A calculation procedure to determine the influence of the silicone volume fraction on the physical absorption of VOCs in water/silicone oil mixtures is presented (eta(silicone) oil = 5 mPa s). It is based on the "equivalent absorption capacity" concept previously developed by Dumont et al. (2010)111 and applied to a countercurrent gas-liquid absorber. The calculation procedure is first applied to three VOCs: dimethylsulphide (DMS), dimethyldisulphide (DMDS) and toluene, and then generalised to other VOCs. The influence of VOC partition coefficients (H-voc,H-water and H-voc,H-solvent) and the ratio MR = H-voc,H-water/H-voc,H-solvent is shown. For VOCs having a much higher affinity for silicone oil than for water (m(R) > 20 as for DMDS and toluene). it is preferable to use pure silicone oil rather than water/silicone oil mixtures for absorption. (C) 2011 Elsevier B.V. All rights reserved.