SODIUM MONO- AND DIMETHYL NAPHTHALENE SULFONATES

CAS: 977052-10-0 ANTICAKING AGENT OR FREE-FLOW AGENT

Sodium mono- and dimethyl naphthalene sulfonates is a technical anticaking agent or free-flow agent regulated for specific food applications under U.S. FDA food additive regulations.

What It Is

Sodium mono- and dimethyl naphthalene sulfonates is a synthetic food additive that functions primarily as an anticaking agent or free-flow agent in certain food processing contexts. It is identified by the Chemical Abstracts Service (CAS) registry number 977052-10-0 and has specific other names including “Sodium methyl- and dimethylnaphthalenesulfonate" and “Sodium mono- and dimethyl naphthalene sulfonate”. These synonyms are recognized in regulatory listings and technical inventories. The additive is included in certain regulatory references, specifically 21 CFR 172.824 and 21 CFR 173.315, which indicates its permitted use under defined conditions and limitations within the United States. As an anticaking or free-flow agent, its role is to help prevent clumping and improve the flow characteristics of powdered or granular ingredients during manufacturing and handling. In regulatory inventories, such as the U.S. Food and Drug Administration’s Substances Added to Food (formerly EAFUS), this chemical is described with its technical effect and associated regulatory citations. This listing confirms that the compound is recognized within the FDA’s framework for food additive usage, albeit under conditional use authorizations. It does not provide a universally broad allowance for all food products but specifies the food categories and processing circumstances where it may be used. Because of this regulatory framing, the compound is understood as a specialized additive rather than a common pantry ingredient. Its presence in food is strictly governed by usage conditions that aim to ensure that it performs its technological role without compromising safety and labeling requirements. The structural identity of sodium mono- and dimethyl naphthalene sulfonates relates to the sulfonate derivatives of naphthalene that have been methylated at one or two positions and neutralized as sodium salts. This structural characteristic contributes to its physicochemical behavior in food systems, such as solubility and interaction with other ingredients. Its designation as a free-flow or anticaking agent reflects this molecular behavior in managing moisture interactions and particle adhesion under defined conditions of use.

How It Is Made

The manufacturing process for sodium mono- and dimethyl naphthalene sulfonates typically involves chemical sulfonation of naphthalene derivatives followed by neutralization with a sodium base to form sulfonate salts. Although specific industrial protocols are proprietary and vary by producer, the general approach in producing sulfonate-type additives begins with naphthalene or methyl-substituted naphthalenes as the core aromatic substrate. In a controlled reactor environment, sulfuric acid or a similar sulfonating reagent is introduced to the aromatic substrate, allowing the formation of sulfonic acid groups at specific positions on the naphthalene ring. The position and degree of methyl substitution influence the distribution of product isomers that result from the sulfonation reaction. After sulfonation, the intermediate sulfonic acids are neutralized with a sodium hydroxide solution, converting them into their sodium salt forms, which are the desired functional products for food additive use. The neutralization step is critical for controlling pH and ensuring that the final product is in the stable sodium sulfonate form. Upon completion of the chemical reaction, the mixture is typically filtered, washed, and dried to remove residual reagents and byproducts. Manufacturers may then mill and sieve the dried salt to achieve consistent particulate size, which is important for reliable performance as an anticaking or free-flow agent. Quality control measures during production include testing for purity, moisture content, particle size distribution, and the absence of undesirable impurities. Food-grade specifications often require that heavy metals and unreacted aromatic compounds remain below defined limits, which are part of additive specifications used by regulatory and standards bodies. While the additive does not have a widely published specification monograph within international code authorities, its production is reviewed in contexts that ensure it meets technological and safety criteria for the permitted uses listed in regulatory texts. Manufacturers supply certificates of analysis and safety data sheets that reflect compliance with processing and quality standards.

Why It Is Used In Food

Sodium mono- and dimethyl naphthalene sulfonates is used in food mainly for its physicochemical function of controlling particle behavior in dry and semi-dry ingredient systems. It is particularly effective in preventing the formation of lumps or clumps that can arise due to moisture absorption or electrostatic interactions between particles. In food manufacturing, free-flow and anticaking agents are commonly added to powders, granules, and other particulate products to ensure they remain pourable, stable during storage, and easier to handle during processing and packaging. Without an effective anticaking agent, many powdered ingredients can aggregate, leading to inconsistent dosing, processing challenges, and reduced product quality. Within the regulatory framework that permits its use, this additive is authorized under specific conditions where its technological effect is demonstrated and controlled. For example, under 21 CFR 172.824, it may be used in the crystallization of sodium carbonate at defined concentrations to manage the physical characteristics of sodium carbonate products. In this application, the compound helps ensure that the crystals remain discrete rather than forming large aggregates, which can impact processing performance. Similarly, as an anticaking agent in sodium nitrite formulations, the sulfonate additive helps maintain flowability and consistent functional performance in applications where nitrite is used for curing. These uses underscore the importance of free-flow and anticaking agents in maintaining product quality and process efficiency. Such agents do not contribute directly to flavor, nutrition, or other sensory attributes but play a crucial role in meeting industrial and technical requirements. Their inclusion is often invisible to consumers but essential to ensuring that food ingredients perform as intended from manufacturing through to end user application.

Adi Example Calculation

Because no authoritative numeric ADI value for sodium mono- and dimethyl naphthalene sulfonates could be confidently identified from available regulatory evaluations, a numerical example calculation cannot be provided for this additive. In general, if an ADI were available, an illustrative calculation would multiply the ADI by a hypothetical body weight to estimate a theoretical maximum amount of additive exposure considered without appreciable harm. For instance, if a hypothetical ADI of X mg per kilogram body weight were established, a person weighing 70 kg would have a calculated intake limit of 70 times that ADI. However, without a verified numeric ADI from an authoritative source, such an example would be speculative rather than evidence-based. Regulatory documents emphasize controlled usage conditions and labeling requirements rather than general population intake thresholds when detailed ADIs are not publicly specified.

Safety And Health Research

Regulatory evaluations of food additives like sodium mono- and dimethyl naphthalene sulfonates focus on the compound’s safety profile in the context of human exposure from food. Safety assessment frameworks consider a range of toxicological endpoints, such as acute toxicity, chronic toxicity, carcinogenic potential, and reproductive effects, to determine whether a substance can be safely used within the established conditions of use in food processing. For this specific additive, publicly available safety research summaries from major international bodies such as JECFA were not identified in the evidence reviewed. This means that detailed toxicology reports, including standard acceptable daily intake (ADI) values or food additive series evaluations, could not be confirmed from authoritative sources at the time of writing. As a result, definitive statements about individual health effects cannot be made without access to the original scientific data and evaluations. In the context of U.S. regulation, the inclusion of the compound in the Code of Federal Regulations indicates that the Food and Drug Administration has reviewed data demonstrating that, under specified conditions and concentrations, its use does not pose an unreasonable risk of harm when applied in compliance with regulatory requirements. However, beyond the conditions of use and labeling mandates in 21 CFR 172.824 and 21 CFR 173.315, the broader toxicological footprint of this additive has not been the subject of widely disseminated public safety evaluations akin to those available for more common food additives. Researchers and regulatory scientists generally emphasize that safety assessments are iterative and based on the best available evidence. For this reason, the absence of a publicly available detailed evaluation should not be interpreted as a finding of risk or safety; it reflects the current state of publicly accessible documentation. Continued monitoring of regulatory databases and scientific literature is necessary to determine whether new studies or assessments emerge that provide deeper insights into the safety profile of this compound in food applications.

Regulatory Status Worldwide

In the United States, sodium mono- and dimethyl naphthalene sulfonates is listed within the Food and Drug Administration’s regulations as a food additive permitted for direct addition to food for human consumption under specific conditions. Under 21 CFR 172.824, this compound may be used in the crystallization of sodium carbonate and as an anticaking agent in sodium nitrite products, with labeling provisions required when used in these contexts. Additionally, 21 CFR 173.315 describes its use in chemicals applied for washing or assisting in the peeling of fruits and vegetables. These regulations define both how and where the additive may be applied, and they require adherence to labeling and usage limits set forth in the Code of Federal Regulations. (联邦公报) Outside the United States, regulatory recognition of this specific additive under identical or similar allowances is not broadly documented in the major international additive numbering systems such as the International Numbering System (INS) or the European Union’s E-number system. No E-number designation is widely documented for this compound, and there is limited publicly available information on approvals in the European Union or other regions. As such, its acceptance and permitted uses may differ considerably in jurisdictions outside of U.S. regulatory frameworks. At the international level, organizations such as the Joint FAO/WHO Expert Committee on Food Additives (JECFA) maintain databases and publications that summarize evaluations and specifications for many food additives. While JECFA’s searchable database includes entries for a wide range of food additives, definitive assessment data, acceptable daily intake values, and other specific safety parameters for this compound were not readily identified in available global summaries at the time of writing. This absence in public summaries means that explicit global safety thresholds or evaluations by JECFA are not currently represented in authoritative documents that can be confirmed with deep-link evidence.

Taste And Functional Properties

Sodium mono- and dimethyl naphthalene sulfonates, as a sodium sulfonate derivative, is not added to food for sensory impact such as taste or aroma. Its functional behavior is grounded in physical chemistry rather than flavor modulation. Typically, compounds in this class exhibit neutral taste activity at the low levels permitted in food because they are used in quantities that are technologically necessary rather than organoleptically relevant. In other words, the concentrations in which they are applied do not meaningfully affect the taste profile of the final food product, and sensory attributes are typically unaffected. From a functional perspective, this additive interacts with moisture and adjacent particles in a way that hinders particle-particle adhesion. It serves as a physical agent at interfaces, helping maintain discrete particles in powders, granules, and crystalline preparations. Its solubility in water and other polar media allows it to distribute uniformly in systems where moisture or liquid is present. In terms of stability, sodium sulfonate derivatives generally maintain their integrity under normal storage conditions and do not readily degrade at ambient temperatures. Their stability across a range of pH conditions can also support their utility in diverse food processing environments. Because the compound is not intended to react with other food components in a way that changes flavor, texture, or nutritional properties, it is classified primarily as a processing aid. This distinction means that its impact is technological and functional rather than sensory. As is standard for anticaking agents, it does not impart noticeable color, odor, or taste when applied within the regulated concentration limits. The functional properties that matter most are its ability to promote free flow and reduce caking over time and under conditions of varying humidity.

Acceptable Daily Intake Explained

An acceptable daily intake (ADI) is a health-based reference value used by regulatory scientists to estimate the amount of a food additive that can be ingested daily over a lifetime without appreciable health risk. ADIs are typically derived from toxicological studies in animals or humans and include safety factors to account for uncertainties in extrapolating data. For sodium mono- and dimethyl naphthalene sulfonates, a specific numeric ADI value from authoritative global risk assessments (such as JECFA) could not be located in the available public regulatory records at this time. Therefore, no numeric ADI has been assigned in this article due to the lack of verifiable evidence from deep-link regulatory sources. It is important to understand that the absence of an assigned ADI in this narrative does not imply a safety concern; rather, it reflects the current accessibility of documented evaluations. In regulatory practice, when authorities establish permitted uses for food additives, they consider the available safety data and impose conditions of use that are designed to ensure that consumer exposure remains within safe limits. The ADI concept helps regulatory bodies set those conditions and interpret toxicological data, but not all permitted additives have widely published ADI values in public-facing summaries. In such cases, regulatory acceptance under defined conditions of use reflects an implicit determination that the likelihood of harm at authorized use levels is low, based on the scientific evidence provided to regulators.

Comparison With Similar Additives

Sodium mono- and dimethyl naphthalene sulfonates is one of a class of anticaking and free-flow agents used in food processing, but there are several other additives with similar functions that are more widely recognized. For example, calcium silicate and silicon dioxide are frequently used to improve the flow properties of powdered food ingredients. Like sodium sulfonate derivatives, these mineral-based agents work by creating physical separation between particles, reducing moisture-induced clumping and maintaining pourability. Their widespread documentation in safety assessments makes them common examples in ingredient reference contexts. Another similar additive class includes magnesium stearate and stearic acid salts, which are used in various food and supplement applications to promote release from manufacturing equipment and inhibit caking. These compounds, like sulfonate-based anticaking agents, function through physical mechanisms rather than flavor modulation. A third example is tricalcium phosphate, which serves as a free-flow agent in powdered products such as table salt and spice blends. All these agents share a common functional theme: they facilitate handling and processing efficiency by altering particle interactions. However, each compound has its own regulatory and safety profile, and the availability of comprehensive safety evaluations can differ widely. The comparison highlights that while many anticaking agents serve analogous technological purposes, their regulatory treatment and the depth of publicly accessible safety data can vary significantly.

Common Food Applications Narrative

In practical food processing contexts, free-flow and anticaking agents like sodium mono- and dimethyl naphthalene sulfonates play a supporting yet important role in a variety of powdered and granular ingredients. Manufacturers often rely on such agents to ensure that ingredients such as salt blends, seasoning mixes, and curing salts remain easy to dispense, mix, and store. When powdered ingredients are prone to absorbing moisture from the environment, there is a risk that they will clump together, leading to blockages in dosing equipment and inconsistency in ingredient distribution. Inclusion of a certified anticaking additive helps maintain the discrete flow of particles, which supports efficiency and consistency for industrial processes. For example, in the production of dry curing mixtures used in the preparation of some preserved meats or fish, anticaking agents are often incorporated to keep sodium nitrite and associated components free-flowing. The presence of an effective anticaking agent can reduce processing downtime by preventing aggregates that would otherwise require manual intervention. Similarly, dry seasoning blends and powdered flavor systems that are packaged for consumer use benefit from enhanced shelf stability when anticaking agents are included, as they help maintain a uniform texture and ease of use throughout the product’s shelf life. Another practical application is seen in industrial-scale production of certain mineral salts, where the additive assists in maintaining controlled crystal growth and separation during crystallization steps, which can affect downstream handling. Across these varied scenarios, the use of free-flow agents reflects the constant need in food manufacturing to balance ingredient functionality with handling efficiency. While consumers may never see or taste these additives in finished products, they contribute to consistent manufacturing outcomes and reliable ingredient performance in formulated food systems.

Safety & Regulations

FDA

  • Approved: True
  • Regulation: 21 CFR 172.824 and 21 CFR 173.315

EFSA

  • Notes: EFSA regulatory status not identified in available authoritative sources

JECFA

  • Notes: A JECFA evaluation or numeric ADI was not confirmed in available public databases

Sources

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