Isobutyl Benzoate
AKA “120-50-3, 2-Methylpropyl benzoate, BENZOIC ACID, 2-METHYLPROPYL ESTER, Benzoic acid, isobutyl ester, FEMA No. 2185, KQ6XZ9WJII, DTXSID6047074, NSC-6580, DTXCID4027074”
Preservative
Ingredient Facts
Isobutyl benzoate
AKA: 120-50-3, 2-Methylpropyl benzoate, BENZOIC ACID, 2-METHYLPROPYL ESTER, Benzoic acid, Isobutyl ester, FEMA No. 2185, KQ6XZ9WJII, DTXSID6047074, NSC-6580, DTXCID4027074
Preservative · Preservative · EWG: 4
Synthetic
Preservative
Solvent
Not Clean
Isobutyl benzoate is a benzoate ester obtained by the formal condensation of benzoic acid with isobutanol. It has a role as a metabolite. It is functionally related to a benzoic acid and an isobutanol.
Solubility insoluble in water; soluble in organic solvents, oils
Formula
C11H14O2
Mol. Weight
178.23
CAS #
120-50-3
Form
Liquid
State
colourless oily liquid with a green, floral, leafy odour
See origin →
Functions
Preservative
Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.
Solvent
Dissolves other ingredients so they distribute evenly in the formula. Often the invisible "base" everything else is mixed into.
Moisturizing
Antioxidant
Prevents microbial growth
Provides scent
Dissolves other ingredients
Traditional Use
A synthetic ester created through 20th-century organic chemistry synthesis. Employed in cosmetics as an emollient and solvent, particularly in nail products and fragrance formulations.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not Phototoxic
medical-approval
all-shades-safe
Concentration Guide
0.5%
0%1%
Reg. Limit
EU regulatory limit: 0.5%. Source: EU Cosmetics Regulation (EC) 1223/2009, Annex V (Preservatives), Entry 1a.
Regulatory Agencies
Update to RIFM fragrance ingredient safety assessment, isobutyl benzoate, CAS registry number 120-50-3.
Api AM, Bartlett A, Belsito D, Botelho D, Bruze M et al.
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2024
Benzyl Alcohol, Benzoic Acid, Sodium Benzoate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Safety Assessment of Benzyl Alcohol, Benzoic Acid and its Salts, and Benzyl Benzoate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
4-Hydroxybenzoic acid rescues multisystemic disease and perinatal lethality in a mouse model of mitochondrial disease.
Corral-Sarasa J, Martínez-Gálvez JM, González-García P, Wendling O, Jiménez-Sánchez L et al.
Cell reports, 2024
4-Hydroxybenzoic Acid
European Commission
EU Cosmetic Ingredient Database (CosIng)
Isobutyl Benzoate
European Commission
EU Cosmetic Ingredient Database (CosIng)
Benzoic acid and its derivatives as naturally occurring compounds in foods and as additives: Uses, exposure, and controversy.
Del Olmo A, Calzada J, Nuñez M
Critical reviews in food science and nutrition, 2017
Benzoic acid and its derivatives as naturally occurring compounds in foods and as additives: Uses, exposure, and controversy.
Del Olmo A, Calzada J, Nuñez M
Critical reviews in food science and nutrition, 2017
Benzoic acid and its derivatives as naturally occurring compounds in foods and as additives: Uses, exposure, and controversy.
Del Olmo A, Calzada J, Nuñez M
Critical reviews in food science and nutrition, 2017
4-Hydroxybenzoic Acid
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Benzoic Acid
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Safety Assessment of Benzyl Alcohol, Benzoic Acid and its...
Wilbur Johnson, Wilma F Bergfeld, Donald V Belsito, Ronald A Hill, Curtis D Klaassen, Daniel C Liebler + 5 more
International journal of toxicology, 2017
Safety Assessment of Benzyl Alcohol, Benzoic Acid and its...
Wilbur Johnson, Wilma F Bergfeld, Donald V Belsito, Ronald A Hill, Curtis D Klaassen, Daniel C Liebler + 5 more
International journal of toxicology, 2017
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR