Triisobutyl phosphate (TIBP) is a clear, colorless liquid that is derived from isobutyl alcohol and phosphoric acid. It is used as a defoamer and penetrant in gypsum-based products, such as drywall and plaster. Triisobutyl phosphate reduces the formation and persistence of foam in the gypsum slurry, which can cause defects and cracks in the final product. It also improves the wetting and spreading of the gypsum on the substrate, resulting in a smooth and uniform finish. Triisobutyl phosphate / Tributyl phosphate (TIBP/TBP) can be added to slurries to both inhibit foam formation and destroy existing foam. Both TIBP/TBP supplied in liquid concentrations.