The primary use of NP is as an intermediate in the manufacture of NPEs. NP may also be reacted to form tris(4-nonyl-phenyl) phosphite (TNPP), an antioxidant used to protect polymers such as rubber, vinyl, polyolefins, and polystyrenics. TNPP is also used as a stabilizer in plastic food packaging. Barium and calcium salts of NP are used as heat stabilizers for polyvinyl chloride (PVC). NP is also used as a catalytic diluent in epoxy resins.
Products containing NPEs are used in many sectors, including textile processing, pulp and paper processing, paints, resins and protective coatings, oil and gas recovery, steel manufacturing, cleaning products, degreasers and detergents, cosmetics, paints, pest control products and power generation. These products have numerous applications, including controlling deposits on machinery, cleaning equipment, and scouring fibres; as wetting and de-wetting agents; in dyeing and machine felt cleaning and conditioning; and in product finishing.