Electric oil baseboard heaters are just as safe as the standard hardwired baseboard heater. However, with both types, it is necessary to leave a foot of space between the heaters and anything flammable. Outlets within a foot of the heaters are no longer usable.
The warmth of the heaters compromises the wires of items plugged into outlets within a foot of the heater, whether it is oil-filled or hardwired. Oil-filled electric baseboard heaters do offer a couple of advantages. They heat up and cool down more slowly, making temperature changes less uncomfortable. This also keeps the unit from turning on again too quickly, potentially saving electricity over time.