FlavScents AInsights Entry for Propionaldehyde (CAS: 123-38-6)

1. Identity & Chemical Information

Propionaldehyde, also known as propanal, is a simple aldehyde with the CAS number 123-38-6. Its IUPAC name is propanal, and it is recognized by FEMA with the number 2930. The molecular formula for propionaldehyde is C3H6O, and it has a molecular weight of 58.08 g/mol. This compound features an aldehyde functional group, which is crucial for its characteristic odor profile. The presence of the carbonyl group (C=O) in aldehydes is often associated with pungent, penetrating odors, which are significant in both flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Propionaldehyde is characterized by a sharp, pungent odor reminiscent of green, fruity notes with a hint of nuttiness. It is often described as having a penetrating and somewhat acrid aroma, which can be perceived at low concentrations. The compound's odor threshold is relatively low, making it a potent impact note in formulations. In flavor applications, propionaldehyde can contribute to the authenticity of fruit flavors, particularly in apple and citrus profiles, where it adds a fresh, green nuance.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Propionaldehyde occurs naturally in various fruits and essential oils. It can be formed through the oxidative degradation of fatty acids and is also a byproduct of fermentation processes. In the context of natural flavors, propionaldehyde can be considered a natural component when derived from these sources. Its presence in natural matrices supports its use in "natural flavor" designations, provided it is sourced appropriately.

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

4. Use in Flavors

In flavor applications, propionaldehyde is used to enhance fruit flavors, particularly apple, citrus, and berry profiles. It serves as an impact note, providing a fresh, green, and slightly nutty character. Typical use levels in finished food products range from 0.1 to 5 ppm, depending on the desired intensity and the complexity of the flavor system. Propionaldehyde is relatively stable under acidic conditions but may degrade under high heat or oxidative environments, necessitating careful formulation considerations.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

Propionaldehyde is utilized in fragrance formulations to impart a fresh, green note that can enhance the realism of floral and fruity compositions. It is commonly found in the top notes of perfumes, where its volatility contributes to the initial impression of the fragrance. Typical concentrations in fragrance products are low, often below 0.1%, due to its potent odor. Its role as a modifier or impact note is crucial in creating vibrant, fresh accords.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

In the United States, propionaldehyde is recognized as GRAS (Generally Recognized As Safe) by FEMA for flavor use. In the European Union, it is regulated under Regulation (EC) No 1334/2008 and has an assigned FL number. The regulatory status in the UK aligns with the EU post-Brexit. In Asia, including Japan and China, propionaldehyde is permitted for use in flavors, though specific concentration limits may vary. In Latin America, countries like Brazil follow MERCOSUR regulations, which generally align with international standards.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Propionaldehyde's safety profile varies with exposure route. For oral exposure in flavor use, it is considered safe at low concentrations, with an acceptable daily intake (ADI) not clearly reported but generally low due to its potent nature. Dermal exposure in fragrance use may cause irritation or sensitization, necessitating adherence to IFRA guidelines. Inhalation exposure, relevant in occupational settings, requires adequate ventilation due to its volatility and potential respiratory irritation.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Propionaldehyde is valued for its ability to impart fresh, green notes in both flavors and fragrances. It synergizes well with other aldehydes and esters, enhancing fruity and floral profiles. Formulators should be cautious of its volatility and potential for oxidation, which can alter its sensory characteristics. It is often under-used due to its potent nature, but when balanced correctly, it can significantly enhance product authenticity.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on propionaldehyde is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, though specific use levels may vary by application. Some data gaps exist in precise toxicological thresholds, but general safety is 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

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 2026-11-12 18:27:21 GMT (p2)