Sodium Benzoate: Definition, Uses, Safety & More

What exactly is sodium benzoate? It is the sodium salt of benzoic acid, which is often used as a preservative and anti-corrosive agent in a variety of industries.

As noted in the U.S. Library of Medicine's ChemIDPlusAdvanced database, some synonyms for sodium benzoate are: Benzoic acid, sodium salt; Antimol; Benzoan sodny; Benzoate of soda; Benzoate sodium; Benzoesaeure (na-salz); Natrium benzoicum; and Sobenate.

CAS Number: 532-32-1

Chemical Formula: C₇H₅NaO₂

Due to sodium benzoate's preservative and antifungal properties, it is often used in conventional and even some green cleaning furniture polishes, toilet bowl cleaners, dishwashing detergent gels, carpet cleaning products, upholstery cleaners, and dishwasher cleaners.

Sodium Benzoate can also be found in a multitude of other industries:

• Auto care: antifreeze
• Arts & Crafts: liquid soap colorants
• Food: sodas, other carbonated beverages, fruit juices, salad dressings, condiments, etc.
• Laundry: starches
• Medicine: IVs (e.g., when caffeine is administered according to the Institute for Safe Medication Practices) and medicines (e.g., liquid cough syrups, liquid acetaminophen, amoxicillin, and medicinal creams)
• Personal Care: hair (e.g., shampoos, colorants, conditioners, and hairsprays) dental (e.g., mouthwashes, toothpastes), skin (e.g., body and facial washes, sunscreens, deodorants), and baby care products (e.g., baby wipes)
• Pet Care: dental products

To see if certain products you use contain sodium benzoate, try searching these databases using the chemical name, CAS number, or one of its synonyms (noted in the section above):

• The Environmental Working Group's (EWG) Guide to Healthy Cleaning
• The EWG's Skin Deep Cosmetic Database
• The Good Guide
• National Institute of Health's  Daily Med
• National Institute of Health's Dietary Supplement Label Database
• The National Library of Medicine's Hazardous Substances Data Bank
• U.S. Department of Health and Human Services Household Products Database

When a chemical is used in pharmaceutical preparations, personal care products, or as a food additive, it is monitored by the U.S. Food and Drug Administration (FDA). For cleaning and industrial uses, it is monitored by the Environmental Protection Agency (EPA).

Sodium benzoate is considered a "Generally Regarded as Safe" (GRAS) food additive by the FDA. However, it has been associated with hyperactivity disorder as noted in this article by Mayo Clinic Staff: "ADHD Diet: Do Food Additives Cause Hyperactivity?' Also, when benzoate is combined with ascorbic acid in carbonated soft drinks, sodium benzoate forms the potent carcinogen benzene. Upon a 2007 review of this problem by the FDA, many levels of benzene were found to be below acceptable limits, but in some cases they were not, in which case drink manufacturers were required to reformulate their products. Sodium benzoate may also be a problem when used medicinally for low-birth-weight infants as noted in a 1992 U.S. Pharmacopeial Convention article cited in the Hazardous Substances Database (HSDB).

With regard to its use as a pesticide, which includes household cleaning products, sodium benzoate is considered a "minimum risk pesticide" by the EPA as noted in this article, because it is "demonstrably safe for the intended use." However, Scorecard, a pollution information guide that is part of the Good Guide, notes sodium benzoate, may be a suspected cardiovascular, blood, gastrointestinal, liver, kidney, neurotoxicant, and skin or sense organ toxicant, but that toxicology data is lacking.

According to the National Institute for Occupational Safety and Health's (NIOSH) International Chemical Safety Card (ICSC) on sodium benzoate, breathing in sodium benzoate can cause respiratory symptoms, such as coughing. Contact with the eyes can result in redness and skin contact may cause a "reversible rash." Also, ingesting sodium benzoate can cause nausea, vomiting, and abdominal pain. Due to these concerns, NIOSH suggests preventive measures for those working with sodium benzoate, such as protecting the skin and eyes and avoiding inhalation of dust.

Sodium benzoate is not expected to persist or bioaccumulate in the environment and according to the EPA, it is considered a "minimum risk pesticide" (see section above for more info). So it could be considered fairly eco-friendly.

Over one million pounds of sodium benzoate are produced annually in the U.S. alone according to Scorecard.

Sodium benzoate is a widely used chemical that is hard to avoid, but there are products that don't contain this synthetic preservative. Instead, they use natural preservatives extracted from plants, such as rosemary, thyme, and camellia sinensis (the plant from which green tea is made). Preservatives extracted from other natural sources, such as microorganisms and animals, are another possibility as noted in this article by Food Safety Watch. So, if you'd like to eliminate your exposure to this man-made chemical, greener alternatives definitely exist.