NIST SP 800-88:
> "While most devices support some form of Clear, not all devices have a reliable Purge mechanism. For moderate confidentiality data, the media owner may choose to accept the risk of applying Clear techniques to the media, acknowledging that some data may be able to be retrieved by someone with the time, knowledge, and skills to do so. Purge (and Clear, where applicable) may be more appropriate than Destroy when factoring in environmental concerns"
FIPS 199:
> "Confidentiality High: The unauthorized disclosure of information could be expected to have a severe or catastrophic adverse effect on organizational operations, organizational assets, or individuals.
NIST SP 800-60 v2r1
> " Impact level is usually high where safety of major critical infrastructure components or key national assets is at stake."
This is to say, unless someone is going to die, the confidentiality impact is probably moderate, and the risk-balanced approach in 800-88 is cryptographic erase, purge, or maybe even just clear.