Nonidet P-40

Nonidet P-40 is a nonionic, non-denaturing detergent. Its official IUPAC name is octylphenoxypolyethoxyethanol. Nonidet is a trademark of Shell Chemical Co.
Nonidet P-40 is sometimes abbreviated as NP-40, but should not be confused with a different detergent by the same name NP-40, nonylphenoxypolyethoxyethanol of the Tergitol NP series of Dow Chemicals).
Nonidet P-40 is no longer sold by the chemical company Sigma-Aldrich. Sigma-Aldrich has replaced Nonidet P-40 with IGEPAL CA-630, which is described as a "nonionic, non-denaturing detergent". Sigma-Aldrich claims that IGEPAL CA-630 is "chemically indistinguishable from Nonidet P-40".