4-Nonylphenol

4-Nonylphenol (CAS 104-40-5), also referred to as PNP, p-NP, or simply nonylphenol, is a long-chain alkylphenol produced by the alkylation of phenol with nonene. It serves as a key intermediate in the manufacture of nonylphenol ethoxylates and as a standalone surfactant in industrial formulations.

In textile and leather processing, 4-nonylphenol acts as an emulsifier and wetting agent, reducing interfacial tension to improve dye penetration and bath uniformity. In lubricant and metalworking formulations, it functions as an antioxidant and stabilizer, inhibiting oxidative degradation of base oils under high-temperature operating conditions.

4-Nonylphenol is subject to REACH regulation, with restrictions on use in concentrations above 0.1% w/w in certain industrial and consumer applications under SVHC and Annex XVII provisions. Procurement teams should confirm end-use compliance before sourcing. The material is typically available in drum and IBC packaging.