4.16. The conduct of monitoring should not degrade the performance of barriers. The design of the monitoring programme should therefore consider the need for subsequent dismantling of instrumentation. Special attention should be given to the feasibility of removing devices and cables that could lead to detrimental effects (e.g. by introducing materials to the system that can chemically interact with the system components) and of sealing properly monitoring access holes in order to avoid the formation of preferential release pathways. It should be demonstrated either that any remaining physical links (such as wiring) respect this constraint or that such links can be removed, leaving an undisturbed barrier once monitoring is completed.