John (Reno) alluded to this being it's own topic so I responded here. Personally, after seeing seeing a guy's wedding band glowing red hot on his finger, I don't wear any metal at all. If this was a computer room that banned all drinks this guy might have lost his finger completely. He was saved by a Big Gulp. As it was he still has a scar that will never go away and I will never get that smell out of my mind. That was just 3 volts at about 100a but the same can happen at 120v, and <3a ... even if you don't get electrocuted. Why wear electrodes on your body?
That's the point ... metal can be a safety concern, especially in an arc flash situation.
When you see an arc flash video, all those sparkling bits are droplets of molten metal. The metal need not be jewelry .... even zipperz, belt buckles, and eyeglass frames contribute to the liquid shrapnel.
Some 'body' metal you can't do anything about ... like braces and dental fillings. I'd wager that the earings can be left in the locker, though.
Nor does the "oops" episode need to be dramatic. If you've ever ruined a pair of cutters by cutting into a live wire ... take a close look at the cutters. It's likely you'll find little droplets of copper fused into the steel of the tool at some distance from the new notch in the cutting edge.
I know someone who sustained the same injury, changing the battery on a truck. In his case the ring melted and he managed to shake it off and saved his finger, though he suffered a lot of pain for weeks after. Makes me shudder to think about it, and though I didn't witness the occurence, knowing of it certainly makes me think, when near batteries, etc.
I saw my auto shop teacher in high school be severely burned when his metal banded watch turned red hot. We were working on a 60s model pickup truck, he was holding the ignition switch in his hand, and had his sweaty arm propped on the metal dash, when he turned the key the watch turned bright red in an instant. No permant injury except for a scar arond his wrist. After seeing that I have not worn any metal around electrical work since.
Life is tough, Life is tougher when you are stupid
The other side of it is the electrocution part. Dry skin might just give you a jolt when you contact an energized conductor but if it is a sweaty watch band you are "connected". Add that to being well grounded by sitting on a concrete floor or in the dirt and it is trivial to get to that 150ma or so that instantly fries your heart.
To this day I am a "no metal" guy. No rings, watches or any other metal on my body.
It's not always about the conductivity. A co-worker I had a few years back managed to get his wedding ring caught on a truss while hustling down his ladder. Hung by it for second and nearly stripped the flesh to the bone.
On a side note, I once worked in a house along with a crew of tile guys that had so many piercings in their ears and faces it was hard to look at look at them. If two of them had collided in the hallway it would have shut down all tile production while the entire crew attempted to untangle them from each other.