A treatment for particulate inorganic solids is provided. This treatment, which uses certain organophosphinic compounds, imparts improved physical and chemical qualities including lacing resistance, improved dispersion and decreased chemical reactivity when these treated particulate inorganic solids are incorporated into polymeric matrices. The addition of the organophosphinic compounds of the present invention may flexibly be incorporated into known processes at varying points, and are preferably added downstream of any filtering steps or to a dry particulate inorganic solid.