solution. It is the yield value that allows particles to remainin suspension. Fumed silica is one of the agents for gelling the oil phase 16It shouldbenotedthat fumed silica is very light and dusty, and special protective measures should be taken by compounders. The use of ethylene co polymers is another method of creating gelled oils. 17 Both methods form gels that break easily under shear stress, yet recover viscosity and yield quickly over time, which is to say they have thixotro pic properties. they are consid- ered a desirable medium for supporting and suspending particles in scrub for mulations. The amount of fumed silica or ethylene copolymers varies accord- ing to oil type and the desired consis- tency of the final product 16, 17 Other oil thickening agents are quaternium-18 bentonites or stearalko- nium bentonitesc, d 18, 19 and Rhus verniciflua peel waxe.20 These gelling agents also impart yield to the continuous phase and thus will suspend salts or sugar