Convert kilogray [kGy] to millirad [mrd] Online | Free radiation-absorbed-dose Converter

Kilogray [kGy]: An Ultra-High Dose of Radiation

The kilogray (kGy) is a unit of absorbed radiation dose equal to 1,000 grays (Gy). This represents an extremely large amount of energy—1,000 joules of ionizing radiation absorbed per kilogram of matter. Such doses are far beyond those encountered in medical or environmental settings and are typically relevant only in specialized industrial and scientific applications.

Kilograys are commonly used in radiation processing, such as:

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  Sterilization of medical supplies and pharmaceuticals, where very high doses ensure the destruction of bacteria, viruses, and other microorganisms.

  
  
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  Food irradiation to increase shelf life and reduce pathogens.

  
  
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  Material modification, including polymer cross-linking and degradation studies.

  
  
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  Radiation hardness testing for electronics and materials exposed to extreme environments, like space or nuclear reactors.

  
  

In biology and medicine, doses in the kilogray range would be lethal to all known life forms. Therefore, the kGy is never used to describe radiation exposure to humans or animals.

The kilogray highlights the versatility of the gray as a unit of radiation dose, scaling from tiny fractions used in diagnostics to massive doses used in industrial processes, reflecting the broad spectrum of radiation’s applications across science and technology.

Millirad [mrd]: A Subunit of Radiation Absorbed Dose

The millirad (mrd) is a unit of absorbed radiation dose equal to one-thousandth of a rad. The rad (radiation absorbed dose) is an older, non-SI unit that was commonly used before the gray (Gy) became the standard.

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  1 rad = 0.01 gray (Gy)

  
  
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  Therefore, 1 millirad = 0.001 rad = 0.00001 Gy (10⁻⁵ Gy)

  
  

The millirad was used to measure the amount of energy absorbed from ionizing radiation per unit mass, primarily in radiation protection and medical contexts.

Though the rad and its subunits like the millirad have largely been replaced by the gray and its subunits (milligray, microgray, etc.), they may still be encountered in older literature or certain regions.

In summary, the millirad is a very small dose unit equal to one-thousandth of a rad, useful historically for quantifying low-level radiation exposures before the universal adoption of the gray.