E211: Sodium Benzoate (Acid Beverage Preservative)

Direct Answer

E211 (Sodium Benzoate) is the sodium salt of benzoic acid, highly soluble and active against yeasts and bacteria in acidic environments (pH < 4.5). INS 211, group ADI is 5 mg/kg bw/day, the standard antimicrobial in carbonated soft drinks and fruit juices.

Source: EFSA ANS Panel (2016) / FDA · Last reviewed Aug 28, 2026

Specs

E-Number Code	E211
INS / Codex Number	INS 211
Functional Class	Preservative (Antibacterial, Antifungal)
Acceptable Daily Intake (ADI)	5 mg / kg body weight per day (as benzoic acid equivalent)
Chemical Formula	C7H5NaO2
Primary Mechanism	In acidic media, converts to lipophilic undissociated benzoic acid which disrupts intracellular pH and anaerobic glycolysis in microbes
Common Target Foods	Acidic soft drinks, sparkling waters, salad dressings, jams, pickles, soy sauce
Dietary Compliance	Vegan, Halal, Kosher
Safety Approval	EFSA Authorized / FDA GRAS (21 CFR 184.1733)

Benzene Formation Avoidance Rule

When sodium benzoate is formulated together with ascorbic acid (Vitamin C, E300) in the presence of transition metal catalysts (Fe3+, Cu2+) and UV light, trace benzene can form. Beverage manufacturers use chelating agents (EDTA) or substitute sorbates to prevent reaction.