What is the maximum topical dilution for Geranium (bourbon type)?

The adult topical ceiling is 3%, which is 6 drops per 10 ml of carrier oil and 18 drops per 30 ml at 1 ml ≈ 20 drops. For facial use or long-term daily use, drop to 0.5% — 1 drop per 10 ml.

Who should avoid Geranium (bourbon type)?

This site marks no avoid row for this oil, but pregnancy, children and household pets should still follow the applicable row in the matrix below, and a four-step patch test should be completed before first use.

How do I run a skin patch test?

Dilute 1 drop in 5 ml of carrier oil (1%). Apply 2 drops to the inner forearm. Cover for 24 hours. Read at 24 and 48 hours. Geraniol and citronellol are declarable fragrance allergens, so a positive here is not unusual. A positive is redness, itching, burning or blistering; any of those means stop using it.

Geranium (bourbon type) — botanical line drawing and constituent bar

Single-oil monograph

Geranium (Pelargonium graveolens, bourbon type)

Q: What is the shelf life of Geranium (bourbon type) and how does it oxidise?

24 months. Citronellol and geraniol are primary alcohols and oxidise, though more slowly than linalool. The more useful ageing signal here is the isomenthone fraction, which shifts the smell from rose-and-mint toward a flatter, muddier note. Two years is the honest figure for a household bottle.

Pelargonium graveolens

Geranium (bourbon type) · Geraniaceae · leaf

Chemotype Citronellol / geraniol type

Phototoxic No phototoxicity
Pregnancy Caution
Pets Caution

Published 2026-09-06 · adult ceiling 3% · shelf life 24 months

By The Aroma Desk

Geranium is the affordable stand-in for rose, and it carries the same allergen exposure. Citronellol and geraniol together are 46% of this oil, and both are on the EU list of fragrance allergens that must be declared in leave-on cosmetics above 0.001% — a threshold far below any useful dilution. This monograph covers what that actually means for a home blender.

01 · Dose

Safe dilution matrix

Rows are the concentration, columns are the audience. Each cell carries two lines: drops per 10 ml of carrier oil, and whether this site advises that combination. Figures come from 1 ml = 20 drops, and the bold row is the ceiling for this oil.

Geranium (bourbon type) · Pelargonium graveolens
Dilution	Per 30 ml	Adult	Child 6+	Pregnancy	Pets
0.5%	3	1 drops ✓ advised	1 drops ✓ advised	1 drops ✓ advised	1 drops ✓ advised
1%	6	2 drops ✓ advised	2 drops ✓ advised	2 drops ✗ not advised	2 drops ✗ not advised
2%	12	4 drops ✓ advised	4 drops ✗ not advised	4 drops ✗ not advised	4 drops ✗ not advised
3%	18	6 drops ✓ advised	6 drops ✗ not advised	6 drops ✗ not advised	6 drops ✗ not advised

What each concentration is normally for: 0.5% — Facial blends, sensitive or broken skin, children 6-15, first patch test · 1% — Everyday adult body and massage blends, daily leave-on use · 2% — Short-term localised adult use, 7 to 10 days then re-assess · 3% — Adult ceiling for robust oils, small area, short course only

02 · Contraindications

Contraindications & handling

✓ no restriction · ! caution · ✗ avoid. An avoid row means choosing a different material, not lowering the concentration.

! Pregnancy & breastfeeding — caution
! Children under 16 — caution
! Households with pets — caution
✓ Epilepsy — ok
✓ Antihypertensive medication — ok
✓ Anticoagulant medication — ok

Four-step skin patch test

Dilute 1 drop in 5 ml of carrier oil (1%).
Apply 2 drops to the inner forearm.
Cover for 24 hours.
Read at 24 and 48 hours. Geraniol and citronellol are declarable fragrance allergens, so a positive here is not unusual.

03 · Botany

Botanical record

Family: Geraniaceae · Geraniaceae
Botanical part: leaf
Extraction: steam-distillation
Origin: Egypt, China, Reunion (bourbon), Morocco
Chemotype: Citronellol / geraniol type
Phototoxicity: No phototoxicity
Shelf life: 24 months

Principal constituents

Citronellol 30%
Geraniol 16%
Citronellyl formate 9%
Linalool 8%
Isomenthone 6%
Guaia-6 3%

Storage & oxidation

Citronellol and geraniol are primary alcohols and oxidise, though more slowly than linalool. The more useful ageing signal here is the isomenthone fraction, which shifts the smell from rose-and-mint toward a flatter, muddier note. Two years is the honest figure for a household bottle.

04 · Rotation

Rotation & substitution

Geranium, rose, palmarosa and citronella all lean on the same two alcohols. Rotating between them is not a real rotation — it is the same exposure with a different label. Pair geranium with a wood or a resin instead: cedarwood, sandalwood, frankincense.

Adjacent materials

Palmarosa (Cymbopogon martinii)

Geraniol-dominant at 70-85% for a fraction of the price. Same allergen family

Rose geranium (Pelargonium capitatum x radens)

A different Pelargonium

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