NP-40 (also known as Tergitol-type NP-40 and nonyl phenoxypolyethoxylethanol[1]) is a commercially available detergent with CAS Registry Number 9016-45-9.

NP-40 is an ethoxylated nonylphenol for non-ionic surfactants and can act as emulsifier and demulsifier agent.

NP-40 has applications in paper and textile processing, in paints and coatings, and in agrochemical manufacturing.

Care should be taken to avoid confusing NP-40 with Nonidet P-40 (octyl phenoxypolyethoxylethanol) which is currently out of production.

Nonidet P-40 ("Non-Ionic Detergent") was originally manufactured and trademarked by the Shell Chemical Company,[2] but was phased out of production in the early 2000s.