Sodium dichromate is commonly used in sodium chlorate production to maintain high current efficiency; however, it is also a well documented carcinogen. To reduce the environmental impact, identification of a suitable alternative with similar buffering characteristics to dichromate and without adverse effect on the electrolytic performance of sodium chlorate production is important; sodium molybdate is a good candidate. Molybdate ion and its conjugated acid work as a buffer pair at pH 5-6, a lower and slightly narrower pH window than the typical buffer region of dichromate. Nonetheless, the molybdate buffer works effectively during the electrolytic process by maintaining pH at~5.9. Although the use of molybdate buffer will lower the overpotential of hydrogen evolution reaction (HER) by~100 mV, the average off-gas oxygen content is noticeably compromised at 3.6-4.6%, measured using a pilot cell operated at 3 kA m -2 and 80°C during a 3-day trial. The resulting current efficiency of 91~92% is significantly lower than when dichromate is employed as the process additive (> 96%). Mixtures of different dichromate and molybdate ratio were also investigated in terms of the resulting cathode surface potential.