One problem with research on nanoparticles production is the lack of scalability from laboratory to levels of production necessary for commercial or industrial applications at low cost. Several methods, which often involve the use of chemicals, have been employed to produce silica nanoparticles from rice husk, but output levels cannot be said to meet industry requirements. This paper reports the design of a novel method - hydro thermo-baric processing, which was used to produce high purity silica from rice husk. The process factors were optimised using the method of factorial design of experiments. The produced nanoparticles were characterised using XRF, XRD, FESEM and EDX. XRD results show that the silica produced, which by XRF analysis had approximately 99 purity, is amorphous in nature. FESEM images showed that the particles have nanometric size. However, EDX results show an increase in residual carbon in the silica, with increase in the processing temperature. Copyright © 2012 Inderscience Enterprises Ltd.