FlavScents AInsights Entry for Phenethyl Isobutyrate (CAS: 103-48-0)

1. Identity & Chemical Information

• Common Name(s): Phenethyl isobutyrate
• IUPAC Name: 2-phenylethyl 2-methylpropanoate
• CAS Number: 103-48-0
• FEMA Number: 2865
• Other Identifiers: FL No. 09.271
• Molecular Formula: C12H16O2
• Molecular Weight: 192.26 g/mol

Phenethyl isobutyrate is an ester compound characterized by its phenethyl group linked to an isobutyric acid moiety. The ester functional group contributes to its fruity and floral odor profile, which is significant in both flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Phenethyl isobutyrate is known for its pleasant, fruity, and floral aroma, often described as reminiscent of honey, rose, and tropical fruits. It exhibits a moderate intensity and diffusion, making it suitable as both an impact note and a background modifier in formulations. The compound's odor threshold is relatively low, allowing it to impart noticeable effects even at minimal concentrations.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Phenethyl isobutyrate occurs naturally in various fruits, including apples and strawberries, contributing to their characteristic aromas. It can also be formed through esterification processes involving phenethyl alcohol and isobutyric acid. Its presence in natural sources supports its designation as a "natural flavor" or "natural fragrance" component, depending on the context of its use.

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

4. Use in Flavors

Phenethyl isobutyrate is utilized in a wide range of flavor applications, particularly in fruit-flavored products such as candies, beverages, and desserts. It serves as a flavor enhancer and impact note, providing a sweet, fruity character. Typical use levels in finished food products range from 1 to 10 ppm, with higher concentrations potentially leading to overpowering effects. The compound is generally stable under typical food processing conditions, although it may be susceptible to hydrolysis under extreme pH conditions.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In the fragrance industry, phenethyl isobutyrate is valued for its floral and fruity notes, fitting well within floral, fruity, and gourmand fragrance families. It acts as a modifier and impact note, often used in perfumes, body sprays, and personal care products. Typical concentration ranges in formulations are from 0.1% to 1%, depending on the desired intensity. Its volatility allows it to contribute primarily to the top and middle notes of a fragrance composition.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Recognized as GRAS by FEMA for flavor use.
• European Union: Approved under Regulation (EC) No 1334/2008 with FL No. 09.271.
• United Kingdom: Follows EU regulations post-Brexit.
• Asia: Approved for use in Japan and China, with specific concentration limits.
• Latin America: Generally accepted in Brazil and MERCOSUR countries, subject to local regulations.

Explicit approvals and harmonized assumptions are common, though formulators should verify specific country requirements due to potential variability.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Phenethyl isobutyrate is considered safe for use in food and fragrance applications at typical exposure levels.

• Oral Exposure: No specific ADI is established, but it is generally recognized as safe under FEMA GRAS guidelines.
• Dermal Exposure: Low potential for irritation or sensitization, with IFRA standards providing guidance on safe use levels in fragrances.
• Inhalation Exposure: Volatility suggests minimal risk under normal use conditions, though occupational exposure should be monitored.

Risk profiles are similar across food and fragrance applications, with no significant differences noted.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Phenethyl isobutyrate is prized for its ability to impart a natural, fruity aroma, enhancing the sensory appeal of both flavors and fragrances. It synergizes well with other esters and floral compounds, though care should be taken to avoid overuse, which can lead to an artificial or cloying effect. Formulators often underutilize its potential in complex blends, where it can add depth and realism.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on phenethyl isobutyrate is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, though some regional regulatory nuances may require further verification. Known data gaps are minimal, with most information supported by authoritative sources.

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 2026-02-23 14:38:21 GMT (p2)