, and the commercial industry still sits largely in that region.

Which means the bottle in your cupboard probably came from a few hundred kilometres of Australian coastline, regardless of the brand on the front.

What it actually is

Steam-distilled oil from the leaves and terminal branches of Melaleuca alternifolia. Not to be confused with:

• Cajeput or niaouli, which are other Melaleuca species with different oils.
• Manuka oil, from a different plant entirely, mostly New Zealand.
• Tea, which has nothing to do with any of it. The name came from sailors who brewed the leaves.

The important marker on a label is the botanical name. If it says Melaleuca alternifolia, it's tea tree. If it just says "tea tree", check the back.

The terpinen-4-ol number

If you look closely at a good tea tree oil you'll find a percentage on the label or the spec sheet.

Terpinen-4-ol is the main component and the one the international standard is built around. ISO 4730 sets a minimum of 30% terpinen-4-ol and a maximum of 15% cineole. Australian commercial oil typically comes in comfortably above that minimum.

You don't need to memorise it. What it's useful for is comparison: a producer who publishes their terpinen-4-ol figure is telling you they test their oil. One who doesn't, isn't.

How people use it

Almost always diluted, and almost always topically or around the house.

• Diluted in a carrier oil for spot application on skin.
• A few drops in a diffuser, for the smell.
• Added to household cleaning water — a very common Australian habit.
• In shampoos and washes, usually already formulated at a low percentage.
• On laundry, a couple of drops in the wash.

Note the pattern: it goes into something, rather than on you neat.

Using it safely

This is the part that matters more than the uses list, because tea tree oil is potent and widely misused.

• Never swallow it. Tea tree oil is toxic if ingested, including in small amounts. It is for external use only.
• Dilute before skin contact. Typical topical dilution sits around 1–5% in a carrier oil. Neat application causes irritation in a lot of people.
• Patch test first, on the inside of the forearm, and wait 24 hours.
• Keep it away from pets, particularly cats and dogs. Tea tree oil is toxic to them and there are plenty of documented poisonings.
• Store it dark and cool. Oxidised tea tree oil is more irritating than fresh. If yours smells sharp and turpentine-like rather than medicinal, it's old.
• Avoid the eyes, and avoid broken skin unless a product is specifically formulated for it.

If your skin is sensitive or reactive, or you're pregnant, get advice specific to you rather than following a general article.

Buying it

Four things worth checking:

1. Botanical name — Melaleuca alternifolia, printed somewhere.
2. Country of origin. Australian-grown is the benchmark for this oil.
3. Dark glass. Clear bottles let light degrade the oil.
4. A sealed cap and a date. Oxidation is the main quality problem with tea tree.

OGA's tea tree oil is 30ml of pure Australian melaleuca oil in a dark bottle.

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