Environmental Health and Safety

10 CFR 20

Refers to the Code of Federal Regulations, Title 10, Part 20, “Standards for Protection Against Radiation”  (RHB 2364).

17 CRCR

Refers to the California Radiation Control Regulations,  Title 17, Subchapter 4.0. Radiation, sections 30100-30397.

Absorbed Dose

The energy imparted by ionizing radiation per unit mass of irradiated material. The units of absorbed dose are the international unit gray (Gy) or the rad.

Quantity	Name	Symbol	Units	Conversions
Absorbed Dose	gray rad (old unit)	Gy rad	J Kg-1 100 ergs gram-1	1 Gy = 100 rads 1 cGy = 1 rad

Activation

The process of making a material radioactive by bombardment with neutrons, protons, or other nuclear radiation.

Activity

The rate of disintegration per second (dps), minute ( dpm) or decay of radioactive material. The units of activity are the international unit becquerel (Bq) or the curie (Ci).

Quantity	Name	Symbol	Units	Conversions
Activity	becquerel curie (old unit)	Bq Ci	dps 3.7 H 1010Bq	1= Ci = 3.7 X 1010 Bq

millicurie (mCi) = 3.7 H 107 dps

microcurie(μCi) = 3.7 H 104 dps

nanocurie (nCi) = 3.7 H 101 dps

picocurie (pCi) = 3.7 H 10-2 dps

ALARA

Acronym for As Low As Reasonably Achievable. Making every reasonable effort to maintain exposures to radiation as far below the dose limits as practical and consistent with the purpose for which the licensed activity is undertaken, taking into account the state of technology, the economics of improvements in relation to state of technology, the economics of improvements in relation to benefits to the public health and safety, and other societal and socioeconomic considerations.

Analytical X-ray System

A group of components utilizing x rays to determine the elemental composition or to examine the microstructure of materials.

Bioassay

The determination of quantities or concentrations and, in some cases, the locations of radioactive material in the human body, whether by direct measurement (in vivo counting) or by analysis and evaluation of materials excreted or removed from the human body.

Bremsstrahlung

Photons emitted when charged particles decelerate or change direction when passing through matter.

Clean Area

An area within a laboratory that is designated for the consumption and/or storage of food and beverages. A clean area must be clearly separated from any hazardous material use and storage and be specifically approved by the Radiation Safety Office.

Contamination

Deposition of radioactive material in any place where it is not desired.

Controlled Area

A defined work area or laboratory in which occupational exposure of workers to radiation or radioactive material is under the direct control of the university.

Curie

See “Activity.”

Declared Pregnant Worker

A woman who has voluntarily informed her employer, in writing, of her pregnancy and the estimated date of conception for the purpose of monitoring the radiation dose to the fetus.

Deep Dose Equivalent (DDE)

External whole body exposure that is the dose equivalent at a tissue depth of 1 centimeter (1,000 mg/cm2).

DHS

California Department of Health Services, the state’s licensing and regulatory agency.

Diagnostic X-ray System

An X-ray system designed for irradiation of any part of the human or animal body for diagnostic purposes.

Diffraction X-ray System

An X-ray system designed for routine analytical work. The primary beam from the target of the X-ray tube emerges from the machine through a collimator and strikes the sample, which diffracts in a characteristic manner. The diffraction pattern is measured with a photographic film or a radiation detector.

Dose Equivalent

The product of the absorbed dose in tissue, quality factor (i.e., rad H Q = rem) or organ dose weighting factors (i.e., Gy H wT = Sv) and all the necessary modifying factors at the location of interest. The units of dose equivalent are the international unit sievert (Sv) or the rem.

Quantity	Name	Symbol	Units	Conversions
Dose Equivalent	Sievert rem (old unit)	Sv rem	J Kg-1 10-2Sv	100 rem = 1 Sv 1 rem = 1 cSv

Exposure

A measure of the ionization produced in air by X or gamma radiation. The sum of electric charges on all ions of one sign produced in air when all electrons liberated by photons in a volume of air are completely stopped in air, divided by the mass of the air in the volume. The units of exposure in air are the international unit coulomb per kilogram or the roentgen.

Eye Dose Equivalent (LDE)

External exposure of the lens of the eye that is the dose equivalent at a tissue depth of 0.3 centimeters (300 mg/cm2).

Fluoroscopic X-ray System

A system that uses X-ray photons to produce a fluoroscopic image. The system includes an image intensifier with spot film device and linkage between the image receptor and diagnostic source assembly.

Half-life, Radioactive

The time required for a radioactive substance to lose 50‰ of its activity by decay. Each radionuclide has a unique half-life.

High Radiation Area

Any area accessible to individuals that radiation exists at levels such that an individual could receive, in any one hour, a dose equivalent in excess of 100 millirem (1.0 millisievert) at 30 centimeters from the radiation source or from any surface that the radiation penetrates.

Ionizing Radiation

Any electromagnetic or particulate radiation capable of producing ions directly or indirectly in its passage through matter. In general, refers to gamma rays and X-rays, alpha and beta particles, neutrons, protons, high speed electrons and other nuclear particles. Ionizing radiation does not include radiowaves or visible, infrared or ultra-violet light (i.e., non-ionizing radiation).

keV

A thousand electron volts.

LSC

Liquid scintillation counter.

Monitoring

Checking for the presence of sources of radiation under a specific set of conditions. Monitoring includes measuring levels of radiation fields and determining contamination levels. Monitoring is performed both for health protection and for protection of current and future research.

NRC

The U.S. Nuclear Regulatory Commission (NRC) is the primary federal agency charged with regulating the use of byproduct radioactive and special nuclear materials.

Occupational Dose

Occupational dose means the dose received by an employee:

Personnel Dosimetry

Devices that measure the cumulative dose of radiation to an individual. Types of dosimetry include film badges, thermoluminescent dosimeters (TLD), finger rings, and albedo-type for neutron measurements.

Radiation Area

An area accessible to individuals in which radiation exists at such levels that an individual could receive, in any one hour, a dose equivalent to the whole body in excess of 5 mrem (0.05 millisievert) at 30 centimeters from the radiation source or from any surface that the radiation penetrates.

Radiation Producing Machine

Any device capable of producing ionizing radiation when the associated control devices are operated, excluding devices that produce radiation only by use of radioactive materials.

Radiation Safety Committee (RSC)

A committee consisting of SDSU faculty and staff which sets policy regarding use of radioactive material at SDSU consistent with the radioactive materials license.

Radiation Safety Officer (RSO)

The Radiation Safety Officer is responsible for operation of the radiation safety program and assuring that use of ionizing radiation is in conformance with university policies and applicable regulations.

Radiation Use Authorization (RUA)

An authorization issued by the Radiation Safety Committee to conduct specific research using specific radionuclides or ionizing radiation producing machines.

Radioactive Materials

Any material, solid, liquid or gas that emits ionizing radiation spontaneously.

Radiological Safety Index (RSI)

Each RUA is assigned an RSI to determine the radiological risks associated with each approved radioisotope, its quantities and the intended use.

Restricted Area

An area with access limited by radiation to protect individuals from undue risk from exposure to radiation and radioactive material. Any radiation area, high radiation area or airborne radioactivity area shall be considered a restricted area.

Roentgen (R)

A unit of exposure to ionizing radiation. The amount of gamma rays or X-rays required to produce ions carrying 1 electrostatic unit of electrical charge in 1 cubic centimeter of dry air under standard conditions. See “Exposure.”

Roentgen Equivalent Man (rem)

The unit used to express human dose equivalence as a result of exposure to ionizing radiation. The relation of the rem to other dose units depends upon the biological effect of the radiation under consideration.

Shall

Used in laws, regulations or directives to express what is mandatory.

Shallow Dose Equivalent (SDE)

External exposure of the skin or an extremity that is the dose equivalent at a tissue depth of 0.007 centimeters (7 mg/cm2) averaged over an area of 1 square centimeter.

Somatic Effects of Radiation

Long-term effects of radiation to exposed individuals, such as cancer, as opposed to genetic effects to the next generation. Somatic effects may also apply to subsequent unexposed generations beyond the first generation.

Source Materials

Uranium or thorium or any combination thereof in any physical or chemical form, or ores, that contain by weight 1/20th of 1‰ (0.05‰) or more of uranium, thorium or any combination thereof.

Special Nuclear Materials

Plutonium, uranium-233, uranium enriched in the isotope 233 or in the isotope 235, or any other material so designated by the Nuclear Regulatory Commission, but not including source material. Any material artificially enriched by any of the foregoing but not including source material.

Survey Meter

Any portable radiation detection instrument designed to determine the presence of radioactive materials and ionizing radiation fields. Survey meters are of two types:

Unrestricted Area

Any area with access neither limited nor contained by the university for the purpose of protecting individuals from exposure to radiation and radioactive materials.

Wipe Test (Sample)

A test (sample) made to determine the presence of removable radioactive contamination on a surface. A piece of soft filter paper is wiped over 100 square centimeters of area surveyed and counted for radioactivity with an appropriate instrument.