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Subpart 38.3


(a) As used in this Part (rule), these terms have the definitions set forth below:

(1) "A1" means the maximum activity of special form radioactive material permitted in a Type A package. "A2" means the maximum activity of radioactive material, other than special form radioactive material, permitted in a Type A package. These values are either listed or may be derived in accordance with the procedure prescribed in Appendix A-12 of section 38.41 of this Part (rule).

(2) "Absorbed dose" means the energy imparted by ionizing radiation per unit mass of irradiated material. The units of absorbed dose are the gray (Gy) and the rad.

(3) "Accelerator-produced material" means any material made radioactive by a particle accelerator.

(4) "Activity" means the rate of disintegration or transformation or decay of radioactive material. The units of activity are the becquerel (Bq) and the curie (Ci).

(5) "Adult" means an individual 18 years, or more, of age.

(6) Agreement state" means any State with which the United States Nuclear Regulatory Commission or the United States Atomic Energy Commission has entered into an effective agreement under section 274b of the Atomic Energy Act of 1954, as amended (73 Stat. 689).

(7) "Airborne radioactive material" means any radioactive material dispersed in the air in the form of dust, fumes, particulates, mists, vapors, or gases.

(8) "Airborne radioactivity" area means a room, enclosure, or area in which airborne radioactive materials exist in concentrations:

(i) in excess of the derived air concentrations (DACs) specified in Appendix A-13 of section 38.41 of this Part (rule); or

(ii) to such a degree that an individual present in the area without respiratory protective equipment could exceed, during the hours an individual is present in a week, an intake of 0.6 percent of the annual limit on intake (ALI) or 12 DAC-hours.

 (9) "Annual limit on intake (ALI)" means the derived limit for the amount of radioactive material taken into the body of an adult worker by inhalation or ingestion in a year. The derived limit for a given radionuclide is the lesser of the following: the intake by reference man in a year that would result in a committed effective dose equivalent of 0.05 Sv (5 rem) or a committed dose equivalent to any individual organ or tissue of 0.5 Sv (50 rem). ALI values for intake by ingestion and inhalation of selected radionuclides are given in Appendix A-13 of section 38.41 of this Part (rule).

(10) "As low as is reasonably achievable (ALARA)" means making every reasonable effort to maintain exposures to radiation as far below the dose limits in these regulations as is practical, consistent with the purpose for which the licensed or registered 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, and in relation to utilization of sources of radiation in the public interest.

(11) "Background radiation" means radiation from cosmic sources, naturally occurring radioactive materials in the environment including radon (except as a decay product of regulated sources or special nuclear material), and global fallout as it exists in the environment from the testing of nuclear explosive devices. Background radiation does not include radiation from radioactive materials regulated by the department.

(12) "Becquerel (Bq)" means the SI unit of activity. One becquerel is equal to onedisintegration or transformation per second (s-1).

(13) "Bioassay" means the determination of kinds, 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. For purposes of these regulations, radiobioassay is an equivalent term.

(14) "Byproduct material" means:

(i) any radioactive material, except special nuclear material, yielded in or made radioactive by exposure to the radiation incident to the process of producing or utilizing special nuclear material; and

(ii) the tailings or wastes produced by the extraction or concentration of uranium orthorium from ore processed primarily for its source material content, including discrete surface wastes resulting from uranium or thorium solution extraction processes. Underground ore bodies depleted by these solution extraction operations do not constitute byproduct material within this definition.

(15) "Calendar quarter" means not less than 12 consecutive weeks nor more than 14 consecutive weeks. The first calendar quarter of each year shall begin in January and subsequent calendar quarters shall be so arranged such that no day is included in more than one calendar quarter, and no day in any one year is omitted from inclusion within a calendar quarter. No licensee or registrant shall change the method used to determine calendar quarters for purposes of these regulations except at the beginning of a calendar year.

(16) "Calibration" means the determination of:

(i) the response or reading of an instrument relative to a series of known radiation values over the range of the instrument; or

(ii) the strength of a source of radiation relative to a standard.

(17) "CFR" means Code of Federal Regulations.

(18) "Class" means a classification scheme for inhaled materials according to its rate of clearance from the pulmonary region of the lung. Materials are classified as D, W, or Y, which applies to a range of clearance half-times: for Class D, Days, of less than 10 days; for Class W, Weeks, from 10 to 100 days; and for Class Y, Years, of greater than 100 days. For purposes of these regulations, "lung class" and "inhalation class" are equivalent terms.

(19) "Collective dose" means the sum of the individual doses received in a given period of time by a specified population from exposure to a specified source of radiation.

(20) "Commissioner" means the Commissioner of Labor of the State of New York.

(21)  "Committed dose equivalent (HT,50)" means the dose equivalent to organs or tissues of reference (T) that will be received from an intake of radioactive material by an individual during the 50-year period following the intake.

(22)  "Committed effective dose equivalent (HE,50)" is the sum of the products of the weighting factors applicable to each of the body organs or tissues that are irradiated and the committed dose equivalent to each of these organs or tissues (HE,50 =EWTHT,50).

(23) "Constraint" (does constraint) means a value above which, specified licensee actions are required.

(24) "Controlled area" means any area to which access is controlled for the purpose of protecting individuals from exposure to radiation and radioactive material, but shall not mean any area used as residential quarters. Controlled area as used in this Part is synonymous with restricted area.

(25) "Curie" means a unit of activity. One curie (Ci) is that quantity of radioactive material which disintegrates or decays at the rate of 3.7 x 1010  transformations per second

(26) "Declared pregnant woman" means a woman who has voluntarily informed her employer, in writing, of her pregnancy. The written declaration shall include an estimated date of conception or the estimated age of the embryo/fetus in days or weeks as of the date of declaration.

(27) "Decommission" means to remove (as an installation) safely from service and reduce residual radioactivity to a level that permits release of the property for unrestricted use and termination of license.

(28)  "Deep dose equivalent" (Hd), which applies to external whole body exposure, means the dose equivalent at a tissue depth of one centimeter (1000 mg/cm2  ).

(29) "Department" means the New York State Department of Labor and shall include its duly authorized representatives.

(30) "Depleted uranium" means the source material uranium in which the isotope uranium-235 is less than 0.711 weight percent of the total uranium present.

(31) "Derived air concentration (DAC)" means the concentration of a given radionuclide in air which, if breathed by reference man for a working year of 2,000 hours under conditions of light work, results in an intake of one ALI. For purposes of these regulations, the condition of light work is an inhalation rate of 1.2 cubic meters of air per hour for 2,000 hours in a year. DAC values are given in Appendix A-13 of section 38.41 of this Part (rule).

(32) "Derived air concentration-hour (DAC-hour)" means the product of the concentration of radioactive material in air (expressed as a fraction or multiple of the derived air concentration for each radionuclide) and the time of exposure to that radio nuclide, in hours. A licensee or registrant may take 2,000 DAC-hours to represent 1 ALI, equivalent to a committed effective dose equivalent of 0.05 Sv (5 rem).

(33) "Dose or radiation dose" is a generic term that means absorbed dose, dose equivalent, effective dose equivalent, committed dose equivalent, committed effective dose equivalent, or total effective dose equivalent.

(34)  "Dose equivalent (HT)" means the product of the absorbed dose in tissue, quality factor, and all other necessary modifying factors at the location of interest. The units of dose equivalent are the sievert (Sv) and rem.

(35) "Dosimetry processor" means an individual or organization that processes and evaluates individual monitoring devices in order to determine the radiation dose delivered to the monitoring devices.

(36)  " Effective dose equivalent (HE)" means the sum of the products of the dose equivalent to each organ or tissue (HT) and the weighting factor (WT ) applicable to each of the body organs or tissues that are irradiated (HE=EWTHT).

(37) "Embryo/fetus" means the developing human organism from conception until the timeof birth.

(38) "Entrance or access point" means any location through which an individual could gain access to radiation areas or to radioactive materials. This includes entry or exit portals of sufficient size to permit human entry, irrespective of their intended use.

(39) "Exposure" means either:

(i) being exposed to ionizing radiation or to radioactive material; or

(ii) the quotient of dQ by dm where "dQ" is the absolute value of the total charge of the ions of one sign produced in air when all the electrons (negatrons and positrons) liberated by photons in a volume element of air having mass "dm" are completely stopped in air. The special unit of exposure is the roentgen (R). One roentgen is equal to 2.58 x 10-4  coulomb per kilogram of air.

(40) "External dose" means that portion of the dose equivalent received from any source of radiation outside the body.

(41) "Extremity" means hand, elbow, arm below the elbow, foot, knee, or leg below the knee.

(42) "Eye dose equivalent" means the external dose equivalent to the lens of the eye at a tissue depth of 0.3 centimeter (300 mg/cm2).

(43) "Gray (Gy)" means the SI unit of absorbed dose. One gray is equal to an absorbed dose of 1 joule/kilogram. One gray is equal to 100 rad.

(44) "High radiation area" means any area, accessible to individuals, in which radiation levels could result in an individual receiving a dose equivalent in excess of 1 mSv (0.1 rem) in one hour at 30 centimeters from the radiation source or from any surface that the radiation penetrates.

(45) " Human use" means the internal or external administration of radiation or radio active material to human beings.

(46) "Individual" shall mean any human being.

(47) "Individual monitoring" means the assessment of:

(i) dose equivalent;

(a) by the use of individual monitoring devices; or

(ii) committed effective dose equivalent;

(a) by bioassay; or

(b) by determination of the time-weighted air concentrations to which anindividual has been exposed; that is, DAC-hours.

(48) "Individual monitoring devices" means devices designed to be worn by a single individual for the assessment of dose equivalent. For purposes of these regulations, individual monitoring equipment and personnel monitoring equipment are equivalent terms. Examples of individual monitoring devices are film badges, thermoluminescent dosimeters (TLDs), pocket dosimeters, and personal air sampling devices.

(49) " Interlock" means a device arranged or connected such that the occurrence of an event or condition is required before a second event or condition can occur or continue to occur.

(50) " Internal dose" means that portion of the dose equivalent received from radio active material taken into the body.

(51) "License" means a radioactive material license issued by the commissioner in accordance with the regulations adopted by the commissioner. There are two types of licenses: general and specific. A general license means a license issued pursuant to the terms and conditions of section 38.5 of this Part (rule). General licenses are effective without the filing of an application with, or the issuance of a licensing document by, the commissioner. A specific license shall mean a license evidenced by a licensing document issued by the commissioner to a licensee. A specific license also means a similar license issued by the State Department of Health, the New York City Department of Health, the United States Nuclear Regulatory Commission or any agreement state. Unless otherwise specified, the type of license referred to in this Part will be a specific license.

(52) "Licensed material" means radioactive material received, possessed, used, transferred or disposed of under a general or specific license issued by the commissioner.

(53) " Licensee" means any person who is licensed by the commissioner in accordance with these regulations or one who possesses any radioactive material which is subject to the licensure requirements of this Part (rule).

(54) "Limits or dose limits" means the permissible upper bounds of radiation doses.

(55) " Lost or missing licensed material" means licensed material whose location is unknown. This definition includes licensed material that has been shipped but has not reached its planned destination and whose location cannot be readily traced in the transportation system. 

(56) " Member of the public" means any individual, except an individual who is performing assigned duties for the licensee or registrant involving exposure to sources of radiation.

(57) "Minor" means an individual less than 18 years of age.

(58) "Monitoring" means the measurement of radiation levels, radioactive material concentrations, surface area concentrations or quantities of radioactive material and the use of the results of these measurements to evaluate potential exposures and doses. For purposes of these regulations, radiation monitoring and radiation protection monitoring are equivalent terms.

(59) "NARM" means any naturally occurring or accelerator-produced radioactive material. It does not include byproduct, source, or special nuclear material.

(60) "Nonstochastic effect" means a health effect, the severity of which varies with the dose and for which a threshold is believed to exist. Radiation-induced cataract formation is an example of a nonstochastic effect. For purposes of these regulations, a deterministic effect is an equivalent term.

(61) "Nuclear Regulatory Commission (NRC)" means the U.S. Nuclear Regulatory Commission or its duly authorized representatives.

(62) "Occupational dose" means the dose received by an individual in the course of employment in which the individual's assigned duties involve exposure to sources of radiation, whether in the possession of the licensee, registrant, or other person. Occupational dose does not include doses received: from background radiation, as a patient from medical practices, from voluntary participation in medical research programs, or as a member of the public.

(63) "Operator" means any person conducting the business or activities carried on within the radiation installation or having by law the administrative control of a radiation source whether as owner, lessee, contractor, or otherwise.

(64) "Package" means the packaging, together with its radioactive contents as presented for transport.

(65) "Particle accelerator" means any machine capable of accelerating electrons, protons,deuterons, or other charged particles in a vacuum and of discharging the resultant particulate or other radiation into a medium with energies usually in excess of one MeV.

(66) "Person" means any individual, corporation, partnership, firm, association, trust, estate, public or private institution, group, agency, political subdivision of this State, any other state or political subdivision or agency thereof, and any legal successor, representative, agent, or agency of the foregoing, but shall not include Federal government agencies.

(67) "Personnel monitoring equipment" (see individual monitoring devices).

(68) "Possess" means to acquire and take responsibility for radiation sources. A licensee or registrant continues to "possess" and be responsible for a radiation source until it is transferred to another licensee or registrant who is authorized to receive the source in accordance with the provisions of this Part, the equivalent reguations of the United States Nuclear Regulatory Commissioner, or the rules of any other state.

(69) "Principal activities" means activities authorized by the license which are essential to achieving the purpose(s) for which the license was issued or amended, excluding storage or disposal of licensed materials and excluding activities incidental to decontamination or decommissioning.

(70) "Protective barrier" means a barrier of radiation absorbing material(s) used to attenuate the useful beam and/or stray radiation to the degree required to assure compliance with sections 38.18 and 38.19 of this Part (rule).

(71) "Public dose" means the dose received by a member of the public from exposure to sources of radiation regulated by this Part (rule). It does not include occupational dose, dose received from background radiation, dose received as a patient from medical practices, or dose from voluntary participation in medical research programs.

(72) "Quality factor (Q)" means the modifying factor, that is used to derive dose equivalent from absorbed dose.

(i) As used in these regulations, the quality factors for converting absorbed dose to dose equivalent are shown in Table 1 of this paragraph.

(ii) 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 Table 1 of this paragraph; 0.01 Sv (1 rem) of neutron radiation of unknown energies may, for purposes of these regulations, be assumed to result from a total fluence of 25 million neutrons per square centimeter incident upon the body. If sufficient information exists to estimate the approximate energy distribution of the neutrons, the licensee or registrant may use the fluence rate per unit dose equivalent or the appropriate Q value from Table 2 of this paragraph to convert a measured tissue dose in gray or rad to dose equivalent in sievert or rem.

(73) Quarter (see calendar quarter).

(74) "Rad" means the special unit of absorbed dose. One rad is equal to an absorbed dose of100 erg/gram or 0.01 joule/kilogram (0.01 gray). One millirad equals 0.001 rad.

(75) " Radiation" means alpha particles, beta particles, gamma rays, X-rays, neutrons, high-speed electrons, high-speed protons, and other particles capable of producing ions. For purposes of these regulations, ionizing radiation is an equivalent term. Radiation, as used in these regulations, does not include non-ionizing radiation, such as radiowaves or microwaves, visible, infrared or ultraviolet light.

(76) "Radiation area" means any area, accessible to individuals, in which radiation levels could result in an individual receiving a dose equivalent in excess of 0.05 mSv (0.005 rem) in one hour at 30 centimeters from the source of radiation or from any surface that the radiation penetrates.

(77) "Radiation equipment" means any equipment or device which can emit radiation by virtue of the application thereto of high voltage.

(78) "Radiation installation" means any place, facility or mobile unit where a radiation source is located or used.

(79) "Radiation safety officer" shall mean an individual who, under the authorization of the operator of a radiation installation, administers a radiation protection program in accordance with section 38.17 of this Part (rule) and who is qualified by training and experience in radiological health to evaluate the radiation hazards of such installation and administer such radiation protection program.

(80) "Radiation source" means any radioactive material or any radiation equipment.

(81) "Radioactive material" means any solid, liquid, or gas which emits radiation spontaneously.

(82) "Radioactivity" means the transformation of unstable atomic nuclei by the emission of radiation.

(83) "Reference" man means a hypothetical aggregation of human physical and physiological characteristics determined by international consensus. These characteristics may be used to standardize results of experiments and to relate biological insult to a common base.

(84) "Registrant" means any person who is registered with the commissioner or is legally obligated to register with the commissioner pursuant to these regulations.

(85) "Registration" means registration with the commissioner in accordance with these regulations.

(86) "Rem" means 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 (1 rem = 0.01 sievert).

(87) "Respiratory protective equipment" means an apparatus, such as a respirator, used to reduce an individual's intake of airborne radioactive material.

(88) "Restricted area" means any area to which access is controlled for the purpose of protecting individuals from exposure to radiation and radioactive material, but shall not mean any area used as residential quarters. Restricted area as used in this Part (rule) is synonymous with controlled area.

(89) "Roentgen" means the special unit of exposure. One roentgen (R) equals 2.58 x 10-4 coulombs/kilogram of air (see exposure).

(90) "Sanitary sewerage" means a system of public sewers for carrying off waste and refuse, but excluding sewage treatment facilities, septic tanks, and leach fields owned or operated by the licensee or registrant.

(91) "Scattered radiation" means radiation whose direction has been altered during passage through matter. (It may have been modified also by a decrease in energy.)

(92) "Sealed source" means radioactive material that is permanently bonded or fixed in a capsule or matrix designed to prevent release and dispersal of the radioactive material under the most severe conditions which are likely to be encountered in normal use and handling.

(93) "Shallow dose equivalent" (Hs), which applies to the external exposure of the skin oran extremity, means the dose equivalent at a tissue depth of 0.007 centimeter (7mg/cm2) averaged over an area of one square centimeter.

(94) "SI" means an abbreviation of the International System of Units.

(95) "Sievert" means 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 (1 Sv = 100 rem).

(96) "Site boundary" means that line beyond which the land or property is not owned, leased, or otherwise controlled by the licensee or registrant.

(97) "Source" material means:

(i) uranium or thorium, or any combination there of, in any physical or chemical form; or

(ii) ores that contain by weight one-twentieth of one percent (0.05 percent) or more of uranium, thorium, or any combination of uranium and thorium. Source material does not include special nuclear material.

(98) "Source of radiation" means any radioactive material or any device or equipment emitting, or capable of producing, radiation.

(99) "Special form radioactive material" means radioactive material which satisfies the following conditions:


(i) it is either a single solid piece or is contained in a sealed capsule that can beopened only by destroying the capsule;

(ii) the piece or capsule has at least one dimension not less than five millimeters(0.197 inch); and

(iii) it satisfies test requirements specified by the U.S. Nuclear Regulatory Commission (NRC) in 10 CFR 71.75 and 71.77, January 1, 1994; 1  except that special form radioactive material constructed prior to July 1, 1985 and meeting the requirements of 10 CFR 71 in effect on June 30, 1983 may continue to be used.


(100) "Special nuclear material" means:


(i) plutonium, uranium-233, uranium enriched in the isotope 233 or in the isotope235, and any other material that the U.S. Nuclear Regulatory Commission, pursuant to the provisions of section 51 of the Atomic Energy Act of 1954, as amended, determines to be special nuclear material, but does not include source material; or

(ii) any material artificially enriched by any of the foregoing but does not includesource material.


1FOOTNOTE -The documents referenced in this Part are available for review and copying at the New York State Department of Labor, State Office Campus, Building 12, Room 509, Albany, NY or the New York State Department of State, 162 Washington Avenue, Albany, NY.


(101) "Special nuclear material in quantities not sufficient to form a critical mass" means uranium enriched in the isotope U-235 in quantities not exceeding 350 grams of contained U-235; uranium-233 in quantities not exceeding 200 grams; plutonium in quantities not exceeding 200 grams; or any combination of them in accordance with the following formula: for each kind of special nuclear material, determine the ratio between the quantity of that special nuclear material and the quantity specified above for the same kind of special nuclear material. The sum of such ratios for all of the kinds of special nuclear material in combination shall not exceed 1. For example, the following quantities

in combination would not exceed the limitation and are within the formula:

175 (grams contained U-235) + 50 (grams U-233) + 50 (grams Pu) = 1

                                               200 200

(102) "State" means the State of New York, unless the context of this Part (rule) clearly

indicates that a different meaning is intended.

(103) "Stochastic effect" means a health effect that occurs randomly and for which the probability of the effect occurring, rather than its severity, is assumed to be a function of dose without threshold. Hereditary effects and cancer incidence are examples of stochastic effects. For purposes of these regulations, probabilistic effect is an equivalent term.

(104) "Stray radiation" means the sum of leakage and scattered radiation.

(105) "Survey" means an evaluation of the radiological conditions and potential hazards incident to the production, use, transfer, release, disposal, or presence of sources of radiation. When appropriate, such evaluation includes, but is not limited to, tests, physical examinations, and measurements of levels of radiation or concentrations of radioactive material present.

(106) "These regulations" mean all parts of Industrial Code Rule 38 (12 NYCRR Part 38).

(107) "Total effective dose equivalent" (TEDE) means the sum of the deep dose equivalent for external exposures and the committed effective dose equivalent for internal exposures.

(108) "U.S. Department of Energy" means the Department of Energy established by Public Law 95-91, August 4, 1977, 91 Stat. 565, 42 U.S.C. 7101 et seq., to the extent that the department exercises functions formerly vested in the U.S. Atomic Energy Commission, its chairman, members, officers and components and transferred to the U.S. Energy Research and Development Administration and to the administrator thereof pursuant to section 104(b), (c) and (d) of the Energy Reorganization Act of 1974 (Public Law 93-438, October 11, 1974, 88 Stat. 1233 at 1237, 42 U.S.C, 5814, effective January 19, 1975) and transferred to the Secretary of Energy pursuant to section 301(a) of the Department of Energy Organization Act (Public Law 95-91, August 4, 1977, 91 Stat. 565 at 577-578, 42 U.S.C. 7151, effective October 1, 1977).

(109) "USNRC" means United States Nuclear Regulatory Commission.


(110) "Unrefined and unprocessed ore" means ore in its natural form prior to any processing, such as grinding, roasting, beneficiating, or refining.

(111) "Use as used in radioactive materials licenses" means to employ or apply radioactive materials for the licensed purpose. It shall include instruction of, and responsibility for, technical and support staff members. It does not include training others in the techniques of use of radioactive materials for the purpose of qualifying for licensure.

(112) "Useful beam" means the radiation which passes through the source or tube-housing port and the aperture of the collimating device when the exposure switch or timer is activated.

(113) "Very high radiation area" means an area, accessible to individuals, in which radiation levels could result in an individual receiving an absorbed dose in excess of 5 Gy (500 rad) in one hour at 1 meter from a source of radiation or from any surface that the radiation penetrates.2


(114) "Waste handling licensees" means persons licensed to receive and store radioactive wastes prior to disposal and/or persons licensed to dispose of radioactive wastes.

(115) "Week" means seven consecutive days starting on Sunday. dispose of radioactive wastes.

(116) "Weighting factor WT for an organ or tissue (T)" means the proportion of the risk of stochastic effects resulting from irradiation of that organ or tissue to the total risk of stochastic effects when the whole body is irradiated uniformly. For calculating the effective dose equivalent, the values of WT are:



Organ or tissue






Red bone marrow






Bone surfaces






Whole body


(a) 0.30 results from 0.06 for each of five “remainder” organs, excluding the skin and the lens of the eye, that receive the highest doses.


2FOOTNOTE -  At very high doses received at high dose rates, units of absorbed dose, gray and rad, are appropriate, rather than units of dose equivalent, sievert and rem.


(b) For purposes of weighting the external whole body dose, for adding it to the internal dose, single weighting factor,  WT  = 1.0, has been specified. The use of other weighting factors for external exposure will be approved on a case-by-case basis until such time as specific guidance is issued.


(117) "Whole body" means, for purposes of external exposure, head, trunk (including male gonads), arms above the elbow, or legs above the knee.

(118) "Worker" means an individual engaged in work under a license or registration issued by the commissioner and controlled by a licensee or registrant, but does not include the licensee or registrant.

(119) "Working level" (WL) means any combination of short-lived radon daughters in 1 liter of air that will result in the ultimate emission of 1.3 x 105  MeV of potential alpha particle energy. The short-lived daughters of radon-222 are: polonium-218, lead-214, bismuth-214, and polonium-214. The short-lived daughters of radon-220 are: polonium-216, lead-212, bismuth-212, and polonium-212.

(120) "Working level month" (WLM) means an exposure to 1 working level for 170 hours (2,000 working hours per year divided by 12 months per year is approximately equal to 170 hours per month).

(121) "Year" means the period of time beginning in January used to determine compliance with the provisions of these regulations. The licensee or registrant may change the starting date of the year used to determine compliance by the licensee or registrant provided that the change is made at the beginning of the year and that no day is omitted or duplicated in consecutive years.

Historical Sec. amd. filed June 10, 1971; repealed, new filed July 6, 1978; amds. filed: June Note: 25, 1985; March 15, 1993; repealed, new filed June 9, 1994 eff. June 29, 1994;              

amd. filed April 15, 1999 eff. May 5, 1999


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