2-Phosphonobutane-1,2,4,-tricarboxylic Acid (PBTC) is a very effective scale inhibitor used in various industrial applications. Due to its higher performance properties it is a very cost effective inhibitor compared to standard Phosphonates such as HEDP/ATMP. This is mainly due to superior stability to chlorine, bleach and bromine. In cooling water PBTC performs well at high PH or temperatures. It further shows high effectiveness in high alkaline solutions such as industrial cleaners.