sodium benzoate

What is Sodium Benzoate?

Sodium benzoate, known by the food additive code E211, is a key component in preserving the quality of products across the food, beverage, and cosmetics industries. This compound is supplied as a white, odorless, crystalline powder and is synthesized chemically by reacting benzoic acid with sodium hydroxide. This reaction yields a product with significantly higher water solubility, making it exceptionally suitable for use in various formulations, particularly in low pH (acidic) environments.

Although sodium benzoate itself does not exist in nature, its parent structure, benzoic acid, is widely found in the plant kingdom. This acid naturally occurs in fruits and spices such as cranberries, plums, apples, cinnamon, and cloves. Furthermore, benzoic acid can also be spontaneously produced as a byproduct during the natural fermentation process of certain dairy products like yogurt.

 

Physical and Chemical Properties of Sodium Benzoate

Sodium benzoate, identified as E211 with the chemical formula C7H5NaO2, is a chemical compound with specific physical characteristics. In its pure state, the material appears as a white to colorless powder or crystals that are nearly odorless. Its molecular weight is 144 g/mol, and with a density of 1.497 g/cm3, it is considered a relatively dense substance. Regarding thermal stability, sodium benzoate has a high melting point of approximately 410ºC, indicating its stability under normal temperature conditions.

Chemically, sodium benzoate is primarily recognized for its solubility and its application in acidic environments. It exhibits high solubility in water and even in less common solvents like liquid ammonia. However, its most critical property is related to its function as a preservative: in aqueous solutions, the pH of sodium benzoate ranges between 2.5 and 4. This mildly acidic nature allows it to become more active in acidic food environments, acting as an effective antimicrobial agent because, under these conditions, it converts into its active form: benzoic acid.

 

Production Method of Sodium Benzoate

The large-scale production of sodium benzoate is typically achieved by the neutralization of benzoic acid with a sodium hydroxide NaOH solution. There are two main routes for the synthesis of benzoic acid, which differentiate the industrial production methods for this preservative. One route involves the oxidation of toluene using nitric acid, which ultimately yields benzoic acid. The alternative route is the hydrolysis of benzotrichloride, which is then completed by the addition of a mineral acid. After preparing the benzoic acid, it is added to the sodium hydroxide solution, where the reaction occurs, resulting in sodium benzoate and water. Finally, the pure sodium benzoate salt crystals are isolated and collected through the evaporation of the aqueous solution.

 

The Importance and Applications of Benzoic Acid and Sodium Benzoate

Benzoic acid is an effective food preservative in its own right, but the use of its sodium salt form (sodium benzoate) significantly improves the compound's solubility and facilitates its application. Although sodium benzoate does not occur naturally, the parent benzoic acid is found in numerous food items, including tomatoes, apples, various berries, plums, and melon. Besides its central role in preserving the quality of foods and beverages, sodium benzoate is also used in the production of medicines, cosmetics, and personal care products, as well as in some industrial applications, due to its antimicrobial properties.

 

Application in the Food Industry as a Food Preservative

Sodium benzoate, indicated by the code E 211 on food product labels, is recognized as a very common and safe food additive. Its primary role is due to its potent antifungal and antibacterial properties, which effectively prevent product spoilage. For this reason, it is added to food items in pre-determined doses as a preservative to inhibit the growth of yeasts, molds, and bacteria. Health organizations have set the acceptable daily intake (ADI) between 0 to 5 mg per kilogram of body weight, and consumption within this limit is considered safe. This preservative is often used alongside compounds like dextrose to preserve various beverages and jams.

Preservatives

A wide variety of preservatives are designed to protect products from bacterial, mold, and fungal contamination, with the primary reason for their diversity being differences in their spectrum of activity. Some of these substances, such as alcohols, parabens, and formaldehyde, have a broad spectrum of action and are capable of eliminating a large range of microorganisms, making their presence common in cosmetic and personal care products. In contrast, preservatives like sodium benzoate and potassium sorbate have a more selective activity; they are highly effective against yeasts and fungi but have less impact on bacteria. Therefore, to achieve maximum protection against various types of microbes, formulation specialists often use a combination of several types of preservatives to create a comprehensive and complete protective spectrum.

 

Pharmaceutical Application

Sodium benzoate has diverse applications in the field of treatment and pharmaceuticals, and it is even approved as a medication. It is used as a preservative in some pharmaceutical formulations, particularly liquid medicines such as cough syrups. It also acts as a lubricant in tablet production to give them a clear and smooth appearance and to increase their disintegration rate after swallowing. Therapeutically, the compound is prescribed for the management and treatment of high ammonia levels in the blood. Furthermore, research suggests its use in treating some neurological and psychiatric disorders, including major depressive disorder, schizophrenia, and autism spectrum disorder. However, some critics believe that excessive consumption may have detrimental effects, such as mutagenic effects, stress, hormonal disruption, and reduced fertility; for instance, high doses can cause allergic reactions and exacerbate asthma symptoms. In some cases, it is used in combination with caffeine to treat specific headaches and depression.

 

The Role of Sodium Benzoate in Skincare Products

In the formulation of cosmetics and personal care products, including skincare items, sodium benzoate primarily functions as a preservative agent. Its main duty is to inhibit microbial growth; this means it prevents the unwanted proliferation of bacteria and fungi in the product to avert spoilage and contamination. However, it is important to note that this compound typically does not directly kill microbes (it does not have a killing property) but merely inhibits their growth.

 

Dosage of Sodium Benzoate

According to the recommendations of the Food and Drug Administration (FDA), the daily intake of sodium benzoate in food products must remain within a safe range. This acceptable safe limit for human consumption is set between 0 and 5 mg per kilogram of body weight. Adhering to this dosage ensures that the consumption of this preservative does not pose a health risk.

 

Advantages of Sodium Benzoate

The advantages of sodium benzoate include extending product shelf life without the need for refrigeration, reducing food waste, and lowering production costs. It is a safe, inexpensive, and effective agent in acidic environments. In pharmaceuticals, it reduces ammonia levels and improves symptoms of schizophrenia by up to 21%. Environmentally, it is biodegradable and meets the global demand for ready-to-eat foods, which strengthens the industry's economy.

 

Side Effects of Sodium Benzoate

One significant debate regarding sodium benzoate relates to the simultaneous presence of this substance with Vitamin C (ascorbic acid) in formulations, particularly in beverages. This combination may lead to the formation of a controversial substance called benzene. It is noteworthy that sugar-free (diet) beverages are more likely to produce benzene compared to sugar-containing beverages, as the presence of sugar can slow down this chemical process. However, according to standards set by the EPA (Environmental Protection Agency), the maximum permissible level of benzene in beverages is set at 5 parts per billion (ppb). Research indicates that amounts below this standard limit will not have a significant impact on human health, especially concerning an increased risk of cancer.

 

Purchasing Sodium Benzoate

Persia Kamandar Paitakht Trading Company, as one of the reputable suppliers of sodium benzoate in the market, has designed its purchasing process with the aim of complete transparency and product quality assurance. By emphasizing timely delivery and providing precise technical specifications, the company intends to maintain a reliable and safe supply chain of sodium benzoate for industries such as the production of detergents, paints, resins, and industrial applications.

Persia Kamandar Paitakht Company, as one of the pioneers in chemical raw material supply in Iran, is an importer and distributor of various preservatives and industrial and food additives. By offering high-quality sodium benzoate with international standards, the company helps the food, beverage, and canning industries produce their products with longer shelf life and higher quality. Persia Kamandar's commitment to supplying premium food and chemical raw materials and providing customer-centric services makes it a trusted partner for professional manufacturers.

Is Sodium Benzoate Carcinogenic?

Generally, sodium benzoate (E211) is considered a safe compound when used alone and within authorized doses. However, in the presence of Vitamin C (ascorbic acid), a chemical reaction can occur that leads to the formation of benzene. Benzene is recognized as a carcinogen, but its formation and concentration in food products are usually very low and below the permissible limits set by health organizations.