FlavScents AInsights Entry for Acetaldehyde (CAS: 75-07-0)

1. Identity & Chemical Information

• Common Name(s): Acetaldehyde
• IUPAC Name: Ethanal
• CAS Number: 75-07-0
• FEMA Number: 2003
• Other Identifiers: FL No. 02.001
• Molecular Formula: C₂H₄O
• Molecular Weight: 44.05 g/mol
• Functional Groups and Structure–Odor Relevance: Acetaldehyde is an aldehyde with a carbonyl group (C=O) that contributes to its pungent, fruity odor. This functional group is crucial for its reactivity and sensory characteristics, making it a significant impact compound in both flavors and fragrances.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Acetaldehyde is characterized by a sharp, pungent odor with fruity and green notes, often described as apple-like. It has a high diffusion rate, contributing to its role as a top note in fragrance compositions. The taste threshold for acetaldehyde is relatively low, making it a potent flavoring agent. It is commonly used as an impact note in flavor formulations to impart freshness and enhance fruit profiles.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Acetaldehyde occurs naturally in various fruits, such as apples and grapes, and is a byproduct of fermentation processes. It is also formed during the Maillard reaction, contributing to the flavor profile of baked goods and roasted foods. Its presence in natural sources allows it to be designated as a "natural flavor" under certain regulatory frameworks.

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

4. Use in Flavors

Acetaldehyde is widely used in flavor formulations, particularly in fruit flavors like apple, citrus, and berry. It serves as an impact note, providing freshness and enhancing the overall flavor profile. Typical use levels in finished food products range from 1 to 50 ppm, with higher concentrations used in more robust flavor systems. Acetaldehyde is sensitive to oxidation and should be stabilized in formulations to maintain its sensory properties.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrances, acetaldehyde is used primarily in the creation of fresh, fruity top notes. It is found in various fragrance families, including citrus and green compositions. Its volatility makes it suitable for top note applications, where it provides an initial burst of freshness. Typical concentrations in fragrance formulations are low, often less than 0.1%, due to its potent odor.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Acetaldehyde is recognized as GRAS (Generally Recognized As Safe) by FEMA for flavor use.
• European Union: Listed under Regulation (EC) No 1334/2008 with FL No. 02.001.
• United Kingdom: Post-Brexit regulations align with EU standards.
• Asia: Approved for use in Japan and China, with specific concentration limits.
• Latin America: Generally accepted in MERCOSUR countries, with adherence to local regulations.

Explicit approvals and harmonized assumptions are common, though country-specific variability exists, particularly in Asia.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: Acetaldehyde has a low acute toxicity profile, with an ADI not clearly established. It is generally considered safe at typical flavor use levels.
• Dermal Exposure: Limited data on skin irritation and sensitization; however, its volatility reduces dermal exposure risk in fragrance applications.
• Inhalation Exposure: High volatility necessitates caution in occupational settings to prevent respiratory irritation.

Risk profiles differ between food and fragrance applications, with inhalation being a primary concern in fragrance use.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Acetaldehyde is valued for its ability to impart freshness and enhance fruit profiles in both flavors and fragrances. It synergizes well with other aldehydes and esters. Formulators should be cautious of its reactivity and potential for oxidation, which can lead to off-notes. It is often under-used in complex formulations due to stability concerns.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on acetaldehyde is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, though some variability exists in regional regulatory interpretations. Known data gaps include specific ADI values and detailed dermal exposure studies.

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 2026-09-03 15:32:12 GMT (p2)