I have seen 5000 primers shipped FedEx Ground with no HazMat fee paid. I personnally believe it is just a way for the carrier to make a bigger profit. I know that there is a Federal regulation regarding HazMat but I think that the carriers are using it as a way to line their pockets with the smaller shipments. Kind of like the Fuel Surcharge that started getting tacked onto all freight shipments the last few years. Shipping costs have gone up to cover increased costs but the fuel surcharge is still being added to each shipment.