In these Regulations, unless the context otherwise requires-
"irradiating apparatus" (輻照儀器) means any apparatus which-
(a) is intended to produce or emit ionizing radiation; or
(b) is capable of producing or emitting ionizing radiation at a dose rate exceeding 5 μSv per hour at a distance of 5 cm from any accessible point of the surface of the apparatus;
"radioactive substance" (放射性物質) means any substance which consists of or contains any radioactive chemical element whether natural or artificial and whose specific activity exceeds 75 bequerels of parent radioactive chemical element per gram of substance.