Electrocution risk - serious.
Electrocuted: I bought one of the Smart Air Filters (Sqair) for the home, with the additional charcoal filter. I have been electrocuted numerous times by this filter. What happens is: when you accidentally disconnect the power cord from the power outlet (life happens: you trip over the cord, you forget as you clean around it, etc.) before you manually turn off the filter, and your body comes anywhere near the end of the power cord (you don't have to touch it) you get a very painful shock, which numbed my arm for several hours the last time it happened. This has happened several times over the last year (each time the shock was worse) and it is not normal behavior of any electrical appliance I have ever dealt with in my life. I can unplug any appliance, computer, or phone without turning it off an never get shocked by the power cord. Terriblly unsafe engineering and design. By the way, the charcoal filter is a joke but they at least admit as much in their promotional material. Furthermore, their power consumption ratings are dishonest as this thing hogs power on the higher settings, far in excess of many other models but they only compare to models that are even worse than theirs to make it seem like their filters' power consumption is good. Finally, it is very loud unless it is on the lowest fan setting. One of the loudest air filters I have ever had of this small size.