Missouri Code of State Regulations › Title 19 - DEPARTMENT OF HEALTH AND SENIOR SERVICES › Division 20 - Division of Community and Public Health › Chapter 10 - Protection Against Ionizing Radiation › Section 19 CSR 20-10.010 - Definitions Relating to Ionizing Radiation

Current through Register Vol. 49, No. 14, July 15, 2024
PURPOSE: This rule defines technical terms which are
				  used throughout this chapter.
PUBLISHER'S NOTE: The secretary of state has
				  determined that the publication of the entire text of the material which is
				  incorporated by reference as a portion of this rule would be unduly cumbersome
				  or expensive. Therefore, the material which is so incorporated is on file with
				  the agency who filed this rule, and with the Office of the Secretary of State.
				  Any interested person may view this material at either agency's headquarters or
				  the same will be made available at the Office of the Secretary of State at a
				  cost not to exceed actual cost of copy reproduction. The entire text of the
				  rule is printed here. This note refers only to the incorporated by reference
				  material.
(1) Absorbed dose
				of any ionizing radiation is the energy imparted to matter by ionizing
				particles per unit mass of irradiated material at the place of interest. The
				unit of absorbed dose is the rad.
(2) Aluminum equivalent is the thickness of
				aluminum affording the same attenuation, under specified conditions, as the
				material in question.
(3)
				Controlled area is an area in which the occupational exposure of personnel to
				radiation or to radioactive material is under the supervision of an individual
				in charge of radiation protection. (This means that a controlled area is one
				that requires control of access, occupancy and working conditions for radiation
				protection purposes.)
(4) Dead-man
				switch is a switch so constructed that a circuit-closing contact can only be
				maintained by continuous pressure by the operator.
(5) Department is the Missouri Department of
				Health.
(6) Dose, unless otherwise
				indicated, as used in these rules, means rem dose.
(7) Effective half-life (T), in days, is-
T=(Tb) x (Tr) /
				  (Tb) + (Tr)
where Tb= biological half-life in
				  days; and
where Tr= physical half-life in
				  days.
(8) Excessive
				radiation dose is a dose of radiation in excess of the maximum permissible dose
				(19 CSR
				20-10.040 ).
(9) Individual is any human being.
(10) Installation is a place containing one
				(1) or more sources of radiation.
(11) Lead equivalent is the thickness of lead
				affording the same attenuation, under specified conditions, as the material in
				question.
(12) Maximum permissible
				accumulated dose (MPAD) is the dose of radiation which, if accumulated during
				the lifetime of the individual, is not expected to cause observable bodily
				injury.
(13) Maximum permissible
				dose (MPD) is the maximum rem dose that the body of an individual or specific
				parts of the body shall be permitted to receive in a stated period of
				time.
(14) Person is any
				individual, partnership, association, corporation, firm, trust, estate, public
				or private institution, group, agency, political subdivision of this state and
				any legal successor, representative, agent or agency of them.
(15) Personnel monitoring is the
				determination of the radiation dose received by an individual during the
				specified period.
(16) Protective
				barrier is a barrier of attenuating materials used to reduce radiation
				exposure.
(17) Qualified expert is
				an individual fitted by training and experience to perform dependable radiation
				surveys, to oversee radiation monitoring and to estimate the degree of
				radiation hazard. If the ability of a qualified expert is questioned, the
				department shall be the judge of his/her qualifications, in regard to which it
				may consider the testimony of other persons whom it deems expert.
(18) Rad is the unit of absorbed dose and is
				equal to one hundred (100) ergs per gram. It is a measure of the energy
				imparted to matter by ionizing particles per unit mass of irradiated material
				at the place of interest.
(19)
				Radiation is gamma rays and X-rays, alpha and beta particles, high-speed
				electrons, neutrons, protons, other nuclear particles and any other ionizing
				radiation, but not sound or radio waves or visible, infrared or ultraviolet
				light.
(20) Radiation hazard is any
				condition that might result in the exposure of individuals to excessive
				radiation dose.
(21) Radiation
				machine is any device that produces radiation when in operation.
(22) Radioactive material is any material,
				solid, liquid or gas, that emits radiation spontaneously.
(23) Relative biological effectiveness (RBE)
				is a numerical factor which is used to compare the effectiveness of absorbed
				dose of radiation delivered in different ways. The standard of comparison is
				X-ray or gamma radiation having a linear energy transfer in water of three (3)
				kev per micron. A list of RBE values of various kinds of radiation is given in
				Table 1,
				19 CSR
				20-10.110.
(24) Rem is equal to the absorbed dose in
				rads multiplied by the appropriate RBE.
(25) Roentgen is a unit of exposure dose of
				X-ray or gamma radiation such that the associated corpuscular emission per
				0.001293 gram of air produces, in air, ions carrying one (1) esu of quantity of
				electricity.
(26) Sealed source is
				a quantity of radioactive material so enclosed as to prevent the escape of any
				radioactive material.
(27) Source
				(of radiation) is a radiation machine or a quantity of radioactive
				materials.
(28) Survey is the
				evaluation of actual or potential radiation or contamination hazards by or
				under the supervision of a qualified expert.
(29) X-ray tube housing protective
				diagnostic-type is one that reduces the leakage radiation to a maximum of 0.10
				roentgen in one (1) hour at a distance of one (1) meter from the tube target
				when the X-ray tube is operating at its maximum current and voltage.
(30) X-ray tube housing protective
				therapeutic-type is a tube housing so constructed that the leakage radiation at
				a distance of one (1) meter from the target cannot exceed the rate of one (1)
				roentgen per hour and at a distance of five centimeters (5 cm) from any point
				on the surface of the housing accessible to the patient cannot exceed the rate
				of thirty (30) roentgens per hour when the tube is operated at its maximum
				current and voltage.
(31) Useful
				beam is that part of radiation which passes through the window, aperture, cone
				or collimating device of the tube housing.
(32) User is a person having administrative
				control over one (1) or more sources.
(33) Other scientific and technical terms not
				specifically defined in this rule shall be used in accordance with the
				definitions in recommendations of the National Committee on Radiation
				Protection and Measurements as published in
Handbooks of the National
				Bureau of Standards
or the American Standard Association's
Glossary of Terms in Nuclear Science and Technology
, with
				preference being in the order given.
*Original authority: 192.420, RSMo
					 1963.