Dilute it to around 1–5% in a carrier oil before skin contact, patch test on the forearm and wait 24 hours, never swallow it, and keep it away from cats and dogs. Tea tree oil is a concentrated essential oil, not a gentle one.
Tea tree oil has a reputation as the harmless natural option, which is exactly why it gets misused. It's a concentrated plant extract and it deserves the same care as anything else in the cupboard with a warning label.
None of this is complicated. It's just rarely spelled out.
Dilution: the actual numbers
Neat tea tree oil on skin irritates a lot of people, and repeated neat use is a common way to develop sensitivity to it.
Typical topical dilutions:
| Use | Dilution | In 10ml carrier |
|---|---|---|
| Face or sensitive areas | 1% | 2–3 drops |
| General body use | 2–3% | 4–9 drops |
| Small spot application | 5% | 15 drops |
Carrier oils that work: jojoba, sweet almond, coconut (fractionated), grapeseed. Water is not a carrier — oil and water separate, and you'll end up applying neat oil.
How to patch test properly
Most people skip this or do it wrong.
- Mix at the dilution you plan to actually use.
- Apply a small amount to the inside of the forearm.
- Leave it uncovered and don't wash the area.
- Wait 24 hours. Contact reactions frequently take hours to appear, so a five-minute check tells you nothing.
- Any redness, itching or bumps — don't use it.
If you've reacted to tea tree oil before, don't retest at a lower dilution hoping for a different answer. Sensitisation tends to persist.
Never swallow it
This is the one that matters most.
Tea tree oil is toxic if ingested, including in small quantities, and children are most at risk. Symptoms of ingestion can include drowsiness, confusion and loss of coordination.
- Store it out of reach and out of sight, ideally locked.
- Buy bottles with child-resistant caps.
- Don't decant it into unlabelled containers.
- Never add it to food, drinks or homemade "wellness" preparations.
If someone swallows tea tree oil, call the Poisons Information Centre on 13 11 26 immediately. In an emergency call 000.
Pets
Tea tree oil is toxic to cats and dogs, both applied to skin and if licked off. Cats are especially vulnerable because of how they metabolise these compounds, and they groom whatever lands on them.
- Don't apply it to pets unless a vet has specifically directed it.
- Don't use it in a diffuser in a room a pet can't leave.
- Keep the bottle where a curious dog can't get it.
- Wash your hands before handling a pet after using it.
Signs of exposure in a pet include wobbliness, drooling, tremors and lethargy. That's a vet call, not a wait-and-see.
Oxidation, and why old oil is worse
Tea tree oil oxidises on contact with air, light and heat. Oxidised oil is significantly more irritating than fresh — most reported skin reactions involve oil that has degraded.
- Keep it in dark glass, tightly closed, away from heat.
- Buy a size you'll actually finish. A 30ml bottle used occasionally will oxidise before it empties.
- If it smells sharp and turpentine-like rather than clean and medicinal, replace it.
Other things to avoid
- Eyes. Rinse with a bland oil rather than water if it gets in, then seek advice.
- Broken or damaged skin, unless a product is specifically formulated for it.
- Pregnancy and breastfeeding — get advice specific to you rather than relying on general information.
- Young children. Get advice before using it on them at all.
- Combining it with other actives on the same patch of skin without knowing how they interact.
The short version
Diluted, patch tested, external only, away from pets and children, stored dark and replaced when it ages. Do those and it's a straightforward thing to have around.
OGA's tea tree oil is 30ml of pure Australian melaleuca oil in a dark bottle.
Frequently asked
How do you dilute tea tree oil? Mix it into a carrier oil such as jojoba, almond or fractionated coconut — around 1% for the face, 2–3% for general body use, up to about 5% for small spot application. Water doesn't work as a carrier.
Can you put tea tree oil on skin undiluted? It's not advised. Neat application irritates many people and repeated neat use is a common route to becoming sensitised to it.
Is tea tree oil safe for cats and dogs? No. It's toxic to both, on the skin and if ingested. Cats are especially vulnerable. Don't apply it to pets or diffuse it in a room they can't leave.
What happens if you swallow tea tree oil? It's toxic if ingested and can cause drowsiness, confusion and loss of coordination. Call the Poisons Information Centre on 13 11 26 immediately, or 000 in an emergency.
How long does tea tree oil last? It oxidises with air, light and heat, and oxidised oil is more irritating than fresh. Keep it in dark glass, closed and cool, and replace it if the smell turns sharp.
How do I patch test tea tree oil? Apply it at your intended dilution to the inside of your forearm, leave it uncovered and unwashed, and wait a full 24 hours. Reactions often take hours to show.
OGA Tea Tree Oil is 30ml of pure Australian melaleuca oil. For external use only. Dilute before applying to skin, keep away from eyes, children and pets, and do not swallow. In case of ingestion call the Poisons Information Centre on 13 11 26. Not intended to diagnose, treat or cure any condition.
