Answer to Question #7517 Submitted to "Ask the Experts"
Category: Radiation Workers
The following question was answered by an expert in the appropriate field:
Thank you for your question. Although I don't know exactly what your employer uses as far as radioactive materials go, there are some general things I can share with you about a lab environment.
Regulations require postings to alert people who might enter a room or a lab that radioactive materials are present in the room. They also require that anything in the room that is radioactive be labeled as such.
So when you walk into such a posted area, take a broad look around to see what is in the lab that is radioactive. It might be that you see no labeled items—that just means the lab staff have them secured in a cupboard or in the refrigerator/freezer. Or you might see some lab equipment or samples that have a radioactive material sticker on them—that is the source of the radioactive material. As long as you do not touch or move those items, they are of no hazard to you. Most postings simply say "Caution, radioactive material." That means there is something in the room that is radioactive (and it should be labeled as such). Some postings say "Caution, radiation area." This means that if you are close to the source of radiation (which is labeled), you might receive some radiation exposure from it. You usually need to be within a couple of feet of the source to get exposed. The exposure is required to be low or nothing—otherwise you wouldn't be able to go into the area.
Certified Medical Health Physicist