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Palm C16 methyl ester sulphonate (C16MES) is an anionic surfactant that has the potential as active ingredient in the production of laundry detergent powders.Although C 16MES has been successfully applied in the production of high-density laundry detergent powders (HDDP), it could not be employed directly as it is in the spray drying process for the production of low-density laundry detergent powders (LDDP) without compromising the detergency and other significant properties.This research paper highlights the pilot-scale experimental study, which performed to produce phosphate-flee laundry detergent (PFD) powders incorporated with binary anionic surfactants of C16MES and linear alkyl benzene sulphonic acid (LABSA).Past laboratory experiments revealed that PFD powders resulted from C16MES/LABSA of 50∶50 ratio and of pH 7-8 have good detergency stability upon one-week of continuous heating in an oven at 50℃ with 85% relative humidity.Based on these laboratory results,subsequent experiments were carried in a 5 kg/hr capacity co-current pilot spray dryer using PFD formulations comprising six different ratios of C16MES/LABSA (0∶100, 20∶80, 40∶60, 80∶20 and 100∶0) under the same pH condition.Three PFD formulations were selected for further evaluation based on their characteristics in the spray drying process.The cleaning properties and particle properties of the resulting spray dried detergent powders from these selected formulations were analyzed.Based on the overall evaluation, C16MES/LABSA in 40∶60 ratio was selected as the ideal PFD formulation.Further tests confirmed that spray dried detergent powder (SDDP) from the ideal formulation has high level of biodegradability (60% in 13 d), low eco-toxicity properties (LC50 of 11.3 mg/L) and moderate flowability characteristics (Hausner ratio of 1.27 and Carrs index of 21.3).