Encapsulation involves placing the pharmaceuticals in a plastic or steel drum. When the drum is 90% full, fill the remaining space by pouring a media such as cement/lime mortar, plastic foam or bituminous sand. Seal the drums and then place at the base of the working face of a landfill.
For cytostatics use a ratio of 40% cement, 30% water and 30% waste by weight well mixed and allow to set for between 7 and 28 days prior to landfill. This will form a firm immobile solid block in which the wastes are relatively securely isolated. The most economical ratios to achieve a minimum permeability of the blocks should be determined by experiment.