Experimental gas-liquid mass transfer data from a system where single bubbles are kept stationary by a low turbulence downward liquid flow are compared with predictions from theoretical models which take turbulence into account. The data clearly show that, for the turbulence intensities at play, turbulence does not affect mass transfer. Higbie's equation with contact time t(e) = d/u may be used for the calculation of the gas-liquid mass transfer coefficient of clean bubbles in systems with levels of turbulent kinetic energy dissipation of, at least, up to epsilon similar to 0.04 m(2) s(-3). (c) 2005 Elsevier Ltd. All rights reserved.