What does "rad" represent in radiation safety?

The term "rad" stands for "radiation absorbed dose" and is indeed recognized as the basic unit of absorbed dose in radiation safety. It measures the amount of radiation energy absorbed by a specific mass of material, typically biological tissue. One rad is equivalent to an energy absorption of 0.01 joules per kilogram of tissue.

In the context of radiation safety, understanding the absorbed dose is critical because it helps to quantify the potential biological effects of radiation on humans and other organisms. The unit has now largely been replaced by the gray (Gy), with one gray being equal to 100 rads. However, the rad is still encountered frequently in discussions about historical data and in certain applications within the medical and safety fields. This foundational concept is crucial for professionals working with radiation to ensure proper safety measures are in place based on the levels of exposure.