A lot of the rules pertaining to working in live panels have to do with "fingersafe" devices. But what exactly is a fingersafe device when it pertains to the NFPA and OSHA.?

I believe it would be important to be able to determine immediatlely whether a device is fingersafe or not.

How big can the hole be on the terminal screwdriver... 1/8", 1/4" or what?