The transport of formaldehyde and ethylene glycol through modern fluorinated membranes is discussed. For a cell configuration proposed for the electrosynthesis of ethylene glycol from formaldehyde, both reactant and product pass through the membranes investigated at a rate of 1 to 2 mol m(-2)h(-1); this is clearly unacceptable and highlights the need for the development of alternative membranes or the design of undivided cell processes for organic electrosynthesis. The paper reports the influence of temperature, current density, and type of membrane on the rate of transport, and it is concluded that the direction and magnitude of the flux of water through the membrane has a strong effect on the transport of the organics.