Removing the fuse from the fused spur, only isolates the Live conductor, which is not a good idea, the fused spur, may have been inadvertently been connected up incorrectly ie reversed polarity, securing the fuse holder is stupid as anyone working with you could easily cut the tie wrap, rendering your companies idea of safe isolation useless, There are kits out there that allow you to isolate the Circuit Breaker (CBs) covering the circuit the fused spur is connected to, and these can be bought from many of the Electrical wholesaler that litter the industrial estates.