Food grade phosphoric acid is added to it as a preservative Al. It's used in a lot of processed foods. TEL Dave, if I correctly remember my high school Chemistry from 50+ years ago, when water is mixed with Carbon Dioxide under pressure, as in the manufacture of soft drinks, a weak solution of Carbonic Acid is formed, not Phosphoric, which is some very mean stuff. Al Messer Gents, You know that when you are driving in a light drizzly rain at night and you get that smeary oil film on your windscreen (windshield in USA)? Well, just pour a wee bit of Coca-Cola on the windshield and the acid (or something) in the drink will remove the oily film in less than one second. It perks werfectly for me or did the last time I used it, which when my car had no windshield washer installed or reservoir was empty. REDNECK MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.