The pulp and paper industry is the sixth largest polluter discharging a variety of gaseous, liquid and solid wastes into the environment. This pollution mainly arises due to chemicals used during production, so this study compared these two chemicals to determine the better one for a cleaner production process. A dewatered kenaf stem was cooked in the 20, 60 and 90% concentrations of formic acid and sodium hydroxide at time intervals of 1, 2 and 3 h to compare the solids (total suspended solid, total dissolved solid and total solid) of their effluent for environmental friendliness. After examining the whole concentrations and the time intervals, 60% concentration of the acids at 2 h pulping gave better pulp on physical examination. When the solids of the effluents of the two chemicals were analyzed, formic acid effluent had a TSS of 5768 mg/L, TDS of 54088 mg/L and TS of 59855 mg/L, while that of sodium hydroxide was 6053 mg/L for TSS, 96628 mg/L for TDS and 102680 mg/L for TS. This study showed that pulping of kenaf stem with 60% formic acid for 2 h has effluent that is greener than the use of sodium hydroxide of the same concentration at the same duration.