Is Sodium Benzoate Harmful to Humans? A Balanced Review

December 22, 2025 •

3 min read

Over a century ago, the Food and Drug Administration (FDA) first approved sodium benzoate as a food preservative, and it remains widely used today. However, debates about its safety persist, with many consumers asking: Is sodium benzoate harmful to humans? This article provides a comprehensive overview of the science behind this additive.

Quick Summary

Sodium benzoate, an FDA-approved preservative, is generally considered safe in low concentrations, but concerns exist regarding its conversion to benzene when combined with vitamin C, potential links to hyperactivity, and allergic reactions. Health authorities like the FDA and WHO have set acceptable daily intake levels, which most people do not exceed through normal diet.

Key Points

Benzene Formation: When combined with vitamin C and exposed to heat or light, sodium benzoate can form small amounts of benzene, a known carcinogen.
Generally Recognized As Safe (GRAS): The FDA considers sodium benzoate safe at regulated low concentrations (up to 0.1% by weight), and the body metabolizes and excretes it quickly.
Hyperactivity Link: Some studies have suggested a link between sodium benzoate consumption and increased hyperactivity in children, though this is a debated topic.
Allergic Reactions: Sensitive individuals may experience rare allergic symptoms like hives, itching, and swelling, or in some cases, asthma-like symptoms.
Higher Medicinal Doses: In contrast to food-safe levels, high doses of sodium benzoate are used medically for conditions like high blood ammonia, but can cause side effects like nausea and vomiting.
Oxidative Stress: Animal and in-vitro studies have shown that high concentrations may induce oxidative stress, but this is not directly correlated to normal dietary human exposure.

What is Sodium Benzoate and What is it Used For?

Sodium benzoate is the sodium salt of benzoic acid and is primarily used as a preservative to inhibit the growth of bacteria, molds, and yeast in acidic foods and beverages. It is found in products such as sodas, salad dressings, pickles, fruit juices, and condiments. The compound itself does not occur naturally, though benzoic acid is present in some plants like cranberries and cinnamon. Its ability to dissolve easily in products and its effectiveness in acidic environments make it a popular choice for manufacturers.

Beyond food preservation, sodium benzoate has several other applications:

Medicinal use: In larger, carefully controlled doses, it can treat high blood ammonia levels in people with urea cycle disorders. It is also being studied for its potential in treating certain neuropsychiatric and neurodegenerative conditions.
Cosmetics and personal care: It acts as a preservative in products like shampoos, toothpastes, and lotions to prevent microbial growth.
Industrial applications: Sodium benzoate is used as a corrosion inhibitor, such as in coolants for car engines.

Potential Health Concerns with Sodium Benzoate

While regulatory bodies classify sodium benzoate as generally safe (GRAS), certain conditions and sensitivities have raised questions about its potential health risks.

Benzene Formation

One significant concern is its ability to form benzene, especially when combined with vitamin C and exposed to heat or light. This can occur in beverages with both compounds, accelerated by higher temperatures and light. While the FDA has found elevated levels, reformulations generally mean current levels are not a safety concern. However, long-term low-level consumption studies are limited.

Impact on Children's Behavior (ADHD)

A 2007 study suggested a possible link between sodium benzoate, when combined with food colorings, and increased hyperactivity in children. Though more research is needed and results are debated, this has prompted some consumers to limit products with the preservative.

Allergic Reactions

Rarely, some individuals may have allergic reactions to sodium benzoate, including hives, irritation, itching, and swelling. Sensitive individuals might also experience asthma-like symptoms or contact dermatitis from personal care items with the preservative.

Oxidative Stress and DNA Damage

Studies, often using high doses in animal and cell models, have investigated sodium benzoate's effects on oxidative stress and potential DNA damage. Some research indicates high concentrations might increase free radical production, possibly causing cellular damage and weak genotoxic effects in labs. The relevance to typical human dietary intake is unclear.

Regulatory Standards vs. Individual Concerns

Health organizations regulate sodium benzoate use, but these may not cover individual sensitivities or cumulative long-term effects. A comparison of perspectives follows:

Comparison of Safety Perspectives


Feature	FDA/WHO Regulatory Stance	Individual & Alternative Health Perspectives
Safety Classification	Generally Recognized As Safe (GRAS) within approved concentration limits (e.g., 0.1% by weight).	Caution is advised due to potential health risks, especially from long-term consumption and cumulative exposure.
Benzene Formation	Acknowledges the risk but states that current levels in reformulated products do not pose a safety concern.	Emphasizes the need to avoid products combining sodium benzoate with ascorbic acid (vitamin C), as benzene is a known carcinogen.
Recommended Intake	Acceptable Daily Intake (ADI) is 0–5 mg per kg of body weight, which is rarely exceeded through a typical diet.	Proponents of "clean label" trends recommend minimizing consumption of processed foods and additives regardless of official limits.
Metabolism	The body rapidly metabolizes and excretes it via urine within 24 hours, limiting accumulation.	High doses used in medicinal treatments can have side effects and potential metabolic disturbances.

Conclusion: Navigating the Sodium Benzoate Debate

Regulatory bodies like the FDA consider sodium benzoate safe within regulated levels. Concerns exist regarding benzene formation with vitamin C, heat, or light, though manufacturers have largely addressed this. Some evidence links it to hyperactivity in sensitive children and rare allergic reactions. Animal studies suggest potential oxidative stress at high doses.

For consumers, a balanced approach is best. Avoiding all products isn't necessary for most, but those with sensitivities or who want to reduce intake can check labels, especially for products with ascorbic acid. Reducing processed food intake is an effective way to lower exposure. Staying informed and listening to one's body is key as research continues.

Frequently Asked Questions

Sodium benzoate itself is not classified as a carcinogen. However, when combined with ascorbic acid (vitamin C) in certain acidic beverages and exposed to heat or light, it can form benzene, which is a known carcinogen.

You can minimize exposure by checking ingredient labels and avoiding products that list both sodium benzoate and ascorbic acid (vitamin C) or erythorbic acid. Choosing fresh foods and less-processed products is another effective strategy.

Yes, in a small percentage of sensitive individuals, sodium benzoate can cause allergic reactions. Symptoms can include skin rashes, hives, swelling, and sometimes asthma-like respiratory issues.

Some studies, particularly older research, have suggested a link between sodium benzoate and increased hyperactivity in children, often in combination with artificial food colorings. While controversial, some choose to avoid products with this additive based on these concerns.

The FDA classifies sodium benzoate as 'Generally Recognized As Safe' (GRAS) at concentrations up to 0.1% in food. They monitor benzene levels and have worked with manufacturers to reformulate products when issues have arisen.

The human body does not accumulate sodium benzoate. It is metabolized in the liver and kidneys, where it is converted into hippuric acid, which is then excreted in the urine, typically within 24 hours of consumption.

Sodium benzoate is most effective in acidic environments, so it is frequently used in products like carbonated soft drinks, salad dressings, pickles, fruit juices, and jams to prevent spoilage.