Just like the old days of wheat mills, when the danger of explosions from igniting wheat dust by fire or spark using grinding wheel stones was great, the same holds true for dust collectors today. Although danger of explosions from metal debris such as nails or screws coming in contact with the impeller is rare, it is always wise to err on the side of caution. One good way to avoid this risk is to select a single stage collector with either plastic or aluminum. And of course, always use good sense when cleaning up work benches and floors.