FlavScents AInsights Entry: Butyl Lithium (CAS: 109-72-8)

1. Identity & Chemical Information

• Common Name(s): Butyl lithium
• IUPAC Name: Butyllithium
• CAS Number: 109-72-8
• FEMA Number: Not applicable
• Other Identifiers: Not applicable
• Molecular Formula: C4H9Li
• Molecular Weight: 64.06 g/mol
• Functional Groups and Structure–Odor Relevance: Butyl lithium is an organolithium reagent with a simple alkyl chain attached to a lithium atom. It is primarily used in synthetic chemistry and does not have a direct odor relevance in flavor or fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Butyl lithium is not typically associated with a sensory profile relevant to flavors or fragrances. It is a highly reactive compound used in chemical synthesis rather than as a sensory agent. Therefore, it does not have established odor or flavor descriptors, nor does it play a role in sensory applications.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Butyl lithium does not occur naturally. It is synthesized through the reaction of butyl chloride with lithium metal. This compound is not relevant to "natural flavor" or "natural fragrance" designations due to its synthetic origin and lack of occurrence in nature.

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

4. Use in Flavors

Butyl lithium is not used in flavor applications. Its primary role is as a reagent in organic synthesis, particularly in the formation of carbon-carbon bonds. It does not contribute to flavor systems and is not used at any ppm levels in food or beverages.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

Similarly, butyl lithium is not used in fragrance applications. Its chemical reactivity makes it unsuitable for direct use in fragrance formulations. It does not belong to any fragrance families and does not contribute to fragrance profiles.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States (FDA / FEMA GRAS): Butyl lithium is not listed as GRAS for flavor or fragrance use.
• European Union (Reg. (EC) No 1334/2008): Not applicable for flavor or fragrance use.
• United Kingdom: No specific post-Brexit regulations for flavor or fragrance use.
• Asia (Japan, China, ASEAN): No known approvals for flavor or fragrance use.
• Latin America (Brazil, MERCOSUR): No known approvals for flavor or fragrance use.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: Not applicable as butyl lithium is not used in flavors.
• Dermal Exposure: Not applicable as butyl lithium is not used in fragrances.
• Inhalation Exposure: Butyl lithium is highly reactive and can pose significant safety risks if inhaled. It is primarily handled in controlled laboratory environments with appropriate safety measures.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Butyl lithium is valuable in synthetic chemistry for its role in forming carbon-carbon bonds. It is not used in flavor or fragrance formulations due to its reactivity and lack of sensory properties. Formulators in the chemical industry should handle it with care, ensuring proper safety protocols are in place.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on butyl lithium is well-established in the context of its chemical reactivity and use in synthesis. There are no industry-typical practices for its use in flavors or fragrances due to its unsuitability for these applications.

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 (not applicable for butyl lithium)
• Toxicology section covers oral, dermal, inhalation
• Regulatory section mentions US, EU, UK, Asia, Latin America
• If complex natural material: includes section 5a (not applicable for butyl lithium)

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 2026-04-28 18:46:09 GMT (p2)