Chemical additives and agents include a wide range of materials added to polymer resins, paints and coatings, adhesives, and other substances to modify specific processing or end-use properties. They include catalysts, wetting agents, levelers, clarifiers, coupling agents, deflocculants, thinners, thickeners, anti-caking agents and other chemicals. Chemical additives and agents are available in many different forms. Choices include inorganic chemicals or salts, organic chemicals or polymers, liquids or solutions, colloids or dispersions, bulk solids or granules, and powders. Some chemical additives and chemical agents are cationic or produce cations. Others are anionic or produce anions. Chemical additives and agents also metal removal agents, water softeners, oxidation inhibitors, anti-oxidants, plasticizers, reaction terminations and retarders, reaction accelerators, release agents, rheology modifiers and flow agents, scale inhibitors, settling agents and flocculants, stabilizers, and anti-degradants. Acids, acidulants, bases, alkali compounds and buffers are used to modify pH levels. Stabilizers are used to impart dimensional stability, color, fragrance, heat resistance, or ultraviolet (UV) stability. Thickeners, thinners, waterproofing additives, hydrophobing agents, surfactants, and wetting agents are also available.