In the irradiation of powders it is desirable to utilize completely the radiation beam while assuring a uniform irradiation of the product. When an electron beam is the radiation source, this is usually done by spreading the particles on a conveyor belt with a carefully controlled thickness of product. Non-uniform product thickness and depth-dose variations of the beam make the desired goals difficult to achieve. In the present work, the particulate material (methyl cellulose) was maintained in a fluidized state while the electron beam was injected into the bed. Complete utilization of the beam striking the bed was thus achieved and the product was shown to have been irradiated uniformly. The fluidized bed was operated under both batch and continuous feed conditions. In addition, it was observed that a comparable degradation of the methyl cellulose required only about half the radiation exposure needed with thin layer processing. Factors that may be responsible for this effect are discussed.