What does 4-Pentenoic acid, 2-methyl-, ethyl ester do?

Used in cosmetics as a fragrance ingredient.

Is 4-Pentenoic acid, 2-methyl-, ethyl ester safe?

We haven't assessed a concern score for this ingredient yet. It is listed for cosmetic use in the EU.

beauty
industrial

4-Pentenoic acid, 2-methyl-, ethyl ester

CAS 105999-68-6

Also registered as 1 other CAS number

53399-81-8

4-Pentenoic acid, 2-methyl-, ethyl ester chemical structure

Concern score

Not assessed — no hazard data yet.

4-Pentenoic acid, 2-methyl-, ethyl ester in plain language

What it is: On cosmetic ingredient lists it appears as “Ethyl 2-METHYLPENT-4-ENOATE”.
Also known as Ethyl 2-METHYLPENT-4-ENOATE · Ethyl 2-METHYL-4-PENTENOATE · 2-METHYL-4-PENTENOIC acid ethyl ester · AKOS015915881 · Ethyl 2-methyl-4-pentanoate · Ethyl 2-methyl-4-pentenoate, 98%
Show all 9 names
Ethyl 2-methylpent-4-en-1-oate · LMFA07010859 · UNII-F7GX41R904
What it does: Used in cosmetics as a fragrance ingredient.
Perfuming
Fragrance
Flavouring
Is it a concern?: We haven't assessed a concern score for this ingredient yet. It is listed for cosmetic use in the EU.

Regulation

No restrictions found. 4-Pentenoic acid, 2-methyl-, ethyl ester appears in these published regulatory listings.

Recorded in these product areas

Found in consumer products
Industrial

EUCosIngActiveListed in CosIng inventory for cosmetic use.
- Listed in CosIng inventory for cosmetic use.Source →
USEPAcommercial use observedEPA CPDat observed this chemical in 0 composition records across product categories including unclassified products. EPA CPDat classifies this chemical for functional uses including Fragrance, Flavouring and nutrient.
- EPA CPDat observed this chemical in 0 composition records across product categories including unclassified products. EPA CPDat classifies this chemical for functional uses including Fragrance, Flavouring and nutrient.Source →
USFDAlisted in openFDA substanceopenFDA substance registry classifies this ingredient as chemical.
- openFDA substance registry classifies this ingredient as chemical.Source →

Expert safety opinions

No expert opinion on file for 4-Pentenoic acid, 2-methyl-, ethyl ester. These are the independent scientific bodies that assess ingredients like this one; we show an opinion only when a record we hold cites it.

SCCS
EU Scientific Committee on Consumer Safety
No SCCS opinion on file.
CIR
Cosmetic Ingredient Review (US expert panel)
No CIR safety assessment on file.

Evidence & sources

No graded research studies for 4-Pentenoic acid, 2-methyl-, ethyl ester yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.

6 data sources

Where this comes from

CosIng
regulatory · updated 2026-09-23
Open →
EPA Chemical and Products Database
exposure · updated February 8, 2019
Open →
EPA DSSTox Identifiers
chemistry · updated 2025-12-29
Open →
FDA GSRS UNII
registry · updated 2026-02-26
Open →
openFDA Substance
registry · updated 2026-05-24
Open →
PubChem Live Enrichment
chemistry · updated 2026-05-17
Open →

Suitability

Context-specific fit derived from published classifications and the current ingredient evidence profile.

Fragrance avoidance

Not a strong fit for fragrance avoidance because it carries Fragrance.

Avoid

The ingredient itself is a fragrance-linked signal, so it is better treated as an avoid case when fragrance exposure is the main concern.

Where it has been recorded

How often EPA CPDat has listed 4-Pentenoic acid, 2-methyl-, ethyl ester in a product composition. These are source records, not Greenveil catalog products.

Named organisations

Typical roles

PerfumingFragranceFlavouring

See products using 4-Pentenoic acid, 2-methyl-, ethyl ester →