60079 "risk of mechanical danger"

[jhc_jr]

I realize this is probably a rather basic question, but I'm new to the field

60079-0(2012+A11:2013) 26.4.2 Resistance to impact lists High and Low test criteria for Risk of Mechanical Danger.

I can't seem to find anything that describes the assessment criteria for Risk of Mechanical danger, or how one would categorize that risk as high or low. There is no definition in 60079-0.

References to other standards that may allude to a definition would be appreciated as well as any direct references.

Thank you in advance

James