[en] Effective atomic numbers of some dosimetric interest organic compounds, like glucose, ethanol, acetic acid, trichloroethylene, chloroform, benzene, acetone, phenol, chlorobenzene, naphthalene, adenine, alanine, anthracene, carbon tetrachloride, diethyl either and sucrose are calculated using Auto-Z_eff, direct, logarithmic interpolation, ratio, power law and single-value XmuDat methods. The calculated effective atomic numbers are compared with experiment data wherever possible and results show a good agreement. The Auto-Z_eff, direct, logarithmic interpolation and ratio methods are the most suitable for intermediate photon energy (50 keV < E < 20 MeV), where Compton scattering dominates. Mixture law is applicable in intermediate energy region for computation of theoretical effective atomic numbers. Kerma relative to air of the selected organic compounds are also calculated for photon energy 1 keV - 20 MeV. The kerma reaches unity beyond 200 keV and up to 10 MeV. (author)