HAR §11-45-13. Units of exposure and dose

(a) As used in these rules, the unit of exposure is the coulomb per kilogram (C/kg). One roentgen is equal to 2.58 x 10-4 coulomb per kilogram of air. (b) As used in these rules, the units of dose are: (1) Gray (Gy) is the SI unit of absorbed dose. One gray is equal to an absorbed dose of one joule per kilogram (one hundred rads). (2) Rad is the special unit of absorbed dose. One rad is equal to an absorbed dose of one hundred erg per gram or 0.01 joule per kilogram (0.01 gray). (3) Rem is the special unit of any of the quantities expressed as dose equivalent. The dose equivalent in rem is equal to the absorbed dose in rad multiplied by the quality factor (one rem = 0.01 sievert). (4) Sievert is the SI unit of any of the quantities expressed as dose equivalent. The dose equivalent in sievert is equal to the absorbed dose in gray multiplied by the quality factor (one sievert = one hundred rems). (c) As used in these rules, the quality factors for converting absorbed dose to dose equivalent are shown in Appendix A of this subchapter. (d) If it is more convenient to measure the neutron fluence rate than to determine the neutron dose equivalent rate in sievert per hour or rem per hour, as provided in subsection (c), one rem (0.01 sievert) of neutron radiation of unknown energies may, for purposes of these rules, be assumed to result from a total fluence of twenty five million neutrons per square centimeter incident upon the body. If sufficient information exists to estimate the approximate energy distribution of the neutrons, the licensee may use the fluence rate per unit dose equivalent or the appropriate Q value from Appendix B of this subchapter to convert a measured tissue dose in gray or rad to dose equivalent in sievert or rem. (e) The exhibits at the end of chapter 11-45 entitled "Appendix A of Subchapter 1, Quality Factors and Absorbed Dose Equivalencies (2/2/93)" and "Appendix B of Subchapter 1, Mean Quality Factors, Q, and Fluence Per Unit Dose Equivalent for Monoenergetic Neutrons (2/2/93)" are made a part of this section. [Eff 11/12/99] (Auth: HRS §§321-10, 321-11, 321-71) (Imp: HRS §§321-1, 321-11(21), 321-71) §11-45-18 45-35