The large particle count (LPC) of fumed silica slurries was evaluated and correlated with scratch counts created on SiO2 films by table-top, chemical-mechanical planarization (CMP). Particle sizing results obtained by static light scattering, capillary hydrodynamic fractionation, and dual-sensor single particle optical sensing (SPOS) pointed to the latter as the superior method for quantitative analyses of the LPC. Dual-sensor SPOS is a new technique that determines the LPC on a silica sphere-equivalent, light-scattering diameter scale for particles as small as 0.469 mu m. LPC measurements used in combination with dark-field optical microscopy for scratch metrology afforded linear correlations between scratch counts and the LPC. Particles producing scratches had silica sphere-equivalent, light-scattering diameters exceeding 0.68 mu m. Inclusion of these particles in the LPC produced a two-fold increase in the number of scratch-forming particles in the correlation relative to correlations generated via single-sensor SPOS measurements of LPC. Experimental uncertainty in scratch counts limited the correlation as a scratch predictor. Slurries differing in LPC by a minimum of 1.8 x 105 particles/g(slurry) had statistically different predicted scratch counts at the 95% confidence level. Additional method development is needed to extend LPC-based scratch prediction to other CMP processes producing scratch defects. (c) 2006 The Electrochemical Society.