In neem essential oil incorporated chitosan/0.5% ZnO nanocomposites film, WVP values further decreased from 0.67 to 0.41 mg/cm2 /h due to the reason that neem oil is more hydrophobic in nature, in addition reaction between functional groups in chitosan and OH- group present in azadirachtin interact more effectively and reduces the number of hydrogen groups responsible for hydrophilic nature present in water vapour