WS2812B LED-strips are ran at 5V, and can consume up to 60mA per LED. This can quickly add up to a few amperes.
Would I receive a chock if I'd touch the connections between each LED while the strip is powered up? I'd guess so, since the current flows between the points -- however I've seen videos of people touching the strip while powered up.
Is it safe to touch the connection points while the strip is powered up?
When your skin is sufficiently wet and clear of any oil or dirt, in best situation its resistance is about 3 K Ohm . When your supply is 5volt , assume you touch directly power pins. Current through your body will be :
I = V / R
I = 5.0 / 3K = 1.67 mA
If we refer to Wiki- Electricity Shock we can determine how much current in how much time cause damage to body.
As you see in case of this current you are always in green part of diagram.
If you touch your tongue, it's resistance will be hundred of ohms. then it's current will be tens of mA. According to this figure if you hold it for more than a second, it will cause you an AS-3 kind of damage, that it's not so serious indeed.
---Edited : According to our discussion in comments I prefer illustrate the Skin model here :
This is Anatomy of skin :
and it's equivalent circuit for this :
According to McAdams , there have been several observations of regional differences of skin impedance in the low-frequency range, which is dominated by Re. Therefore, variations of skin impedance between sites and subjects tend to be due to large variations of Re. Reference
Then as illustrated in this article too, skin resistance has imaginary and real part that in a DC situation only real part will be considered. In This situations skin resistance will vary depending on lots of conditions but at last it will vary from 100K to 500 Ohm in different situations for a normal skin without dirt.
Short answer: it's fine to touch them.
Longer answer:
Roughtly speaking the current through the body depends on three things. The open circuit voltage of the power supply. The source impedance of the power supply and the impedance of the human body.
The impedance of the human body varies a lot depending on contact area, presense of moisture on the skin etc and this makes it difficult to have hard and fast rules on what is safe but the general rule of thumb is that 50V is about the point where you need to start seriously worrying about electric shock risk. 5V is an order of magnitude lower than that.
A lot of people seem to think that high current supplies are more of a shock risk than low current ones. This is true if we are talking about extremely low current supplies but there is going to be negligable difference in tissue current between touching a 5V 100ma supply and a 5V 100A supply. In both cases the source impedance of the supply will be negligable in comparision to the impedance of the body.
Having said that while high current 5V supplies aren't a shock risk under normal conditions they can be a fire and burn risk. IIRC people have had serious burns when jewlery has shorted out high current supplies. If you are deploying large numbers of these LEDs I would suggest splitting their power supply into groups with each group fused at no more than a few amps.
