Which type of records must be kept confidential according to employment laws?

Social security numbers must be kept confidential in accordance with employment laws because they are considered sensitive personal information. The protection of social security numbers is crucial to prevent identity theft and ensure the privacy of employees. Employers are required to handle and store this information securely, complying with regulations that govern personal data protection.

In contrast, while performance evaluations, disciplinary notices, and training certifications can also contain sensitive information and may require some level of confidentiality, they do not have the same stringent legal requirements as social security numbers. These records might be managed according to organizational policies or practices, but they do not carry the same universal legal obligation to maintain confidentiality as social security numbers do.