What must be done to all materials containing classified information to protect national security?

To protect national security, materials containing classified information must be properly destroyed when they are no longer needed or when they reach the end of their retention period. This ensures that sensitive information does not fall into unauthorized hands and is disposed of in a manner that complies with established security protocols. Proper destruction may involve shredding, degaussing, or other methods that render the information irretrievable, thereby maintaining confidentiality and safeguarding national interests.

Archiving, transferring to an agency like the NSA, or conducting audits, while relevant to information management and security practices, do not directly address the need to eliminate the risk of classified information being accessed or retrieved after its intended purpose has been served. Proper destruction is a critical step in minimizing the potential for compromise of sensitive national security data.