Final answer:
An exception to the ethical standard of maintaining client confidentiality is when there is a risk of harm to the client or others.
Step-by-step explanation:
An exception to the ethical standard of maintaining client confidentiality is when there is a risk of harm to the client or others. In the context of therapists, if a client discloses that they plan to harm themselves or someone else, the therapist has a duty to report and take necessary actions to protect the individual or potential victims. This exception prioritizes the safety and well-being of individuals over confidentiality.