OZONE

CAS: 10028-15-6 ANTIMICROBIAL AGENT

Ozone (CAS 10028-15-6) is a reactive three-oxygen molecule used in food processing as an antimicrobial agent under regulated conditions.

What It Is

Ozone is a triatomic form of oxygen comprised of three oxygen atoms bonded together. As defined in U.S. federal food regulations, ozone (CAS 10028-15-6) is recognized as an antimicrobial agent permitted for use in food treatment, storage, and processing when applied in gaseous or aqueous form under specified conditions of good manufacturing practice. It is an unstable gas with a characteristic pungent odor, and, due to its high oxidation potential, ozone actively disrupts microbial cells on contact, making it effective for reducing microbial contamination on food surfaces at appropriate levels of exposure. Ozone does not remain in the food after use because it decomposes back to oxygen. In regulatory nomenclature, ozone appears in U.S. Code of Federal Regulations sections 21 CFR 173.368 and 184.1563, where it is described as safe for its intended food uses. Ozone functions technologically by exerting oxidative pressure on microorganisms, thereby serving as an antimicrobial processing agent rather than adding nutritive value. Although ozone occurs naturally in the environment, in the context of food processing it must meet appropriate purity specifications and be applied according to industry standards. The regulatory listings identify its permitted uses and define the constraints under which it may be safely employed in contact with foods.

How It Is Made

Ozone used for food processing applications is generated on site rather than supplied as a stored gas. The most common industrial methods involve passing electrical discharges through oxygen or air (corona discharge) or exposing oxygen to ultraviolet light to facilitate the combination of oxygen molecules into ozone. These processes produce ozone in situ because the gas is highly unstable and cannot be reliably stored for long periods. Commercial generation systems are engineered to produce controlled concentrations of ozone, which are then applied immediately to food surfaces or processing environments. Because ozone decomposes rapidly back to diatomic oxygen, on-site generation minimizes the safety risks associated with storage and long-distance transport. The Food Chemicals Codex specifications referenced in U.S. regulations provide guidance on the purity and identity of ozone for its food uses, ensuring that the generated ozone meets the standards appropriate for antimicrobial use. By design, food-grade ozone production systems integrate safeguards to control output concentration and ensure that ozone exposure remains within regulatory and safety limits during food treatment. Ozone generation is typically coupled with monitoring equipment to control applied doses and to facilitate compliance with industry practices that ensure efficacy while limiting worker and product exposure to ozone levels outside the intended range.

Why It Is Used In Food

Ozone is used in the food industry principally for its antimicrobial properties. Owing to its strong oxidative potential, ozone effectively reduces populations of microorganisms on the surfaces of foods and food contact surfaces, helping control spoilage and improve microbiological safety. Because ozone decomposes into oxygen after reacting with microbes and does not leave chemical residues, it is often considered a "clean" antimicrobial alternative to conventional chemical sanitizers. Processors use ozone in both gaseous and aqueous phases to treat a wide range of commodities, including fresh produce, meats, poultry, eggs, and water used in processing. Its broad-spectrum activity against bacteria, molds, yeasts, and viruses makes ozone a versatile technology for sanitizing processing equipment, wash water, and packaging environments under the conditions set forth in federal regulations. In food processing operations, ozone can also help reduce the reliance on other chemical treatments that may leave residues or require downstream removal steps. Its use aligns with the industry’s interest in meeting food safety standards and achieving microbial control while maintaining product quality and minimizing the presence of residual chemicals on finished products.

Adi Example Calculation

Because ozone decomposes rapidly to oxygen and does not persist in the final food, there is no numeric Acceptable Daily Intake (ADI) established by international regulatory bodies that applies to the intact molecule. As a result, an illustrative calculation cannot be provided using an ADI value. In practice, the safety considerations for ozone in food processing relate to application methods, exposure parameters, and compliance with regulatory good manufacturing practices rather than quantifying chronic dietary intake.

Safety And Health Research

Scientific research on ozone’s use in food processing focuses primarily on its antimicrobial efficacy and its behavior in contact with food matrices rather than on nutritional or systemic health effects from consumption. Ozone’s high oxidative potential disrupts microbial cell walls and essential biomolecules, reducing spoilage and pathogenic organisms on treated surfaces; this action is well documented in food science literature. Because ozone rapidly decomposes to oxygen after application, persistent chemical residues are not expected on treated foods, and risk assessments concentrate on ensuring that ozone is applied in controlled concentrations consistent with regulatory standards and good manufacturing practice. Worker safety concerns, such as occupational exposure limits, are well documented separately from food safety considerations. The absence of an internationally recognized ADI or harmonized global specification reflects the technical difference between ozone and other food additives: it is applied and decomposed at point of use rather than ingested as a component of the finished food. Regulatory evaluations and scientific studies thus emphasize application conditions, contact parameters, and food quality outcomes rather than chronic dietary exposure because ozone does not remain as a discrete molecule in the final product.

Regulatory Status Worldwide

In the United States, ozone is listed in the Code of Federal Regulations as an antimicrobial agent permitted for use in the treatment, storage, and processing of foods, including meat and poultry, under 21 CFR 173.368 for direct food contact applications and under 21 CFR 184.1563 for general food additive listings. These sections describe ozone’s identity, production methods, and the conditions under which it may be used in food processing as an antimicrobial agent under good manufacturing practice. The regulatory language identifies ozone by its CAS number (10028-15-6) and notes its permitted use in gaseous and aqueous phases when consistent with current industry standards of good manufacturing practice. In the European Union, ozone is not assigned an E number for use as a food additive in the same manner as many conventional preservatives and processing aids, and there is limited evidence of a formal EFSA opinion on ozone as a food additive. EFSA has been involved in consultations on ozone’s use as a basic substance for plant protection contexts, but this does not equate to authorization as a food additive in the EU framework. At the international level, authoritative bodies such as JECFA provide evaluation frameworks for food additives generally but do not currently list a specific ADI or specification for ozone in the widely accessible databases. As such, the regulatory landscape outside the United States reflects a more restricted or case-by-case consideration of ozone’s use, and its permitted applications vary by jurisdiction.

Taste And Functional Properties

Ozone itself does not impart a sensory taste to foods because it decomposes to oxygen and does not persist in the treated product once its function as a microbial agent has been fulfilled. When used in aqueous phase, ozone-treated water may carry a transient ozone odor that dissipates quickly as the gas decomposes. In gaseous applications, the pungent smell of ozone is noticeable only during treatment and is not detectable in the final food product after decomposition. Functionally, ozone’s antimicrobial action depends on its oxidative capacity, which is influenced by factors such as concentration, contact time, temperature, and the nature of the food surface. Ozone is unstable and has a short half-life relative to other antimicrobial agents; its efficacy is therefore tied to generating and applying it at the point of use. Because ozone breaks down into oxygen, it does not change the intrinsic composition of the food matrix or create persistent chemical residues that might alter flavor or texture. The decomposition of ozone means that its application must be carefully controlled to achieve the desired antimicrobial effect. Overexposure can lead to oxidative changes in sensitive components, while insufficient exposure may not achieve the targeted microbial reduction. Food processors calibrate ozone applications to balance antimicrobial efficacy with maintenance of quality attributes such as taste, texture, and color.

Acceptable Daily Intake Explained

Acceptable Daily Intake (ADI) is a concept used by regulators to define the amount of a food additive that can be ingested daily over a lifetime without appreciable health risk. Because ozone decomposes to oxygen and does not remain intact in the food after application, there is no internationally established numeric ADI for ozone in the context of food additives. In regulatory practice, the emphasis for ozone is on ensuring that its application as an antimicrobial agent is consistent with prescribed conditions of use and that the gas is generated and applied under controlled conditions that minimize unintended exposure. Ozone’s rapid decomposition means that chronic dietary exposure to the intact molecule itself is not the basis for safety assessments in the same way as conventional additives that persist in finished foods. Therefore, ozone’s regulatory status and permitted food contact conditions serve as practical controls rather than an ADI value.

Comparison With Similar Additives

Ozone’s function and behavior can be contrasted with other antimicrobial agents used in food processing. Chlorine-based sanitizers are commonly used for water and surface disinfection; chlorine persists longer in solution and can form chlorinated by-products that require management, whereas ozone decomposes rapidly to oxygen and leaves no persistent chemical residues. Peracetic acid is another oxidizing antimicrobial that, like ozone, breaks down into benign end products (acetic acid and oxygen). However, peracetic acid can impart sensory changes if residues remain, while ozone’s decomposition products are not a flavor or odor concern once the gas dissipates. Organic acids such as citric acid serve as preservatives by lowering pH and creating hostile conditions for microbes; these agents remain in the food and contribute to flavor, whereas ozone’s antimicrobial role does not depend on altering food composition or taste.

Common Food Applications Narrative

Ozone is widely employed in the food industry to help manage microbial contamination on a variety of products and processing surfaces. In produce operations, ozone-enriched wash water is used to sanitize fruits and vegetables, reducing spoilage organisms and lowering the risk of foodborne pathogens. The addition of ozone in wash systems can help maintain visual appearance and extend the shelf life of fresh produce by reducing microbial load without leaving chemical residues. In meat and poultry processing, ozone treatments are used in gaseous or aqueous form to sanitize carcasses, equipment, and contact surfaces in accordance with regulatory standards. The high reactivity of ozone allows processors to target a broad spectrum of spoilage and pathogenic microbes, contributing to improved safety outcomes when combined with other good manufacturing practices. Ozone’s use as a contact agent on food surfaces or in processing water is governed by prescribed conditions of good manufacturing practice as outlined in U.S. regulations. Bottled water and beverage facilities also use ozone for sanitizing water and critical contact surfaces, helping reduce reliance on chlorine-based sanitizers and minimizing residual taste effects. Across these diverse applications, the common thread is ozone’s role as an antimicrobial agent applied where microbial control is essential and where its rapid decomposition to oxygen aligns with the goal of minimizing residual chemical presence in the final food or beverage product.

Safety & Regulations

FDA

  • Approved: True
  • Regulation: 21 CFR 173.368 and 21 CFR 184.1563

EFSA

  • Notes: No specific EFSA authorization as a food additive was identified from available authoritative sources

JECFA

  • Notes: No specific JECFA specification or ADI entry was found in the authoritative database for ozone

Sources

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