Charlie Talley: When I developed Star in the late 60's (yes I am that old) it was tested against S. aurous, E. coli, L. bacillus, A. Niger and a few other nasty bacteria. All were at 10 to 30,000,000 colonies per cc. The contact time was at 30, 60, and 120 seconds. The end result was 10 to 30 colonies per cc after 30-second contact time and 0 after 60 seconds of contact time. Since our EPA will only recognize the 120-second contact time that is why it is on our label. So as you can see it is very effective with just a 20 second contact time.
The ingredients that are in Star San are based on food grade or G.R.A.S. materials (Generally Recognized as Safe). They are phosphoric acid, dodecyl benzene sulfonic acid (DDBSA), propylene glycol, and a coupling agent. When it is diluted to 300 ppms one ounce per 5 (US) gallons of water or 1.5-1.6 mls/liter the actives are 300 ppms of DDBSA and 930 ppms of phosphoric acid. This will produce an end pH of 2.5 to 3.5 (depending on the alkalinity of the water used for make up.
