1,6-HEXANEDITHIOL

CAS: 1191-43-1 FLAVOR ENHANCER, FLAVORING AGENT OR ADJUVANT, SOLVENT OR VEHICLE

1,6-Hexanedithiol is a synthetic sulfur containing organic compound used primarily as a flavoring agent and solvent with a characteristic meaty and burnt aroma profile, recognized under FEMA number 3495 and evaluated by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) with no safety concern identified at current levels of intake when used as a flavoring agent.

What It Is

1,6-Hexanedithiol is an organosulfur compound characterized by a six carbon aliphatic chain terminating in thiol (-SH) groups on each end of the molecule. This chemical, which carries the CAS number 1191-43-1, is listed under the FEMA flavor library with FEMA number 3495 and has a JECFA number of 540, indicating its inclusion in evaluations by the Joint FAO/WHO Expert Committee on Food Additives for safety when used in food flavoring applications. Its structure features two thiol groups, which impart functional behavior in aroma and flavor systems as well as influence solvent characteristics when included in formulation matrices. In the context of food technology, 1,6-Hexanedithiol falls into categories defined by its function as a flavor enhancer, flavoring agent or adjuvant, and in some applications as a solvent or vehicle ingredient in complex flavor blends. The compound is typically a clear to slightly yellow liquid under standard conditions and contributes distinctive savory and burnt notes when used appropriately in food flavorings. Scientific and industrial databases describe its odor and flavor qualities and document its technical use in savory flavors, reflecting its functional niche in flavor chemistry and formulation design. Such attributes make 1,6-Hexanedithiol relevant to food scientists developing complex savory profiles, especially in meat, poultry, and soup type flavor applications. Given its sulfurous functional groups and unique sensory profile, it is often managed at very low usage levels in food products to achieve the desired effect without overpowering the overall flavor balance. Sources describing its properties emphasize its use in flavor systems at concentrations that are effective yet within safety guidelines established by expert panels and technical literature.

How It Is Made

The manufacture of 1,6-Hexanedithiol generally begins with commercially available hydrocarbon precursors, such as 1,6-dibromohexane or similar alkyl dihalides. Through established organic synthesis pathways, the dihalide precursor undergoes thiolation, often using reagents that introduce the thiol functional groups on each end of the carbon chain. This transformation typically involves the reaction of the dihalide with a sulfur donor under controlled pH and temperature conditions to form the dithiol structure. Industrial organic chemistry literature outlines such multistep syntheses that are designed to yield high purity bifunctional thiols while minimizing byproducts and ensuring manageable reaction profiles. Following synthesis, the material is purified using standard techniques such as distillation or solvent extraction to remove impurities and meet specifications suitable for its intended use, whether that is for flavor chemistry, solvent applications, or research use. Analytical characterization of the resulting product includes verification of the chemical identity through techniques such as gas chromatography or mass spectrometry, and purity assessments via established chemical standards. Suppliers and technical data sources list common physical properties such as melting point, boiling point at reduced pressures, density, refractive index, and vapor pressure, which assist manufacturers and formulators in understanding how the compound will behave in different matrices and processing conditions. Because of its sulfur-containing functional groups and potential for odor activity, manufacturing and handling protocols emphasize closed systems and adequate ventilation to protect worker safety and prevent undue odor release. While detailed proprietary methods are used by specific manufacturers, the broad chemical community recognizes that the underlying synthesis approach is grounded in well-established thiol chemistry and organic reaction mechanisms that favor the formation of terminal dithiols. Manufacturers often adapt these general methods to their specific facilities and regulatory environments, ensuring consistency with quality and safety standards appropriate for flavored ingredient production. Overall, the manufacturing context for 1,6-Hexanedithiol reflects standard industrial approaches to producing functional organosulfur compounds with consistent quality characteristics for use in flavoring insights and other technical applications.

Why It Is Used In Food

1,6-Hexanedithiol is used in food because of its ability to impart distinctive savory, meaty, and burnt aroma characteristics when incorporated into flavor formulations. Flavor chemists value this compound for its capacity to mimic or enhance the complex aroma profiles associated with cooked meats, broths, and roasted products. When the thiol groups interact with other flavor constituents, they can contribute to depth, richness, and the perception of umami-like savory notes that are challenging to achieve using other classes of compounds. In practical terms, it serves as a flavor enhancer or flavoring agent in low concentrations, helping balance and amplify sensory attributes in savory products such as stocks, soups, meat and poultry related seasonings, and other culinary applications where a robust sensory profile is desirable. The technical function of 1,6-Hexanedithiol in food systems includes its role as a delivery vehicle for specific notes in a flavor blend; its solubility profile in oils and alcohols and its moderate volatility support its integration into complex liquid or dry flavor premixes. Because of the potency of the sensory impression it delivers, it is typically used at trace levels in formulations to avoid excessive sulfurous or overpowering sensory effects. Regulatory and expert evaluations, including by technical bodies such as FEMA and the FAO/WHO expert committee, have guided the accepted usage patterns and advised on the concentrations and contexts in which the substance can be incorporated without raising safety concerns. Its inclusion in flavor libraries and formulation references underscores its recognized purpose in enrichening sensory complexity in formulated food products. As with all flavoring agents, its use is guided by sensory performance, formulation goals, and adherence to safety and quality standards appropriate to the food matrix being developed.

Adi Example Calculation

Because a specific numeric Acceptable Daily Intake (ADI) value has not been assigned for 1,6-Hexanedithiol in publicly available expert evaluations, an illustrative calculation using a numeric ADI is not provided here. In general, when a numeric ADI is established for a food additive, a calculation might involve multiplying the ADI (expressed in terms such as milligrams per kilogram of body weight per day) by a hypothetical body weight to estimate how much of the substance could theoretically be consumed daily without exceeding safety guidance. For example, if an expert body were to set an ADI of X mg/kg body weight/day for a flavoring substance, a person weighing Y kilograms would have an illustrative limit of X times Y mg per day, interpreted within the specific context of that substance’s use and exposure patterns. In the absence of a numeric ADI for 1,6-Hexanedithiol, this explanation underscores how ADI based calculations are applied in regulatory science more broadly, without offering specific numerical guidance for this particular compound.

Safety And Health Research

Safety evaluations for 1,6-Hexanedithiol focus on its toxicological profile, potential irritancy, and intake levels relative to expected exposure from its use as a flavoring agent. Regulatory expert panels such as FEMA and JECFA review available data, including results from animal toxicology studies and information on sensory irritation, to inform their assessments. For example, the FEMA flavor library entry documents consideration of irritant properties and other toxicological endpoints derived from standard studies, with guidance that informs recommended maximum usage concentrations in food applications to maintain a margin of safety. Expert evaluations by JECFA have concluded that current levels of intake from its use as a flavoring agent do not present a safety concern, a determination that is reflected in summary reports prepared by the Committee for substances evaluated during its meetings. Such evaluations take into account available toxicology data, exposure estimates, and the functional role of the compound in food formulations to conclude that 1,6-Hexanedithiol can be used within specified technical contexts without undue risk to consumers. Toxicological research typically considers endpoints such as organ system effects, acute and chronic toxicity, and irritation potential, with results informing the overall safety profile used by expert panels to generate their conclusions. The designation of “no safety concern at current levels of intake” by JECFA indicates that, based on the data available at the time of review, the compound’s expected exposure from its intended use falls well below thresholds of concern identified in toxicity studies. This does not imply absence of effect at sufficiently high doses; rather it situates typical dietary exposure well within a range judged acceptable by experts. Ongoing monitoring of new research and data can influence future evaluations, and manufacturers and regulators alike remain attentive to emerging evidence that might alter safety assessments or guidelines. In practice, adherence to recommended usage levels and formulation best practices ensure that the compound’s functional benefits in flavor systems are balanced with consumer safety considerations.

Regulatory Status Worldwide

The regulatory landscape for 1,6-Hexanedithiol reflects its classification and evaluation as a flavoring agent rather than as a general ingredient authorized for unrestricted use. In the United States, it is recognized in the FEMA flavor library with FEMA number 3495, indicating that expert review by the Flavor and Extract Manufacturers Association has assessed its safety and provided guidance on its use as a flavoring substance. Publicly accessible inventories, such as the FDA Substances Added to Food database, reference its FEMA number and technical effect definitions that align with federal regulations for food ingredients, though specific usage levels are advised by expert panels rather than enumerated in a direct section of the Code of Federal Regulations. At the international level, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) has evaluated 1,6-Hexanedithiol in its capacity as a flavoring agent with JECFA number 540, concluding that there is no safety concern at current levels of intake when used for this purpose based on available data at the time of review. This conclusion is reflected in technical monographs and evaluation summaries prepared by the Committee, which serve as reference points for member countries considering national or regional food additive policies. The absence of a specific Authorized Daily Intake (ADI) value in such evaluations is typical for flavoring agents when the expert committee determines that the compound does not present a safety issue at anticipated levels of exposure from its intended use. National agencies and regulatory frameworks often incorporate or reference JECFA and FEMA findings to support their own guidance on flavoring substance use, allowing for consistency across jurisdictions while accounting for differing statutory approaches to food additive authorization. In sum, 1,6-Hexanedithiol’s regulatory status as a flavoring agent is underpinned by expert reviews that identify its role and safety profile within defined usage contexts, rather than broad explicit permissions for unrestricted application across all food categories.

Taste And Functional Properties

1,6-Hexanedithiol has organoleptic properties that are characteristic of sulfur containing compounds, with sensory descriptors including burnt, fatty, and savory meaty notes when perceived at appropriate concentrations in flavor systems. Such descriptors emerge from the interaction of the terminal thiol groups with olfactory receptors, especially in synergy with lipid derived flavor compounds that occur naturally in cooked meats and savory foods. Its inclusion in flavor systems is typically targeted toward enhancing complex aroma profiles where such sulfurous notes contribute positively to the overall flavor impact. From a functional standpoint, 1,6-Hexanedithiol exhibits solubility in organic media and fats rather than in water, aligning with its use in flavor oil systems and lipid-rich food matrices. Its moderate hydrophobic character influences how it partitions in multi-component formulations and supports its performance as a carrier or co-solvent for other sensory active components. The boiling point and vapor pressure characteristics of the compound influence how it volatilizes and contributes to aroma release during consumption, making it suitable for nuanced adjustments to the sensory profile when consumed. Its physical behavior under different pH and temperature conditions is consistent with many small organosulfur compounds, which can be stable under typical processing conditions but require careful handling to maintain consistency in final blends. The thiol functional groups also influence reactivity with other components, which is taken into account by flavor chemists when designing stable, balanced systems that deliver the desired sensory experience without off-notes or instability over the shelf life of the product. Understanding these functional properties is important for formulators seeking to leverage the unique sensory impact of 1,6-Hexanedithiol while maintaining overall product quality and consistency across batches. Due to the strength of its sensory impact, careful calibration of usage levels and blending with complementary compounds is a common practice in flavor design workflows.

Acceptable Daily Intake Explained

An Acceptable Daily Intake (ADI) is a scientific concept used in food additive safety to express the amount of a substance that can be ingested daily over a lifetime without posing significant health risk, based on current evidence and expert judgment. For many flavoring agents, including 1,6-Hexanedithiol, expert bodies such as JECFA sometimes conclude that there is no safety concern at the levels typically consumed in food, in which case a specific numeric ADI may not be allocated. Such a determination reflects the understanding that anticipated exposure from intended uses is far below any levels associated with adverse effects in toxicological studies, and that the compound’s use pattern does not present a meaningful risk to consumers. Explaining this concept helps contextualize why some flavoring agents are described as safe at typical intake levels without assigning a rigid numeric ADI: the safety assessment weighs the evidence on exposure and toxicology together to judge that routine consumption through food does not warrant a conservative numerical limit. It’s important to emphasize that an ADI is not a recommendation to consume a substance, but rather a reference point derived from safety data and expert evaluation. In the case of 1,6-Hexanedithiol, available evaluations conclude that use as a flavoring agent at standard practice levels does not pose a safety concern, and therefore a specific numeric ADI value is not assigned in public evaluation summaries. This reflects a regulatory context where the focus is on maintaining usage within established technical functions and expert recommendations to ensure consumer safety.

Comparison With Similar Additives

1,6-Hexanedithiol can be compared with other sulfur containing flavor compounds that serve similar functions in savory and meat like flavor systems. For instance, ethanethiol derivatives and other low molecular weight thiols are also used in flavor design to contribute sulfurous, roasted, or savory notes in formulations. Compared with simpler thiol compounds, 1,6-Hexanedithiol’s longer carbon chain and terminal thiol groups influence both its volatility and sensory profile, often delivering a more sustained, nuanced meaty impression at concentrations suitable for formulation. By contrast, smaller thiols may be more volatile and perceived as sharper or more pungent, requiring careful balance with other flavor elements. Additionally, organosulfur compounds such as thiazoles and furans are used in savory systems; these heterocyclic sulfur derivatives provide distinct roasted or toasted notes, whereas 1,6-Hexanedithiol’s profile leans toward fatty, meaty aspects. Each class of compounds contributes different sensory dimensions, and formulators often combine multiple ingredients to achieve desired effects. Understanding the comparative sensory characteristics and functional behaviors of these related additives helps flavor scientists select and balance components to achieve target profiles without exceeding safety guidelines or overwhelming the overall aroma and taste experience.

Common Food Applications Narrative

In practical application, 1,6-Hexanedithiol is encountered in a range of savory flavor formulations where a rich, robust sensory profile is desired. It often appears in complex mixes designed to emulate the depth and character of cooked meats, stocks, broths, and roasted products. Flavor professionals might reach for this compound when modeling the intricate interplay of roasted, fatty, and umami-associated notes characteristic of hearty soups, gravies, and dynamic seasoning blends. In such contexts, its capacity to contribute to the meaty dimension of a flavor profile means it can be paired with other sulfur containing compounds, amino acid derived flavor enhancers, and Maillard reaction analogs to deliver a rounded sensory impact that is both recognizable and appealing in finished food products. For manufacturers of culinary bases or soup concentrates, 1,6-Hexanedithiol can serve as one element in a broader palette of aromatic chemicals that together build a convincing impression of slow cooked flavors. Similarly, in snack seasonings, savory sauces, and prepared meal kits, it functions as part of a suite of flavor elements that collectively target consumer expectations for hearty, satisfying taste experiences. The narrative of its application extends into categories where savory notes are central to the consumer appeal, including meat analog products, ready-to-eat meals, and seasoning packets that must deliver potent sensory impressions without reliance on excessive amounts of salt or sugar. In all such uses, the compound is incorporated at regulated, controlled levels, often guided by expert panel assessments and internal quality criteria, to achieve the desired flavor outcome without overwhelming the balance of the formulation. As a trace additive in a spectrum of savory applications, it plays a supporting but meaningful role in shaping the overall sensory identity of many food products designed to meet specific consumer taste preferences.

Safety & Regulations

FDA

  • Notes: FDA references this substance in the EAFUS database, but specific CFR authorization sections are not identified in the d source.

EFSA

  • Notes: EFSA evaluation details for 1,6-Hexanedithiol were not identified in the d sources.

JECFA

  • Notes: JECFA evaluation found no safety concern at current levels of intake but did not assign a specific numeric ADI on the d summary.
  • Adi Display: No specific numeric ADI allocated; expert committee concluded no safety concern at current intake levels

Sources

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