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Citrus limon

Lemon oil

Under the IFRA Standards a rinse-off soap may hold up to 20 % of this oil, a limit set by its 7-Methoxycoumarin.

IFRA maximum for soap

20 % at most, of the soap

Restricted constituents, at the typical levels IFRA's annex gives:

Citral
3.5 %
Citronellal
0.1 %
Geraniol
0.1 %
7-Methoxycoumarin
0.05 %

Worked out from typical levels. A supplier's certificate for your lot comes first, and its figure is the one to follow.

Check a blend against its IFRA limits and list its allergens in the fragrance and allergen calculator.

How essential oils behave in soap, and how much to use: Scenting soap.

Identity and labelling

Citrus Limon Peel Oil

Botanical name
Citrus limon
CAS
8008-56-8, 84929-31-7
EC
284-515-8

The EU names this oil itself as a fragrance allergen (Regulation (EU) 2023/1545, Annex III entry 353): it goes on the label by name above 0.01 % in a rinse-off product.

What it is and how it behaves in soap

Lemon oil is pressed from the peel of Citrus limon without heat, mainly in Argentina, Italy, Spain, South Africa, Brazil and the United States (EFSA). It smells exactly like lemon zest, and it is one of the scents that vanish fastest from cold process soap.

Grosso says lemon needs a boost from other citrus or lemon-scented oils and a resin such as benzoin; Fisher blends 85 % lemon with 15 % litsea to anchor it, and a base note such as cedarwood helps too. Cable's recipes use lemon at 0.8 to 1.6 % of the oils. The IFRA figure on this page is the ceiling.

Cold-pressed lemon is phototoxic on skin left in the sun. IFRA restricts it in leave-on products but not in rinse-off soap. Citrus oils go off within months (Cavitch), and oxidised limonene is a potent sensitiser (SCCS), so buy a little at a time and keep it cold.

Recipes that use it

Sources

All essential oils