Described is a deduplicated storage system that may perform a focused sanitization process by reducing the number of data storage containers that must be sanitized. The system leverages additional characteristics of the files that need to be sanitized such as an initial storage date (e.g. data breach date) of when a sensitive file (e.g. file to be sanitization) was actually stored on the deduplicated storage system. By maintaining a creation date of data containers, the system may limit sanitization to those containers having a creation date on or after the initial storage date of the sensitive file. Accordingly, the system is capable of performing a more focused overwriting of data thereby improving the overall efficiency of the sanitization process.