Nowadays, food manufactures use synthetic additives in their food products and in this way is increasing consumers’ desire to eat fast and processed foods which generate the appearance of diet-related diseases and the adverse effects of many of these chemical additives. Sodium benzoate (E211) is a synthetic additive which is widely used in food. It is a salt of benzoic acid which is used in the food against bacteria, fungi and yeast. Generally, sodium benzoate is used as a preservative in soft drinks, margarine, salad dressings, marinades, cider, pickles, fruit salad, wafers, bakery products, jams, jellies, juices, biscuits, cakes and muffins, tomato paste and soy sauce, etc. International data show that the world’s production of benzoic acid is equal to 638,000 tons annually and the available sodium benzoate around the globe is 100,000 tons. Seventy percent of this amount of sodium benzoate can be used as a preservative. The Joint Committee of the World Health Organization (WHO) and Food and Agriculture Organization (FAO) of the United Nations on food additives (JECFA) reported a limit on the amount of sodium benzoate, which was 0 - 5 mg/kg. In Europe, this amount is 0.015 to 0.5% and in America and Iran this amount is 0.1%. A wide range of international studies revealed its damage on health status. In this context, different doses of sodium benzoate administration can generate some toxic effects on animal’s health (weight loss, embryotoxic and fetotoxic effects, etc.) and also on human’s health (urticaria, asthma, rhinitis or anaphylactic shock, etc).