Sodium benzoate is a preservative. It is bacteriostatic and fungistatic under acidic conditions. It is used most commonly in acidic foods such as salad dressings (vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (vinegar), and condiments. It is also used as a preservative in medicines and cosmetics. As a food additive, sodium benzoate has the E number E211. It is also used in fireworks as a fuel in whistle mix, a powder that emits a whistling noise when compressed into a tube and ignited. The fuel is also one of the fastest burning rocket fuels and provides a lot of thrust and smoke. It does have its downsides: there is a high danger of explosion when the motor is pressed because of the fuel’s sensitivity to impact. 2 pounds of material.