 Tiny amounts of 210Po are sometimes used in the laboratory and for teaching purposes — typically of the order of 4 – 40 kBq (0.11 – 1.08 µCi), in the form of sealed sources, with the polonium deposited on a substrate or in a resin or polymer matrix — are often exempt from licensing by the NRC and similar authorities as they are not considered hazardous. Small amounts of 210Po are manufactured for sale to the public in the United States as'needle sources' for laboratory experimentation, and are retailed by scientific supply companies. The polonium is a layer of plating which in turn is plated with a material such as gold, which allows the alpha radiation (used in experiments such as cloud chambers) to pass while preventing the polonium from being released and presenting a toxic hazard. According to United Nuclear, they typically sell between four and eight such sources per year.
