The vapor pressures of tri-n-butyl phosphate (TBP) and dibutylphenyl p
hosphate (DBPP) have been determined from gas chromatographic retentio
n times and from measurement of the equilibrium vapor concentrations.
Also, the partial pressures of these compounds in the headspace of a h
ydraulic fluid were measured. The obtained values have been compared w
ith published data.