AInsights Entry for Isoamyl Alcohol (CAS: 123-51-3)
1. Identity & Chemical Information
- Common Name(s): Isoamyl alcohol, Isopentyl alcohol
- IUPAC Name: 3-Methylbutan-1-ol
- CAS Number: 123-51-3
- FEMA Number: 2059
- Other Identifiers: FL No. 02.015
- Molecular Formula: C5H12O
- Molecular Weight: 88.15 g/mol
Isoamyl alcohol is a primary alcohol with a branched structure, characterized by a hydroxyl group (-OH) attached to a carbon atom that is part of a branched alkyl chain. This structure contributes to its distinctive odor profile, which is often described as fusel-like or reminiscent of ripe bananas. 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
Isoamyl alcohol is known for its strong, pungent odor, often described as fusel-like, with fruity notes reminiscent of bananas and pears. It is a key component in the aroma of certain alcoholic beverages, contributing to their characteristic bouquet. The intensity of its odor is moderate to strong, and it has a relatively high diffusion rate, making it noticeable even at low concentrations. While specific taste and odor thresholds are not well-documented, it is generally recognized as having a low threshold, meaning it can be detected at low concentrations.
In flavor systems, isoamyl alcohol serves as an impact note, providing a fruity, banana-like character that can enhance the overall profile of a product. It is often used in conjunction with other esters and alcohols to create complex, realistic fruit flavors.
Citation hooks: FlavScents; peer-reviewed sensory literature
3. Natural Occurrence & Formation
Isoamyl alcohol occurs naturally in various fruits and is a byproduct of fermentation processes. It is commonly found in alcoholic beverages such as whiskey and beer, where it is produced during the fermentation of sugars by yeast. The formation of isoamyl alcohol in these contexts is typically through the Ehrlich pathway, where amino acids are converted into fusel alcohols by yeast.
Its presence in natural sources qualifies it for use in products labeled as containing "natural flavors." However, the concentration and impact can vary significantly depending on the source and processing methods.
Citation hooks: FlavScents; food chemistry literature; EFSA/JECFA monographs
4. Use in Flavors
Isoamyl alcohol is widely used in the flavor industry, particularly in fruit flavors such as banana, pear, and apple. It acts as a key component in creating authentic fruit profiles and is often used in conjunction with esters like isoamyl acetate to enhance its fruity character. Typical use levels in finished food and beverage products range from 1 to 50 ppm, with higher concentrations potentially leading to off-flavors due to its fusel-like character.
Stability considerations include its moderate volatility and susceptibility to oxidation, which can alter its sensory profile. It is generally stable under acidic conditions but may degrade under high heat or prolonged exposure to air.
Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature
5. Use in Fragrances
In the fragrance industry, isoamyl alcohol is used in various fragrance families, including fruity, floral, and gourmand compositions. It serves as a modifier, adding depth and realism to fragrance blends. Typical concentration ranges in perfumes and personal care products are from trace amounts up to 0.5%, depending on the desired intensity and character.
Isoamyl alcohol contributes primarily to the top and middle notes of a fragrance, providing an initial burst of fruitiness that transitions into a more subtle, lingering aroma. Its volatility is moderate, allowing it to blend well with other fragrance components.
Citation hooks: FlavScents; IFRA; fragrance chemistry texts
6. Regulatory Status (Regional Overview)
United States
Isoamyl alcohol is generally recognized as safe (GRAS) by FEMA for use in food flavors. It is approved for use in alcoholic beverages and other food products.
European Union
Under Regulation (EC) No 1334/2008, isoamyl alcohol is approved for use as a flavoring substance. It is listed with the FL number 02.015.
United Kingdom
Post-Brexit, the UK has aligned with EU regulations regarding flavoring substances, maintaining similar approvals for isoamyl alcohol.
Asia
In Japan, isoamyl alcohol is permitted for use in food flavors, while in China and ASEAN countries, it is subject to specific national regulations that generally align with international standards.
Latin America
Countries like Brazil and those in MERCOSUR follow similar guidelines to the US and EU, allowing the use of isoamyl alcohol in food and beverage applications.
Citation hooks: FEMA; EFSA; national authority publications
7. Toxicology, Safety & Exposure Considerations
Oral Exposure
Isoamyl alcohol has a low acute toxicity profile when ingested, with an acceptable daily intake (ADI) not clearly established but considered safe at typical use levels in food. The threshold of toxicological concern (TTC) and margin of safety are generally favorable, supporting its use in flavor applications.
Dermal Exposure
In fragrance applications, isoamyl alcohol is not a primary irritant or sensitizer, but it can cause mild irritation in sensitive individuals. It is included in IFRA standards with specific usage guidelines to minimize potential dermal reactions.
Inhalation Exposure
Due to its volatility, inhalation exposure is possible, particularly in occupational settings. However, it is not considered a significant inhalation hazard at typical use concentrations in consumer products.
Citation hooks: EFSA; FEMA; PubChem; toxicology literature
8. Practical Insights for Formulators
Isoamyl alcohol is valued for its ability to impart a natural, fruity character to both flavors and fragrances. It synergizes well with esters and other alcohols, enhancing the overall complexity of formulations. Common pitfalls include overuse, which can lead to an overpowering fusel note, and instability in formulations exposed to high heat or air.
Formulators often use isoamyl alcohol in conjunction with stabilizers or antioxidants to preserve its sensory qualities. It is frequently under-utilized in non-fruit applications, where it can add unexpected depth and interest.
Citation hooks: FlavScents; industry practice
9. Confidence & Data Quality Notes
The data on isoamyl alcohol is well-established, with comprehensive documentation available from authoritative sources such as FEMA and EFSA. Industry practices are well-documented, though some variability exists in use levels and sensory descriptions. Known data gaps include specific ADI values and detailed sensory thresholds, which are typically addressed through industry-typical estimates.
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 2026-03-16 15:30:49 GMT (p2)
