keep in mind, you can unplug something like a sump pump from a single receptacle and plug in what ever you want. That kind of defeats the "no gfi needed" train of thinking. Second if the refridgerator, sump pump, washer, etc, is tripping a gfi it's the appliance, most likely the motor in it, that has failed. One of the members here posted, a couple of years ago, that he would use a megger and check appliances like refers, that had tripped GFCI's and the result was ALL of them failed. It was not the gfi that was the problem but the motors had gone bad, not enough to fail but enough that a gfi would detect it.
I should add, as child I was shocked three times, mildly, that all would have been prevented if gfic proection had been required back then. The first was an exterior extention cord that was defective, ouch. The second was a pool light that was bad, when I put my foot near it i got a numbing "tingle" in my leg, that could have ended very badly for me in so many ways. The third was a laundry room outlet, when I touched my one hand to the grounded washer and the other to a bad iron, it was a right hand to left hand shock that hurt so bad my ears were ringing. So my question would is simple, Why not put on a GFCI recepticle? My supply house charges me $8.00 each for a Leviton GFCI receptacle.