Injection of a radioactive tracer into a hydrocarbon reservoir at high pressure entails handling of materials with properties that are unfamiliar to most laypersons. As radioactive material in quantities used for injections is potentially dangerous, it is important that it be treated properly. In an injection project, safety considerations should have already been taken into account when the tracer is selected and the quantities fixed. During transport and storage at the well head site, the safety aspect should be borne in mind and safety precautions should be taken according to international rules and regulations.