1,3-BUTYLENE GLYCOL

CAS: 107-88-0 FLAVORING AGENT OR ADJUVANT, SOLVENT OR VEHICLE

1,3-Butylene glycol is a diol used in food and industrial applications as a solvent, carrier, and formulation aid. It has been evaluated by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) with an established ADI range.

What It Is

1,3-Butylene glycol is a small organic compound classified chemically as a diol and technically as a solvent, flavoring agent or flavor adjuvant, and processing aid in food and industrial formulations. Identified by the Chemical Abstracts Service (CAS) number 107-88-0, it appears as a colorless liquid at typical conditions with two alcohol functional groups that confer good water solubility and low volatility. Because of this chemical structure and its functional profile, it is applied in diverse sectors including food processing, cosmetics, and material sciences as a carrier or vehicle for other additives and ingredients. Within food applications, 1,3-Butylene glycol serves primarily to carry volatile flavor components and improve blending of flavor materials into food matrices. The compound is also incorporated into formulations as a processing aid, helping to achieve uniform distribution of functional ingredients. Although it does not contribute significant taste by itself at low levels, it supports the sensory performance of other compounds by improving their dispersion and retention in food products. From a regulatory standpoint, 1,3-Butylene glycol is recognized under specific provisions that authorize its use in food manufacture under defined conditions and specifications. The compound is evaluated internationally by expert panels such as JECFA, which has reviewed its safety profile and established acceptable intake recommendations to inform regulatory frameworks globally.

How It Is Made

The synthesis of 1,3-Butylene glycol typically involves the aldol condensation of acetaldehyde followed by catalytic hydrogenation. In this process, acetaldehyde molecules undergo condensation to form 3-hydroxybutanal, which is then hydrogenated in the presence of a catalyst to produce the diol structure characteristic of 1,3-Butylene glycol. This route yields a racemic mixture of configurations in many commercial preparations and is the basis for the preparation specified in regulatory texts for food-grade material. In the United States, for example, this method of preparation is explicitly mentioned within the regulatory standard for food additive identity and specification. Once synthesized, the raw product is purified and tested to meet defined identity and purity specifications, often aligned with standards such as those in the Food Chemicals Codex. The purification process focuses on removing residual reactants and byproducts to ensure the substance meets safety and quality criteria suitable for its intended applications. The resulting compound is generally characterized by its clear appearance, low odor, and ability to dissolve in water and many organic solvents. In industrial and commercial settings, manufacturers may apply additional refinement steps such as distillation, filtration, or decolorization to achieve the high purity required for food, cosmetic, or pharmaceutical use. Regardless of the final application, adherence to relevant specifications ensures consistency and safety of the finished ingredient.

Why It Is Used In Food

1,3-Butylene glycol is used in food primarily for its functional properties as a solvent, carrier, and processing aid. Its chemical structure enables it to solubilize a wide range of organic flavor compounds, helping incorporate these components into food matrices more effectively than water alone. This functional versatility makes it useful in flavor formulations where uniform distribution and stability of flavor molecules are essential. Beyond flavor delivery, 1,3-Butylene glycol can act as a vehicle for processing aids that support texture or consistency during food manufacture. For example, it may be used in the preparation of casings or coatings where it serves as an inert carrier that does not interfere with the primary functional elements of the food. Although it does not impart a defined taste at typical use levels, its presence can improve the performance of other ingredients by enhancing solubility and reducing crystallization of certain components. Because of these properties, food technologists choose 1,3-Butylene glycol in applications where complex flavor systems or uniform incorporation of minor ingredients are critical. Its compatibility with water and various organic substances further broadens its utility across diverse formulations.

Adi Example Calculation

To illustrate how an acceptable daily intake (ADI) might be applied in a hypothetical context, consider a hypothetical adult with a body weight of 70 kilograms. Using an ADI of up to 4 mg per kilogram of body weight per day, the total allowable intake for this hypothetical individual would be calculated by multiplying 4 mg by 70 kg, resulting in a theoretical upper reference intake of 280 mg per day. This example is illustrative and is not intended as personal guidance. It reflects how regulatory organizations use ADIs to contextualize safety margins and assess whether typical exposure from food use is consistent with levels considered safe over a lifetime. Actual intake in real-world scenarios is often considerably lower due to limited use levels and varied consumption patterns of products containing the additive.

Safety And Health Research

Safety assessments of 1,3-Butylene glycol consider its toxicity profile relative to expected human exposure levels from food. Toxicological data reviewed by expert committees such as JECFA include evaluations of acute toxicity and other endpoints to determine a range of intake that is not expected to pose health risks in the general population. Based on these assessments, JECFA established an acceptable daily intake (ADI) range of 0-4 mg/kg body weight per day, incorporating conservative safety factors to address uncertainties in the data. (JECFA TRS 648-JECFA 23/15) (世界卫生组织应用程序) Key aspects of safety research typically involve examining effects in laboratory models across multiple exposure levels to identify thresholds for adverse outcomes. Toxicological endpoints that inform additive safety include assessments of systemic toxicity, potential for mutagenicity, and organ-specific effects, among others. Expert panels weigh these findings alongside estimated dietary exposures to determine whether a substance can be used safely under specified conditions. While the ADI provides a benchmark for regulatory risk assessment, actual exposure from food use is generally anticipated to be well below this range due to limited application levels and functional use patterns. Continued review and monitoring by regulatory agencies ensure that safety evaluations remain aligned with emerging data and usage trends.

Regulatory Status Worldwide

In the United States, 1,3-Butylene glycol is specifically listed in Title 21 of the Code of Federal Regulations at section 172.712 as a permitted food additive when used in accordance with prescribed conditions, including preparation method and identity specifications. This regulatory text indicates that the substance may be safely used in food and refers to established quality criteria such as those in the Food Chemicals Codex for identity and purity. It is also permitted as a formulation and processing aid in the manufacture of sausage casings under the defined regulatory framework. (21 CFR 172.712) At the international level, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) has evaluated 1,3-Butylene glycol and assigned it a functional class as a carrier or solvent. JECFA’s evaluation includes an acceptable daily intake (ADI) range of 0-4 mg/kg body weight per day, reflecting the committee’s assessment of toxicological data available at the time of the review. (JECFA TRS 648-JECFA 23/15) (世界卫生组织应用程序) Regulatory positions in other jurisdictions such as the European Union or Codex Alimentarius may reference similar evaluations and specifications, aligning with JECFA guidelines for food additive safety. However, specific legislative listings and conditions can vary by region, and formulators often consult local food safety authorities for detailed compliance requirements.

Taste And Functional Properties

In sensory terms, 1,3-Butylene glycol itself has minimal taste at low exposure levels, which allows it to function as a neutral carrier for flavor compounds without contributing a strong sensory note. At higher concentrations outside of typical food use, it may exhibit a slight bitterness or sweetness, but this is not a defining characteristic for its approved applications. Its primary sensory role is to support the delivery and perception of other flavoring ingredients by aiding their dissolution and dispersion. Functionally, 1,3-Butylene glycol is miscible with water and many organic solvents, making it an effective vehicle for both hydrophilic and hydrophobic flavor constituents. It also has a relatively low volatility compared to simpler alcohols, which helps retain volatile flavor compounds during processing and storage. These properties contribute to improved uniformity and stability in complex flavor systems. From a physicochemical perspective, its diol structure confers moderate polarity, enabling interactions with a range of molecular types. This polarity, combined with its solubilizing capacity, makes it valuable in blends where multiple classes of flavor molecules must coexist without phase separation. Additionally, its stability under typical food processing temperatures further supports its utility in diverse applications.

Acceptable Daily Intake Explained

An acceptable daily intake (ADI) represents a level of daily intake over a lifetime that, based on current evidence, is considered unlikely to pose a health risk to humans. For 1,3-Butylene glycol, JECFA has established an ADI range of 0-4 mg per kilogram of body weight per day, reflecting the range of intake that expert reviewers consider safe when used in food within the parameters of good manufacturing practice. (JECFA TRS 648-JECFA 23/15) (世界卫生组织应用程序) It is important to understand that ADI values are not recommended dietary targets but rather safety reference points. They are derived from toxicological studies in which the highest exposure level that does not produce adverse effects is identified, and then safety factors are applied to account for variability between individuals and uncertainties in the data. Regulatory authorities use ADI values to inform risk assessments and to set conditions for allowable use in food products.

Comparison With Similar Additives

1,3-Butylene glycol shares functional characteristics with other diol compounds used in food technology, such as propylene glycol and glycerol. Like 1,3-Butylene glycol, propylene glycol is widely used as a solvent and carrier for flavors and other additives, and both compounds have relatively low volatility and high solubility in water. However, regulatory acceptance and specific conditions of use differ between them, with propylene glycol having broader listings in many jurisdictions. Glycerol, a triol with three alcohol groups, also serves as a solvent and humectant in food formulations, offering higher polarity and viscosity relative to 1,3-Butylene glycol. The additional hydroxyl group in glycerol influences its functional behavior, making it more effective as a humectant and texture modifier, whereas 1,3-Butylene glycol is often selected for solvent and carrier functions. Compared to simple alcohols such as ethanol, these diols provide greater solvent capacity for certain classes of flavor compounds while presenting lower volatility, enhancing their role in stabilizing complex flavor systems. The choice between these related additives depends on the specific functional needs of the formulation and the regulatory context in which they are used.

Common Food Applications Narrative

In food processing, 1,3-Butylene glycol is incorporated in formulations where the uniform delivery and stability of flavor compounds are important. It is used in flavor systems for beverages, sauces, dressings, and other prepared foods to help disperse volatile aromatic components that define the desired sensory character. Because it acts as a solvent and carrier, it is particularly useful in complex systems where multiple flavor molecules must remain stable and evenly distributed throughout the product. Food manufacturers also employ 1,3-Butylene glycol as a processing aid in the production of specialized ingredients such as casings for sausages, where it contributes to achieving the desired physical properties without affecting the food's organoleptic profile. Its role in such applications is not to provide taste but to assist in the functional transformation of raw materials into finished components that meet quality standards. Additionally, because of its ability to blend with water and organic flavoring agents, this compound supports the creation of consistent flavor bases used by culinary developers and food formulators. Its inclusion in these applications reflects a balance between functional performance and regulatory acceptance, enabling product developers to meet both technological needs and compliance requirements.

Safety & Regulations

FDA

  • Approved: True
  • Regulation: 21 CFR 172.712

EFSA

  • Notes: EFSA evaluation for this specific additive not located in authoritative sources

JECFA

  • Year: 1979
  • Adi Display: 0-4 mg/kg bw
  • Adi Mg Per Kg: 4

Sources

Comments

No comments yet. Be the first to share!