A protection and containment system for co-packaged containers is provided which includes a hollow primary container, a top protector complementally configure to fit atop the primary container, and at least one retainer coupled to the top protector for holding a secondary container. The primary container has a circumscribing upright sidewall and an opening configured for receiving material to be stored in the container. The top protector includes a side wall and at least a pair of spaced-apart opposed risers, most preferably provided as one of four corner modules, the risers extending upwardly from the primary container above the opening and presenting a gap between the risers which is sized and configured for receiving the secondary container. Several retainers can be provided, either to hold the secondary containers in different gaps, or provided in tandem to hold two secondary containers adjacent to one another in or proximate a single gap.