Phenyl isomer distributions, within current commercial limits of HF and A1CI 3 linear alkylbenzene sulfonates (LAS), have little effect on dishwashing performance in light-duty liquids (LDL), detergency performance in heavy-duty powders (HDP), and interfacial tension value. The most important factor in determining performance differences among commercial LAS samples is carbon chain homolog distribution. Both HF and A1CI 3 LAS perform equally well and can be used interchangeably in high-performance product~ The optimum for foam stability in light-duty liquids shifts towards shorter alkyl chain length as water hardness increases. At 0 ppm water hardness the optimum occurs at C13 ; at 50-150 ppm the optimum moves to C~1 and CI2 ; and above 150 ppm the optimum shifts to include C~0, Ctx and C~2. The detergency performance optimum range in a phosphate built heavy-duty powder at 50 and 150 ppm water hardness includes the C~2 , C13 and C~4 alkyl chain lengths. In a nonphosphate built powder the optimum is similar at 50 ppm hardness to that of a phosphate built powder, but shifts at 150 ppm hardness to include CH, Cl2 and Ct~.