The present study ascertained air quality (AQ) of chemical stores and level of alterations in erythrocyte oxidative stress biomarkers of storekeepers exposed to laboratory/industrial chemicals in Owerri, Imo State, Nigeria. Erythrocyte percentage methaemoglobin (%MetHb), reduced glutathione (GSH) concentration, thiobarbituric acid reactive substances (TBARS) index and H 2 O 2 induced erythrocyte haemolysis of participants were measured by spectrophotometric methods. The air levels of CO, NH 3 and NO 2 in the chemical shops were below Environmental Protection Agency (EPA) minimum standards. Particulate matters (PM) of both control and test air samples were within EPA standards. Erythrocyte %MetHb of test participants represented an increase of 61.81% compared to the control participants ( p > 0.05), whereas erythrocyte GSH concentration of test participants showed significant difference ( p < 0.05). Levels of H 2 O 2 induced erythrocyte haemolysis was significantly (p < 0.05) higher than those of the corresponding control participants. The ratio of erythrocyte TBARS index of the test to the control participants was 1.4:1 approx.; p < 0.05. The present study showed that the gas substances in chemical stores in Owerri compromised AQ with attendant potentials to cause oxidative stress and hazardous consequence to the storekeepers.