Pelargonic Acid

Also known as: Nonanoic Acid

INCI: Pelargonic Acid | Function: Antimicrobial, Fragrance, pH Adjuster | Type: Fatty Acid (C9)

What Is Pelargonic Acid?

Pelargonic Acid (nonanoic acid) is a 9-carbon saturated fatty acid that occurs naturally in pelargonium (geranium) oil and other plants. It has demonstrated antimicrobial and antifungal properties, making it useful as a natural preservation aid in cosmetic formulations. It is also used as a fragrance component and pH adjuster.

Key Skin Benefits

+ Broad-spectrum antimicrobial — effective against bacteria and fungi
+ Natural preservation — supports hurdle technology preservation systems
+ pH adjustment — mild organic acid helps balance formulation pH
+ Fragrance — contributes subtle green/floral notes

Pros

+ Naturally occurring — found in geranium and other plants
+ Multifunctional — antimicrobial + pH adjustment + fragrance
+ Biodegradable short-chain fatty acid
+ Compatible with natural and organic formulations

Cons

− Can be irritating at high concentrations (>2%)
− Odor may require masking in some formulations
− Limited standalone preservative efficacy — use in combination

Specifications

Property	Value
Usage Areas	Face, Body, Hair
Product Type	Leave-On, Rinse-Off
Source	Plant / Synthetic
Natural Level	Natural-derived

Safety Ratings

Metric	Rating
Skin Sensitivity	2/5
Comedogenic Rating	0-1/5
EWG Score	1/10

Regional Regulatory Limits

Region	Leave-on %	Rinse-off %	Status
EU (CosIng)	No limit	No limit	Allowed
US (CIR/FDA)	No limit	No limit	Allowed
Japan (MHLW)	No limit	No limit	Allowed
ASEAN	No limit	No limit	Allowed
China (NMPA)	No limit	No limit	Allowed

Typical Usage % by Product Type

Product Type	Typical %
Natural deodorant	0.5 - 2%
Preservation booster	0.1 - 0.5%
Fragrance component	0.01 - 0.1%

References

CosIng (2025) — Pelargonic Acid, INCI function: antimicrobial, perfuming. https://ec.europa.eu/growth/tools-databases/cosing/
EWG Skin Deep — Pelargonic Acid score 1. https://www.ewg.org/skindeep/
PubChem — Nonanoic Acid (CID 8158). https://pubchem.ncbi.nlm.nih.gov/
SpecialChem — Pelargonic Acid cosmetic uses. https://cosmetics.specialchem.com/

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