For purposes of transportation, radioactive materials are defined as those materials
which spontaneously emit ionizing radiation and have a specific activity exceeding 70
Becquerel per gram of material (Bq/g), or 0.002 microcurie per gram of material (µCi/g).
Materials with a specific activity lower than 70 Bq/g (0.002µCi/g) and in which the
activity is essentially uniformly distributed are not regulated by DOT or NRC for
purposes of transportation. The limit of 0.002 microcuries per gram of material allows a
distinction between materials of extremely low radioactivity, i.e., “EXEMPT” from
regulation and those which are regulated as radioactive material for purposes of