Depends on the industry and application.
In general industrial guys would consider any liquid gas handling as being cryo.
But for specialists they usually are thinking much colder, say 20K or less.
Typically, a temperature whereby air is liquified would clearly be considered to be cryogenic, i.e., 78 K. But, any temperature where skin and tissue damage can readily occur should be included, such as anything below 200 K, but NIST says anything below 150 K should be considered to be cryogenic
There is no absolute boundary, since the word is a human definition, and there is no natural distinction between really, really, cold and really, really, really, cold
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NIST not withstanding, 200 K would make for a plausible demarcation, since 194.7 K is where the first of the common atmospheric gases changes phase. Oxygen is next at 90 K
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