Butyl sodium sulfate-D9 is a labelled analogue of Butyl sodium sulfate (B693875). Butyl sodium sulfate is the sulfate salt of Monobutyl sulfate (M525130). Monobutyl sulfate is used as a wetting agent in the mercerization (a treatment that gives cotton its shiny appearance and also functions to increase its strength) of cotton. Monobutyl sulfate is also used in the polymerization of tetrahydrofuran.