Meh - not funny. Many of the IEC standards (e.g. 60598.1) classify everything over 4VDC as hazardous live - because the "human body equivalent" test circuit has a 2kOhm DC resistance, and the touch current limit on a lot of things is 2mA. There is a second clause saying that apart from the touch current limit, anything over 34V is hazardous live. I believe that the writers of the standard intended things to be classified as live if the touch current was over 2mA AND the voltage was over 34V, but somewhere along the way the AND got left off, then some numpty inserted an OR instead. Therefore 5V power supplies are a shock hazard. One very expensive test lab even told me that my 0V (ground) wire was a shock hazard too, because it was the "neutral" for the "live"
+5VDC supply!Hint: If you can design your product with no earth connection to the logic, then you will pass, as their "human body model" has one side grounded, and they probe one part at a time. If you do need an earth connection to your logic (maybe for shielding etc.), then run your TTL logic etc. from +/- 2.5VDC supplies, then you will also pass.