Yttrium, Radioactive

Threshold Limit Values

The TLV Physical Agents Committee accepts the occupational exposure guidance of the International Commission on Radiological Protection (ICRP). ... ICRP Guidelines for Exposure to Ionizing Radiation: Effective Dose (a) in any single year, 50 mSv, (b) averaged over 5 years, 20 mSv per year. Annual Equivalent Dose to: (a) lens of the eye, 150 mSv, (b) skin, 500 mSv, (c) hands and feet, 500 mSv. Embryo-Fetus exposures once the pregnancy is known - monthly equivalent dose 0.5 mSv - dose to the surface of women's abdomen (lower trunk) 2 mSv for the remainder of the pregnancy - intake of radionuclide one twentieth of Annual Limit on Intake (ALI). /Ionizing radiation/
The TLV Physical Agents Committee accepts the occupational exposure guidance of the International Commission on Radiological Protection (ICRP). Ionizing radiation includes particulate radiation (e.g., alpha particles and beta particles emitted from radioactive materials, and neutrons from nuclear reactors and accelerators) and electromagnetic radiation (e.g., gamma rays emitted from radioactive materials and x-rays from electron accelerators and x-ray machines) with energy greater than 12.4 electron-volts (eV) ... The guiding principle of radiation protection is to avoid all unnecessary exposures. ICRP has established principles of radiological protection. These are (1) the justification of a work practice: No work practice involving exposure to ionizing radiation should be adopted unless it produces sufficient benefit to the exposed individuals or the society to offset the detriment it causes. (2) The optimization of a work practice: All radiation exposures must be kept as low as reasonably achievable (ALARA), economic and social factors being taken into account. (3) The individual dose limits: The radiation dose from all relevant sources should not exceed the /ICRP/ prescribed dose limits. /Ionizing radiation/
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