What label is used for packages with a radiation level of 40 mrem/hr on the surface?

The correct label for packages with a radiation level of 40 mrem/hr on the surface is "Radioactive II."

In the classification system for radioactive materials, different labels are assigned based on the level of radiation exposure. "Radioactive I" is designated for materials that produce a low radiation level (up to 0.5 mrem/hr), which is considered safe for most conditions. In contrast, "Radioactive II" covers a range where surface radiation exposure is between 0.5 mrem/hr and 50 mrem/hr, making it applicable for packages with a surface radiation level of 40 mrem/hr. This means that while the exposure is higher than “Radioactive I,” it is still within a safety threshold established for transport under regulated conditions.

"Radioactive III" applies to materials with even higher levels of radiation exposure, exceeding 50 mrem/hr, which would not fit for a 40 mrem/hr reading. "Dangerous Goods" is a broader term that encompasses a wide variety of hazardous materials, not specifically limited to radiological hazards, and does not identify the specific levels of radiation present in the package. Thus, the labeling accurately communicates the potential radiation hazards associated with the material being transported.