Section 180-4-002 - DEFINITIONSThe following definitions apply:
002.01AIR-PURIFYING RESPIRATOR. An air-purifying respirator is a respirator with an air-purifying filter, cartridge, or canister that removes specific air contaminants by passing ambient air through the air-purifying element. 002.02ANNUAL LIMIT ON INTAKE (ALI). The annual limit on intake (ALI) is the derived limit for the amount of radioactive material taken into the body of an adult worker by inhalation or ingestion in a year. Annual limit on intake (ALI) is the smaller value of intake of a given radionuclide in a year by the reference man that would result in a committed effective dose equivalent of 0.05 Sievert (Sv) (5 roentgen equivalent man (rem)) or a committed dose equivalent of 0.5 Sv (50 rem) to any individual organ or tissue. Annual limit on intake (ALI) values for intake by ingestion and by inhalation of selected radionuclides are given in Table I, Columns 1 and 2, of Appendix 4-B of 180 NAC 4.002.03ASSIGNED PROTECTION FACTOR (APF). The assigned protection factor (APF) is the expected workplace level of respiratory protection that would be provided by a properly functioning respirator or a class of respirators to properly fitted and trained users. Operationally, the inhaled concentration can be estimated by dividing the ambient airborne concentration by the assigned protection factor (APF).002.04ATMOSPHERE-SUPPLYING RESPIRATOR. An atmosphere-supplying respirator is a respirator that supplies the respirator user with breathing air from a source independent of the ambient atmosphere, and includes supplied-air respirators (SARs) and self-contained breathing apparatus (SCBA) units.002.05CLASS. Class is the classification scheme for inhaled material 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.002.06DECLARED PREGNANT WOMAN. A declared pregnant woman is a woman who has voluntarily informed the licensee, in writing, of her pregnancy and the estimated date of conception. The declaration remains in effect until the declared pregnant woman withdraws the declaration in writing or is no longer pregnant.002.07DEMAND RESPIRATOR. A demand respirator is an atmosphere-supplying respirator that admits breathing air to the face piece only when a negative pressure is created inside the face piece by inhalation.002.08DERIVED AIR CONCENTRATION (DAC). The derived air concentration (DAC) is the concentration of a given radionuclide in air which, if breathed by the reference man for working year of 2,000 hours under conditions of light work, (inhalation rate 1.2 cubic meters of air per hour), results in an intake of one annual limit on intake (ALI). Derived air concentration (DAC) values are given in Table I, Column 3, of Appendix 4-B of 180 NAC 4.002.09DERIVED AIR CONCENTRATION-HOUR (DAC-HOUR). A derived air concentration-hour (DAC-hour is 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 radionuclide, in hours. A licensee or registrant may take 2,000 derived air concentration (DAC)-hours to represent one annual limit on intake (ALI), equivalent to a committed effective dose equivalent of 0.05 Sv (5 rem).002.10DISPOSABLE RESPIRATOR. A disposable respirator is a respirator for which maintenance is not intended and that is designed to be discarded after excessive breathing resistance, sorbent exhaustion, physical damage, or end-of-service-life renders it unsuitable for use. Examples of this type of respirator are a disposable half-mask respirator or a disposable escape-only self-contained breathing apparatus (SCBA).002.11DOSE OR RADIATION DOSE. 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, as defined in other paragraphs of this section.002.12DOSIMETRY PROCESSOR. A dosimetry processor is an individual or an organization that processes and evaluates individual monitoring devices in order to determine the radiation dose delivered to the monitoring devices.002.13FILTERING FACEPIECE. A filtering facepiece is a negative pressure particulate respirator with a filter as an integral part of the facepiece or with the entire facepiece composed of the filtering medium, not equipped with elastomeric sealing surfaces and adjustable straps. Dust mask is another term for filtering facepiece.002.14FIT FACTOR. The fit factor is the quantitative estimate of the fit of a particular respirator to a specific individual, and typically estimates the ratio of the concentration of a substance in ambient air to its concentration inside the respirator when worn.002.15FIT TEST. A fit test is the use of a protocol to qualitatively or quantitatively evaluate the fit of a respirator on an individual.002.16HELMET. A helmet is a rigid respiratory inlet covering that also provides head protection against impact and penetration.002.17HOOD. A hood is a respiratory inlet covering that completely covers the head and neck and may also cover portions of the shoulders and torso.002.19INHALATION CLASS. Inhalation class has the same meaning as class.002.20LOOSE-FITTING FACEPIECE. A loose-fitting facepiece is a respiratory inlet covering that is designed to form a partial seal with the face.002.21LUNG CLASS. Lung class has the same meaning as class.002.22NEGATIVE PRESSURE RESPIRATOR. A negative pressure respirator is a respirator in which the air pressure inside the facepiece is negative during inhalation with respect to the ambient air pressure outside the respirator. A tight fitting respirator is another term for a negative pressure respirator.002.23NONSTOCHASTIC EFFECT. A nonstochastic effect is 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 a nonstochastic effect. For purposes of Title 180, a deterministic effect is an equivalent term.002.24PLANNED SPECIAL EXPOSURE. A planned special exposure is an infrequent exposure to radiation, separate from and in addition to the annual occupational dose limits.002.25POSITIVE PRESSURE RESPIRATOR. A positive pressure respirator is a respirator in which the pressure inside the respiratory inlet covering exceeds the ambient air pressure outside the respirator.002.26POWERED AIR-PURIFYING RESPIRATOR (PAPR). A powered air-purifying respirator (PAPR) is an air-purifying respirator that uses a blower to force the ambient air through air-purifying elements to the inlet covering.002.27PRESSURE DEMAND RESPIRATOR. A pressure demand respirator is a positive pressure atmosphere-supplying respirator that admits breathing air to the facepiece when the positive pressure is reduced inside the facepiece by inhalation.002.28QUALITATIVE FIT TEST (QLFT). A qualitative fit test (QLFT) is a pass or fail fit test to assess the adequacy of respirator fit that relies on the individual's response to the test agent.002.29QUANTITATIVE FIT TEST (QNFT). A quantitative fit test (QNFT) is an assessment of the adequacy of respirator fit by numerically measuring the amount of leakage into the respirator.002.29QUARTER. A quarter is the period of time equal to one-fourth of the year observed by the licensee or registrant, approximately 13 consecutive weeks, providing that the beginning of the first quarter in a year coincides with the starting date of the year and that no day is omitted or duplicated in consecutive quarters.002.30REFERENCE MAN. Reference man is the hypothetical aggregation of human physical and physiological characteristics determined by international consensus. These characteristics may be used by researchers and public health workers to standardize results of experiments and to relate biological insult to a common base. A description of the reference man is contained in the International Commission on Radiological Protection Report, ICRP Publication 23, "Report of the Task Group on Reference Man."002.31RESPIRATORY PROTECTIVE EQUIPMENT. Respiratory protective equipment is an apparatus, such as a respirator, used to reduce an individual's intake of airborne radioactive materials.002.32SANITARY SEWERAGE. Sanitary sewerage is a system of public sewers for carrying off waste water and refuse, but excluding sewage treatment facilities, septic tanks, and leach fields owned or operated by the licensee.002.33SELF-CONTAINED BREATHING APPARATUS (SCBA). Self-contained breathing apparatus (SCBA) is an atmosphere-supplying respirator for which the breathing air source is designed to be carried by the user.002.34STOCHASTIC EFFECT. A stochastic effect is a health effect that occurs randomly and for which the probability of the effect occurring, rather than its severity, is assumed to be a linear function of dose without threshold. Hereditary effects and cancer incidence are stochastic effects.002.35SUPPLIED-AIR RESPIRATOR (SAR). A supplied-air respirator (SAR) is an atmosphere-supplying respirator for which the source of breathing air is not designed to be carried by the user. Airline respirator is another term for a supplied-air respirator.002.36TIGHT-FITTING FACEPIECE. A tight-fitting facepiece is a respiratory inlet covering that forms a complete seal with the face.002.37USER SEAL CHECK. A user seal check is an action conducted by the respirator user to determine if the respirator is properly seated to the face. Examples include negative pressure check, positive pressure check, irritant smoke check, or isoamyl acetate check. Fit check is another term for user seal check.002.38VERY HIGH RADIATION AREA. A very high radiation area is an area accessible to individuals, in which radiation levels from radiation sources external to the body could result in an individual receiving an absorbed dose in excess of 5 Gy (500 rad) in 1 hour at 1 meter from a radiation source or 1 meter from any surface that the radiation penetrates. Note: For the very high doses received at high dose rates, the units of absorbed dose, gray and rad, are appropriate, rather than units of dose equivalent, sieverts and rem.002.39 WEIGHTING FACTOR (W T). The weighting factor (W T) 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 W T are: ORGAN DOSE WEIGHTING FACTORS |
Organ or Tissue | w T |
Gonads | 0.25 |
Breast | 0.15 |
Red Bone Marrow | 0.12 |
Lung | 0.12 |
Thyroid | 0.03 |
Bone Surfaces | 0.03 |
Remainder | 0.30a |
Whole Body | 1.00b |
a0.30 results from 0.06 for each of 5 "remainder" organs, excluding the skin and the lens of the eye, that receive the highest doses.
b For the purpose of weighting the external whole body dose, for adding it to the internal dose, a single weighting factor, w T = 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.
180 Neb. Admin. Code, ch. 4, § 002
Amended effective 6/7/2021