How bad is this soldering station from ESD perspective?

I found this cheap soldering station called OLED T12, which might be good for my current purposes (I'd like to solder cheap SMDs). According to the images 4 wires run from the station to the iron and the green wire is the ground. So I guess the tip is grounded on this station, which might be a slight ESD protection compared to for example the TS100, which - as far as I can tell - is not grounded. I found a similar Aiyima T12 station, which is AC, but looks almost the same as the first I mentioned and has 5 wires. I checked a few Solomon products too. The ESD safe irons and stations (triple the price compared to OLED T12) are always black and have 5 wires, while the non ESD safe products have only 4 wires and they are not black.

I'd like to know why the Solomon can solve this only with 5 wires, while the OLED T12 has only 4 wires and the tip appears to be grounded on it? I am pretty sure the OLED T12 is inferior to any ESD safe station, but I'd like to know whether it is any better than the TS100 from ESD perspective because of the grounding?

Answer

The differences between an ESD safe station, and one that isn't claiming to be, go well beyond just the tip being grounded.

The entire exterior of an ESD safe station should be made of static dissipative material with a path to ground. This includes the hand grip, wire insulation, and control/power unit. This ensures that the station will not introduce any ESD risk even if it's sitting on the ESD mat or the iron's power cable brushes across your components as you work.

The increased material and engineering costs to make the whole package ESD safe is where you get to cost difference (give or take some extra price gouging for industries that must be ESD certified and people that are just willing to pay away their anxieties).

In terms of practical ESD safety for your average hobbyist, this is probably overkill. The tip is the only thing that should be making contact with your components, so as long as that's grounded and you take all other practical precautions you will be fine. Use an ESD mat and wrist strap. Try not to let the hand grip or cable rub against your components. Should be no functional difference as long as you're careful.