FlavScents AInsights Entry: Isobutyl Alcohol (CAS: 78-83-1)

1. Identity & Chemical Information

• Common Name(s): Isobutyl alcohol, 2-Methyl-1-propanol
• IUPAC Name: 2-Methylpropan-1-ol
• CAS Number: 78-83-1
• FEMA Number: 2178
• Other Identifiers: FL No. 02.002, CoE No. 145
• Molecular Formula: C4H10O
• Molecular Weight: 74.12 g/mol

Isobutyl alcohol is a primary alcohol with a branched structure, featuring a methyl group attached to the second carbon of the propanol chain. This structural configuration contributes to its characteristic odor profile, which is often described as fruity and slightly alcoholic. The presence of the hydroxyl group is crucial for its solubility in water and its reactivity in esterification reactions, which are important in flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Isobutyl alcohol is known for its distinctive odor, which is often described as fruity, sweet, and slightly alcoholic. It has a moderate intensity and is commonly used as a background note in flavor compositions. The odor threshold of isobutyl alcohol is relatively low, allowing it to impart noticeable effects even at minimal concentrations. In flavor systems, it is typically used to enhance the perception of fruitiness and to add complexity to alcoholic beverage profiles.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Isobutyl alcohol occurs naturally in various fruits and fermented products. It is formed through the fermentation process, where yeast metabolizes sugars to produce alcohols, including isobutyl alcohol. This compound is also a byproduct of the Maillard reaction, which occurs during the cooking and processing of foods, contributing to the development of complex flavors. Its presence in natural sources qualifies it for use in "natural flavor" designations under certain regulatory frameworks.

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

4. Use in Flavors

Isobutyl alcohol is utilized in a variety of flavor categories, including fruit, alcoholic beverages, and confectionery. It serves as a functional component that enhances fruitiness and provides a realistic alcoholic note. Typical use levels in finished food or beverage products range from 1 to 50 ppm, with higher concentrations used in more robust flavor profiles. It is generally stable under typical food processing conditions, although it may be susceptible to oxidation if not properly stored.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In the fragrance industry, isobutyl alcohol is used across several fragrance families, including floral, fruity, and green compositions. It acts as a modifier and impact note, providing a fresh, sweet, and slightly alcoholic aroma. Typical concentration ranges in fragrance formulations are from trace amounts up to 1%, depending on the desired effect. Isobutyl alcohol is volatile and primarily contributes to the top 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. 02.002.
• United Kingdom: Follows EU regulations post-Brexit with no significant divergence reported.
• Asia: Approved for use in Japan and China, with specific concentration limits in certain applications.
• Latin America: Generally accepted in Brazil and MERCOSUR countries, with harmonized regulations aligning with international standards.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Isobutyl alcohol is considered safe for use in food and fragrance applications when used within established guidelines. For oral exposure, it has a high margin of safety with no specific ADI established, but typical use levels are well below any toxicological concern. Dermal exposure in fragrance applications is generally safe, with low potential for irritation or sensitization. Inhalation exposure is minimal due to its low volatility, but occupational exposure limits should be observed in manufacturing settings.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Isobutyl alcohol is valued for its ability to enhance fruitiness and provide a realistic alcoholic note in both flavors and fragrances. It synergizes well with esters and other alcohols, creating complex and appealing profiles. Formulators should be cautious of its volatility and potential for oxidation, ensuring proper storage conditions. It is often underutilized in non-alcoholic applications where its subtle effects can enhance overall product appeal.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on isobutyl alcohol is well-established, with comprehensive documentation available from authoritative sources. Industry practices are consistent with documented guidelines, although some regional regulatory nuances may exist. No significant data gaps or ambiguities are noted, providing a high level of confidence in its safe use.

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 2026-04-06 19:53:22 GMT (p2)