Which method is NOT used to control employee exposure to radiation?

Increasing exposure time is not a method used to control employee exposure to radiation because prolonged exposure can increase the risk of harmful effects. In radiation safety, the goal is to minimize exposure to ensure worker safety. This is accomplished through various methods, such as using shielding materials that absorb or block radiation, maintaining distance from the source of radiation to reduce exposure levels, and minimizing the time spent in an area where radiation is present. Therefore, the correct answer emphasizes that extending exposure time is counterproductive to radiation safety practices.