Hi, Does anyone know any info. or research on what trolley covering one should be using under the tray of sterile instruments. We currentlly just use the layer of wraps in which the instrument sets are autoclaved in and these are just water repellant and are not water proof , there seems to now be a school of thought that we should always be using a 3rd cover which is completely water proof. This is now what i have to find out about so we can have one gen theatre policy for all our theatres. ------------------