Phosphoric acid is used as an acid catalyst in making ethylene and purifying hydrogen peroxide, in the manufacture of chemicals (ethylbenzene, propylene, cumene), as a bonding agent for refractory bricks, in extracting penicillin and as an analytical agent. It is used as an anti-oxidant in food, as a flavour additive for sharp taste in food (jellies, preserves) and soft drinks (e.g., Coca-Cola), as a tang (Food Additive 338) and for the manufacture of yeasts and gelatine. It is used to manufacture the phosphoric acid electrolyte fuel cell system, and it has been used to treat lead poisoning.