Section 120.923 - Subsurface Tracer Studies(A) The licensee shall require all personnel handling radioactive tracer material to use protective gloves and, if required by the license, other appropriate protective clothing and equipment. The licensee shall take precautions to avoid ingestion or inhalation of radioactive tracer material and to avoid contamination of the field stations and temporary jobsites.(B) A licensee may not knowingly inject radioactive material into fresh water aquifers without prior written authorization from the Agency.