Triton X-100 (C14H22O(C2H4O)n) is a nonionic surfactant that has a hydrophilic polyethylene oxide chain (on average it has 9.5 ethylene oxide units) and an aromatic hydrocarbon lipophilic or hydrophobic group. The hydrocarbon group is a 4-(1,1,3,3-tetramethylbutyl)-phenyl group. It is closely related to IGEPAL CA-630 or erstwhile Nonidet P-40, which might differ from it mainly in having slightly shorter ethylene oxide units. Thus Triton X-100 is slightly more hydrophilic than Igepal CA-630