If an area survey reveals an ambient radiation level of 7 mRem/hr, what sign would be most appropriate to display on the door?

In a radiation safety context, the ambient radiation level is crucial for determining the appropriate signage. An ambient radiation level of 7 mRem/hr indicates a potentially hazardous exposure level that is above natural background levels but does not reach the threshold for classification as a high radiation area.

The key distinction here lies in the definitions of radiation areas. A "Caution: Radiation Area" sign is warranted for locations where the radiation level is above 5 mRem/hr but below 100 mRem/hr in any one hour at 30 centimeters from the source. This signifies that while there is an observable radiation presence, it does not pose an immediate, high risk to personnel entering the area, provided they are aware and follow safety protocols.

In contrast, signage indicating “Caution: High Radiation Area” is reserved for environments where the radiation exceeds 100 mRem/hr, which reflects a higher risk classification. Furthermore, “Grave Danger: Very High Radiation Area” is specified for areas where exposure exceeds 500 rads in an hour, which is excessively dangerous.

Thus, displaying “Caution: Radiation Area” is the most appropriate choice because the 7 mRem/hr level fits neatly within the parameters for this classification, effectively communicating the necessary precautions to anyone