CYCLOHEXANE

CAS: 110-82-7 SOLVENT OR VEHICLE

Cyclohexane (CAS 110-82-7) is a nonpolar cyclic hydrocarbon used primarily as a solvent or vehicle. It appears on the US FDA food contact substance list as an indirect additive under specified conditions of use.

What It Is

Cyclohexane is a cyclic aliphatic hydrocarbon identified by the Chemical Abstracts Service with CAS number 110-82-7. It is a clear, colorless, flammable liquid that functions as a nonpolar solvent or vehicle in industrial and laboratory contexts rather than a traditional nutritive food ingredient. It is recognized under regulatory inventories for use in food contact materials, indicating that it may serve technical purposes associated with packaging and processing equipment rather than being directly added to foods themselves. Cyclohexane has synonyms including hexahydrobenzene, hexamethylene, and hexanaphthene that reflect its chemical structure as a saturated six-carbon ring compound derived from petroleum fractions. The molecular makeup of cyclohexane consists solely of carbon and hydrogen atoms forming a six-membered ring structure, which confers nonpolarity and influences its behavior as a solvent for oils, fats, waxes, and other nonpolar constituents. While common laboratory sources list a variety of technical applications, regulatory inventories such as those maintained by the US Food and Drug Administration reference cyclohexane in indirect food additive regulations, which signals that its permitted use is tied to contact with food through packaging or processing rather than as a direct food constituent. Clarifying this role helps distinguish cyclohexane from additives intentionally used to impact food quality or nutrition. Because it is a solvent with specialized industrial applications, cyclohexane is not assigned a typical food additive identification such as an INS number in the Codex Alimentarius, nor is it described in Codex specifications with a numeric acceptable daily intake. Instead, regulatory inventories reference cyclohexane in the context of food contact substance listings, where conditions of safe use are tied to migration limitations and good manufacturing practices.

How It Is Made

Cyclohexane is produced through industrial chemical processes involving the hydrogenation of benzene or the refinement of petroleum fractions containing cyclic hydrocarbons. Typical industrial routes include passing benzene over a nickel catalyst under conditions that promote saturation of the aromatic ring, yielding cyclohexane as a major product. Another production pathway involves hydrocracking of larger hydrocarbon fractions where longer chain cycloalkanes break down under heat and pressure to yield cyclohexane and other components. The resulting product is distilled and purified to meet technical solvent specifications for industrial, analytical, or laboratory uses. Purity standards depend on application but often exceed 99% for analytical solvent grades, with tight limits on moisture and volatile impurities. Because cyclohexane is produced from petrochemical sources, its manufacture is tied to petroleum feedstocks and refinery operations. Cyclohexane’s manufacture does not typically involve food-grade manufacturing processes unless it is specifically processed and certified for analytical laboratories or for food contact material testing, where additional controls on impurities are required. In food contact applications, cyclohexane’s presence reflects regulatory listing rather than direct formulation into food products; purity and production details are important for ensuring that any migration into food from packaging or processing equipment remains within allowable limits defined by regulatory authorities.

Why It Is Used In Food

Cyclohexane itself is not used in foods for flavor, nutrition, or preservation. Its inclusion in regulatory contexts relates to its function as a solvent or vehicle in the manufacturing and processing of food contact materials. As a nonpolar solvent, cyclohexane can dissolve oils, waxes, and other nonpolar substances, making it useful in extracting or applying coatings and adhesives used in food packaging structures. Food contact material regulations often list substances like cyclohexane under conditions of good manufacturing practice, which means that its use must be controlled so that any migration into food is negligible and technically justified. Cyclohexane’s role as a solvent contributes to the production of adhesives, coatings, and other components that must adhere to packaging substrates or serve as carriers for other technically functional substances. Importantly, cyclohexane’s listing within indirect food additive regulations is not an endorsement of its purposeful addition to food products but rather an acknowledgment that it may be used in associated processes. The functional reason for its inclusion is technical handling, extraction, or application of nonpolar components during the fabrication of materials that come into contact with food. In summary, cyclohexane’s use in food-related applications is tied to indirect contact through processing equipment or packaging materials where its solvent properties support manufacturing operations under conditions of good manufacturing practice.

Adi Example Calculation

Because no numeric acceptable daily intake (ADI) has been allocated for cyclohexane by authoritative food additive evaluators, it is not appropriate to provide a numerical example calculation for ADI-based intake. The absence of a defined ADI reflects the fact that cyclohexane’s regulatory status pertains to indirect food contact uses where dietary exposure is expected to be negligible under conditions of good manufacturing practice rather than direct addition to food products. In contrast, illustrative ADI calculations are typically used for substances with established numeric ADIs, where a hypothetical body weight (for example, 60 kilograms) would be multiplied by the ADI value to estimate an allowable daily intake. Because such a numeric value does not exist for cyclohexane, no similar example is provided here.

Safety And Health Research

Safety evaluations for cyclohexane have focused on its properties as a solvent and potential for exposure through inhalation, dermal contact, or indirect migration from food contact materials. Toxicological data from industrial chemical safety documents indicate cyclohexane can produce acute effects such as irritation to the eyes and respiratory tract at high concentrations and may cause central nervous system effects like dizziness at levels considerably above typical environmental exposures. These hazard profiles inform occupational safety guidelines and handling precautions rather than direct dietary risk assessments. Regulatory assessments by bodies such as the Joint FAO/WHO Expert Committee on Food Additives have noted that cyclohexane functions as an extraction solvent without allocating a numeric acceptable daily intake, suggesting that exposure through approved indirect food contact uses under conditions of good manufacturing practice is not anticipated to result in significant dietary intake. Historical evaluations did not prepare a full toxicological monograph, and no numeric ADI was established, reflecting the context of its use and the nature of exposure in food contact scenarios. Laboratory and industrial safety data emphasize flammability and potential acute inhalation hazards, leading workplaces to adopt rigorous ventilation, protective equipment, and exposure controls. These considerations underline that safety evaluations focus on understanding hazard potential in occupational or technical contexts rather than direct effects from dietary consumption, consistent with cyclohexane’s regulatory classification as an indirect additive.

Regulatory Status Worldwide

Cyclohexane is referenced in the United States Code of Federal Regulations under sections that pertain to indirect food additives or food contact substances. Specifically, the US Food and Drug Administration’s Inventory of Food Contact Substances includes cyclohexane with connections to regulatory sections 21 CFR 175.105, 176.200, and 178.3620, which govern the safe use of substances in adhesives, coatings, and other food contact articles when used in accordance with good manufacturing practice. These listings indicate that cyclohexane is authorized for certain technical uses where it may contact food surfaces under controlled conditions but is not directly added to food products themselves. The regulatory citations reflect sections where conditions and limitations on use are defined rather than a direct approval as a nutritive additive. On the international stage, the Joint FAO/WHO Expert Committee on Food Additives evaluated cyclohexane and classified it in a functional class of extraction solvents without allocating a numeric acceptable daily intake, indicating that typical dietary exposure considerations were not established in the additive specification context. The absence of an allocated ADI in the JECFA database reflects the historical review’s conclusion that typical exposure through indirect contact was not suited to an ADI framework. This regulatory context contrasts with substances that have specified limits for direct addition to food. Regulatory authorities outside the United States and the FAO/WHO context may also include cyclohexane on lists of permitted food contact substances, often tied to material safety standards, migration limits, and purity requirements. In all cases, the focus is on ensuring that its presence in food contact applications does not exceed levels that would compromise safety, with conditions for use defined by good manufacturing practice.

Taste And Functional Properties

Cyclohexane has a mild, sweet, petroleum-like odor characteristic of many nonpolar hydrocarbons, but it does not contribute a specific taste profile to foods or beverages because it is not intended as a consumable ingredient. Its functional properties derive from its chemical structure: as a cyclic, saturated hydrocarbon, cyclohexane is nonpolar, immiscible with water, and able to dissolve other nonpolar or hydrophobic substances such as oils, fats, waxes, and resins. These physicochemical characteristics make cyclohexane useful in industrial and analytical contexts, where it acts as a medium for dissolving or carrying nonpolar components during extraction, application, or processing. Its flammability and volatility are important functional considerations in handling rather than food sensory contexts: cyclohexane vapors can evaporate rapidly at room temperature, which influences drying and application processes when used as a solvent in coatings or adhesives used on food contact surfaces. In summary, cyclohexane’s sensory presence is limited to a general nonpolar hydrocarbon odor at technical concentrations and is not associated with taste effects in food because it is not directly added to food products. The functional properties that drive its inclusion in regulatory inventories relate to solvent behavior rather than organoleptic contributions.

Acceptable Daily Intake Explained

An acceptable daily intake (ADI) represents an estimate of the amount of a substance that can be consumed daily over a lifetime without appreciable health risk, typically expressed in milligrams per kilogram of body weight per day. For conventional food additives intentionally added to food for functional purposes, regulatory bodies often assign ADIs based on toxicological data. However, for cyclohexane, no numeric ADI has been allocated by the Joint FAO/WHO Expert Committee on Food Additives, reflecting a lack of dietary exposure considerations typical for substances encountered primarily through indirect contact with food materials rather than intentional inclusion. In indirect food contact contexts, regulators focus on ensuring that substance migration into food remains within levels that are technically justified and below thresholds of concern. Good manufacturing practice criteria define that the use of a substance like cyclohexane should result in only trace amounts contacting food under normal conditions of use. Because the ADI concept is designed for substances directly added to foods, the absence of a numeric ADI for cyclohexane signifies that direct dietary exposure is not a central factor for regulatory evaluations in this case. Consumers and food science professionals should understand that the ADI framework is not universally applied to all substances encountered in the food supply, particularly those associated with food contact materials under controlled conditions. The absence of an established ADI for cyclohexane does not imply a known safety threshold but reflects its regulatory context and low anticipated dietary exposure.

Comparison With Similar Additives

Cyclohexane’s regulatory and functional context can be compared with other substances that serve as indirect food contact solvents or carriers. For example, isooctane is another nonpolar solvent that may appear in analytical applications or material testing rather than as a direct food ingredient, sharing similar physicochemical properties and regulatory attention on indirect uses. Both are nonpolar hydrocarbons with solvent functions but do not have established acceptable daily intakes because typical exposure through indirect contact is minimal. By contrast, direct food additives such as acetic acid (used as a flavoring and preservative) have numeric ADIs and explicit regulatory limits tied to dietary exposure, reflecting intentionally added functional roles in foods rather than incidental contact through packaging. Comparatively, cyclohexane’s status as a solvent used in manufacturing contexts places it in a different regulatory category. Other food contact solvents like ethyl acetate may have similar roles in processing and packaging adhesives or coatings, with regulatory controls to limit migration into food. These comparisons highlight the differences between substances evaluated for direct dietary intake versus those controlled through material standards and good manufacturing practice.

Common Food Applications Narrative

Cyclohexane’s relevance in the context of foods arises primarily from its role as a solvent in the industrial processes that support food packaging and processing equipment. It is listed in regulatory inventories of substances permitted in food contact materials, meaning that under specified conditions of good manufacturing practice, cyclohexane may be used during the manufacture of adhesives, coatings, and components that compose packaging structures such as laminates, containers, and processing surfaces. These materials, once properly manufactured and controlled, can contact foods without contributing significant amounts of the solvent itself to the food. Because cyclohexane is a nonpolar solvent, its industrial use can include extraction steps in essential oil processing or analytical laboratory procedures tied to food ingredient testing, where its ability to dissolve hydrophobic substances supports separation and measurement techniques. Cyclohexane’s use in analytical chemistry, such as chromatography, may help laboratories identify or quantify nonpolar contaminants or constituents in food products, although this is a laboratory application rather than a direct food usage. In packaging contexts, the presence of cyclohexane in adhesives or coatings must be controlled so that migration into food under conditions of use remains within negligible levels as determined by regulatory frameworks. Food processors and packaging manufacturers rely on solvent lists and food contact regulations to ensure that technical solvents like cyclohexane are used appropriately and that finished materials are safe for their intended applications. This indirect association with food contact materials highlights the importance of regulatory compliance rather than direct addition to food formulations.

Safety & Regulations

FDA

  • Notes: Cyclohexane is listed in FDA indirect additive food contact sections but direct approval as a food additive was not established with numeric conditions of use.

EFSA

  • Notes: No EFSA specific food additive evaluation with numeric ADI found.

JECFA

  • Notes: JECFA did not allocate a numeric ADI; evaluation recorded in 1979 without numeric ADI allocation.

Sources

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