FlavScents AInsights Entry: Onion Oil (CAS: 8002-72-0)

1. Identity & Chemical Information

Onion oil is a natural complex material derived from the Allium cepa plant, commonly known as onion. It is classified under CAS number 8002-72-0. As a complex essential oil, it does not have a single IUPAC name or molecular formula. Instead, it comprises a variety of volatile compounds that contribute to its characteristic aroma and flavor. The oil is typically extracted through steam distillation of onion bulbs.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Onion oil is characterized by a pungent, sulfurous aroma with sweet, savory undertones. Its flavor profile is similarly intense, providing a sharp, spicy taste that is reminiscent of fresh onions. The oil is often used as an impact note in flavor formulations, providing authenticity and depth. The sensory intensity of onion oil is high, and it is typically used in small quantities to avoid overpowering other flavor components.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Onion oil is naturally found in the bulbs of the Allium cepa plant. The formation of its characteristic compounds occurs through enzymatic reactions when the onion cells are damaged, releasing alliinase enzymes that convert alliin to allicin and other sulfur-containing compounds. These reactions are crucial for the oil's designation as a "natural flavor" in regulatory contexts.

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

4. Use in Flavors

Onion oil is widely used in savory flavor applications, including soups, sauces, and snack foods. It serves as a key impact note, providing authenticity and depth to onion-flavored products. Typical use levels in food range from 0.5 to 5 ppm, depending on the desired intensity and the complexity of the flavor system. The oil is relatively stable under heat but can be prone to oxidation, necessitating careful formulation and storage.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrances, onion oil is less commonly used due to its intense and specific aroma. However, it can be employed in niche perfumery to create unique, savory accords or to add a touch of realism to certain compositions. Its volatility places it primarily in the top note category, where it can provide an initial burst of aroma before quickly dissipating.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

5a. Key Constituents (Typical)

Onion oil typically contains a variety of sulfur-containing compounds, including dipropyl disulfide, dipropyl trisulfide, and methyl propyl disulfide. These constituents are responsible for the oil's characteristic pungency and flavor. The composition of onion oil can vary significantly based on factors such as the onion variety, growing conditions, and extraction method.

Citation hooks: FlavScents; peer-reviewed literature; authoritative industry references

6. Regulatory Status (Regional Overview)

In the United States, onion oil is generally recognized as safe (GRAS) for use in food by FEMA. In the European Union, it is regulated under Regulation (EC) No 1334/2008 and is assigned an FL number. Post-Brexit, the UK has aligned with EU regulations, though future divergence is possible. In Asia, regulatory acceptance varies, with Japan and China having specific guidelines for natural flavors. 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

Oral exposure to onion oil in flavor applications is considered safe within the typical use levels, with a wide margin of safety. Dermal exposure in fragrance applications is less common but should be approached with caution due to potential irritation or sensitization. Inhalation exposure is minimal due to the oil's low volatility in typical use concentrations. Overall, the risk profiles for food and fragrance applications are similar, with the primary concern being potential skin irritation.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Onion oil is valued for its ability to impart a realistic onion flavor in savory applications. It synergizes well with other savory notes such as garlic and herbs. Formulators should be cautious of its intensity, as overuse can lead to an overpowering aroma. It is often under-used in complex flavor systems where subtlety is required.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on onion oil is well-established, with comprehensive sensory and regulatory information available. However, there are gaps in specific toxicological data, particularly regarding long-term exposure. Industry practices are generally well-documented, though some variability exists due to the natural variability of the oil's composition.

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

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 2026-05-27 09:28:36 GMT (p2)