These radiation safety requirements were prepared and approved by the Centers for Disease Control and Prevention (CDC) Radiation Safety Committee with the guidance of the CDC Radiation Safety Officer for CDC laboratory scientists and technical staff who use radioactive material licensed by the Nuclear Regulatory Commission. Applicable regulations are incorporated in this manual, along with procedures for handling radioactive material. The manual is a practical reference, but users must also have technical knowledge of radiation and some experience in handling radioactive materials. The safety requirements provided in this manual form the basic program. The Office of Health and Safety provides radioisotope users with required safety procedures on the use of radioactive materials in the laboratory setting and on general laboratory practices. The Radiation Safety Manual is one chapter of the CDC/ATSDR Occupational Health and Safety Manual.