Phenol contamination in ambient air is a factor which creates health risks for children living in a zone influenced by emissions from a ferrous metallurgy enterprise. Our research goal was to assess specific hapten sensitization in children living under excessive aerogenic exposure to phenol. We performed hygienic assessment of ambient air pollution on territories of pre-school children facilities located at various distances from a zone influenced by the examined enterprise (1 km and 5 km were the test territories No. 1 and 2 accordingly) which emitted phenol thus creating elevated concentrations of the chemical in ambient air being higher than single maximum MPC. Ambient air on a selected reference territory was not polluted with any industrial emissions. The test group No. 1 was made of 99 children (the test territory No. 1); the test group No. 2, 92 children (the test territory No. 2); and the reference group, 95 children (the reference territory). We analyzed phenol contents and levels of IgG specific to phenol in blood of all the examined children. Phenol concentrations in ambient air were higher than its permissible levels on the test territory No. 1, 1.7 single maximum MPC, and the test territory No. 2, 1.1 single maximum MPC. We comparatively assessed phenol contents in blood of children from all three groups. The assessment revealed that children from the test group No. 1 had a hydroxybenzene concentration in their blood which was statistically significantly (р = 0.031) by 1.9 times higher than in blood of children from the reference group. Production of specific G class antibodies was higher than the upper limit of the physiological standard in 60 % and 36 % children living and attending a preschool children facility in zones located accordingly at the minimal and maximum distance an emission source. The research results indicate that a hapten-associated increase in the level of IgG specific to phenol in preschool children is associated with excessive phenol contamination creating a substantial burden on biological media (OR = 14.75; 95 % CI = 6.45–33.73; р < 0.05).