In previous work, bauxite residue (BR) was successfully used to improve the heat shielding effect of an epoxy based intumescent coated (IC) steel system. In this work, the effect of the ceramic filler on the corrosion resistance of the intumescent coated steel was investigated using static weight loss immersion test in 5 NaCl solution. Incorporation of BR led to 45 reduction in corrosion rate due to the passivation effect of the metal oxide on the steel-moisture interface. Modification of BR by ball milling further reduced the rate of corrosion by 79. Increased concentration of NaCl to 15 gave a negative effect due to increasing interaction with the surface hydroxyl groups. The ball milled BR IC system however maintained good corrosion resistance due to lower concentration of surface hydroxyl content. © 2018 Author(s).