The chlor-alkali industries produce caustic soda (NaOH), chlorine (Cl2), and hydrogen (H2) as primary products. In 2021, the global chlor-alkali market was valued at $63.2 billion. The article evaluates the global aspects of chlor-alkali industries and prospects for Bangladesh. The current production capacity of NaOH from the chlor-alkali industries in Bangladesh is around 282,150 metric tons/year (MT/y). The by-products, chlorine (Cl2) of 250,470 MT/y and hydrogen (H2) of 7055 MT/y, are produced domestically. The local demand of Cl2 is 68,779 MT/y. However, there are no systematic utilizations of the residual Cl2 and vented H2, which threatens the sustainability of the chlor-alkali industries. The article prefigures that a 150,000 MT/y PVC plant can utilize 45.2 % of residual Cl2 of chlor-alkali plants, which would be an economical and environmental milestone for Bangladesh. The residual Cl2 can earn revenue of 908 million USD/y, which can be utilized to import ethylene. For the sustainable utilization of vented H2, production of H2O2, fuel cell electric vehicle (FCEV) and H2 fuel-cell-based power plant are the feasible solutions. Thus, for the long-term growth of the chlor-alkali industry in Bangladesh and other developing countries, systematic utilization of Cl2 and H2 is the only feasible solution.