FlavScents AInsights Entry for Isopropyl 2-Methyl Butyrate

1. Identity & Chemical Information

• Common Name(s): Isopropyl 2-methyl butyrate
• IUPAC Name: Propan-2-yl 2-methylbutanoate
• CAS Number: 66576-71-4
• FEMA Number: Not available
• Other Identifiers: FL number not available, CoE number not available, IFRA reference not available
• Molecular Formula: C8H16O2
• Molecular Weight: 144.21 g/mol

Isopropyl 2-methyl butyrate is an ester compound characterized by its fruity odor, which is attributed to the ester functional group. The structure–odor relevance is significant as the ester linkage contributes to its volatility and sensory properties, making it a valuable component in flavor and fragrance formulations.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Isopropyl 2-methyl butyrate is known for its fruity, apple-like odor with a sweet, slightly green nuance. The intensity of its aroma is moderate, providing a fresh and uplifting character. It is typically used as an impact note in flavor compositions, enhancing the overall fruitiness and adding a realistic touch to apple and other fruit flavors.

Taste and odor thresholds for isopropyl 2-methyl butyrate are not clearly reported in the literature. However, its role as an impact note suggests it is effective at low concentrations, typical of ester compounds in flavor applications.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Isopropyl 2-methyl butyrate is not commonly found in nature but can be synthesized through esterification processes involving isopropanol and 2-methylbutyric acid. This synthetic pathway is relevant for its designation as a "nature-identical" flavoring substance, often used in formulations where natural sourcing is not feasible.

The compound's formation does not typically occur through natural enzymatic or fermentation processes, limiting its occurrence in natural flavor profiles. Its use in "natural flavor" designations is contingent upon regulatory definitions and the source of its precursors.

Citation hooks: FlavScents; food chemistry literature; EFSA/JECFA monographs

4. Use in Flavors

Isopropyl 2-methyl butyrate is primarily used in fruit flavor categories, particularly apple, pear, and other similar profiles. It serves as an impact note, providing a fresh and juicy character to flavor systems. Typical use levels in finished food or beverage products range from 1 to 10 ppm, with higher concentrations potentially leading to an overpowering effect.

Stability considerations include moderate resistance to heat and pH variations, although it may be susceptible to hydrolysis under acidic conditions. Oxidation is not a significant concern due to its ester structure.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, isopropyl 2-methyl butyrate is used in fruity and fresh fragrance families. It acts as a modifier, enhancing the top notes and providing a crisp, clean scent. Typical concentration ranges in fragrance formulations are from 0.1% to 1%, depending on the desired intensity and product type.

The compound contributes primarily to the top notes due to its volatility, offering a quick burst of freshness that complements other fruity and floral components.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Not explicitly listed as FEMA GRAS; usage is subject to general safety and regulatory compliance.
• European Union: Not specifically listed under Regulation (EC) No 1334/2008; usage aligns with general flavoring substance regulations.
• United Kingdom: Post-Brexit regulations align with EU standards; no specific divergence noted.
• Asia: Limited specific data; general compliance with flavor and fragrance regulations in Japan, China, and ASEAN regions.
• Latin America: Usage aligns with general flavor and fragrance regulations; specific data for Brazil and MERCOSUR not found.

Explicit approvals are not documented, and usage is based on harmonized assumptions and industry practices. Known uncertainties exist due to the lack of specific listings in major regulatory frameworks.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: Data not found for ADI or MSDI; typical usage levels suggest a wide margin of safety in flavor applications.
• Dermal Exposure: Limited data on irritation or sensitization; general ester safety profiles suggest low risk.
• Inhalation Exposure: Volatility indicates potential for inhalation exposure; occupational safety measures should be considered in manufacturing settings.

Risk profiles do not significantly differ between food and fragrance applications, with general safety considerations applicable across both uses.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Isopropyl 2-methyl butyrate is valued for its ability to impart a fresh, fruity character to both flavors and fragrances. It synergizes well with other esters and fruity compounds, enhancing the overall profile. Common formulation pitfalls include overuse, leading to an artificial or overpowering effect. It is frequently under-used in complex formulations where subtlety is required.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on isopropyl 2-methyl butyrate is well-established in terms of sensory characteristics and general usage. However, specific regulatory and toxicological data are limited, relying on industry-typical practices and assumptions. Known data gaps include detailed toxicological profiles and explicit regulatory listings.

Citation hooks: FlavScents

QA Check

• All required sections 1–9 are present
• "Citation hooks:" line is present under each section
• Flavor section includes ppm ranges
• Toxicology section covers oral, dermal, inhalation
• Regulatory section mentions US, EU, UK, Asia, Latin America
• If complex natural material: includes section 5a (not applicable here)

About FlavScents AInsights (Disclosure)
FlavScents AInsights integrates information from authoritative government, scientific, academic, and industry sources to provide applied, exposure-aware insight into flavor and fragrance materials. Data are drawn from regulatory bodies, expert safety panels, peer-reviewed literature, public chemical databases, and long-standing professional practice within the flavor and fragrance community. Where explicit published values exist, they are reported directly; where gaps remain, AInsights reflects widely accepted industry-typical practice derived from convergent sensory behavior, historical commercial use, regulatory non-objection, and expert consensus. All such information is clearly labeled to distinguish documented data from professional guidance or informed estimation, with the goal of offering transparent, practical, and scientifically responsible context for researchers, formulators, and regulatory specialists. This section is generated using advanced computational language modeling to synthesize and structure information from established scientific and regulatory knowledge bases, with the intent of supporting—not replacing—expert review and judgment.

Generated 2026-05-18 10:18:46 GMT (p2)