Acids are used in industries to manufacture fertilizers, paints, dyes and man-made fibers, while bases are used in the production of fabrics, cleaning agents and paper. In nutrition, diluted acids are used to dress salads and vegetables, giving food a distinctive taste. For example, vinegar contains 3 percent acetic acid. Citrus fruits have citric acid. Aspirin contains acetylsalicylic acid, and wine has tartaric acid.