718 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS studied by Hills, Petley and Roberts (12), who found that olfactory proper- ties of a wide range may be enhanced by radiation. In practice the suitability of radiation for the treatment of individual preparations will be determined by direct experiment because of com- plexities of formulation usually involved. Estimation of the maximum dose a product will tolerate is usually the first step in evaluation of this method of sterilization. Facilities for carrying out the necessary irradiations are readily available at Harwell. RADIATION PLANT OPERATION Plant description- The package irradiation plant with a continuous conveyor system operated at Wantage Research Laboratory is shown in Figs. 2(a) and 2(b). I,'2 Figure 2(b). Diagrammatic representation of the 'continuous' plant illustrating the route taken by boxes through the cell.

_Figure oe(a). The 'continuous' package irradiation plant at Wantage Research Laboratory currently containing 500 kCi of cobalt-60. Facing page 718