Air-Purifying Respirator-a respirator with an air-purifying filter, cartridge, or canister that removes specific air contaminants by passing ambient air through the air-purifying element.
Annual Limit on Intake (ALI)- the derived limit for the amount of radioactive material taken into the body of an adult worker by inhalation or ingestion in a year. 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 Sv (5 rem) or a committed dose equivalent of 0.5 Sv (50 rem) to any individual organ or tissue. ALI values for intake by ingestion and by inhalation of selected radionuclides are given in Table I, Columns 1 and 2, of LAC 33:XV.499.Appendix B.
Assigned Protection Factor (APF)- the expected work place 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 APF.
Atmosphere-Supplying Respirator- 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.
Class- a 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.
Constraint (Dose Constraint)-a value above which specified licensee actions are required.
Critical Group-the group of individuals reasonably expected to receive the greatest exposure to residual radioactivity for any applicable set of circumstances.
Declared Pregnant Woman- 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.
Demand Respirator- an atmosphere-supplying respirator that admits breathing air to the facepiece only when a negative pressure is created inside the facepiece by inhalation.
Derived Air Concentration (DAC)- the concentration of a given radionuclide in air which, if breathed by the 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 Table I, Column 3, of LAC 33:XV.499.Appendix B.
Derived Air Concentration-Hour (DAC-Hour)- 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 DAC-hours to represent one ALI, equivalent to a committed effective dose equivalent of 0.05 Sv (5 rem).
Disposable Respirator- 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).
Dosimetry Processor- an individual or an organization that processes and evaluates individual monitoring equipment in order to determine the radiation dose delivered to the monitoring equipment.
Filtering Facepiece ( Dust Mask)- 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 that is not equipped with elastomeric sealing surfaces and adjustable straps.
Fit Factor-a quantitative estimate of the fit of a particular respirator to a specific individual, which typically estimates the ratio of the concentration of a substance in ambient air to its concentration inside the respirator when worn.
Fit Test-the use of a protocol to qualitatively or quantitatively evaluate the fit of a respirator on an individual.
Helmet- a rigid respiratory inlet covering that also provides head protection against impact and penetration.
Hood-a respiratory inlet covering that completely covers the head and neck and may also cover portions of the shoulders and torso.
Inhalation Class-(see Class)
Loose-Fitting Facepiece- a respiratory inlet covering that is designed to form a partial seal with the face.
Lung Class- (see Class)
Negative Pressure Respirator ( Tight Fitting)- a respirator in which the air pressure inside the facepiece is negative during inhalation with respect to the ambient air pressure outside the respirator.
Nonstochastic Effect- 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, deterministic effect is an equivalent term.
Planned Special Exposure- an infrequent exposure to radiation, separate from and in addition to the annual occupational dose limits.
Positive Pressure Respirator-a respirator in which the pressure inside the respiratory inlet covering exceeds the ambient air pressure outside the respirator.
Powered Air-Purifying Respirator (PAPR)- an air-purifying respirator that uses a blower to force the ambient air through air-purifying elements to the inlet covering.
Pressure Demand Respirator-a positive pressure atmosphere-supplying respirator that admits breathing air to the facepiece when the positive pressure is reduced inside the facepiece by inhalation.
Qualitative Fit Test (QLFT)- a pass/fail fit test to assess the adequacy of respirator fit that relies on the individual's response to the test agent.
Quantitative Fit Test (QNFT)-an assessment of the adequacy of respirator fit by numerically measuring the amount of leakage into the respirator.
Quarter- a period of time equal to 1/4 of the year observed by the licensee, 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.
Reference Man- a hypothetical aggregation of human physical and physiological characteristics determined by international consensus. These characteristics may be used by researchers and public health employees 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."
Respiratory Protective Equipment- an apparatus, such as a respirator, used to reduce an individual's intake of airborne radioactive materials.
Sanitary Sewerage- a system of public sewers for carrying off wastewater and refuse, but excluding sewage treatment facilities, septic tanks, and leach fields owned or operated by the licensee or registrant.
Self-Contained Breathing Apparatus (SCBA)- an atmosphere-supplying respirator for which the breathing air source is designed to be carried by the user.
Stochastic Effect- 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 examples of stochastic effects. For purposes of these regulations, probabilistic effect is an equivalent term.
Supplied-Air Respirator (SAR) or Airline Respirator-an atmosphere-supplying respirator for which the source of breathing air is not designed to be carried by the user.
Tight-Fitting Facepiece- a respiratory inlet covering that forms a complete seal with the face.
User Seal Check (Fit Check)-an action conducted by the respirator user to determine if the respirator is properly seated to the face (e.g., negative pressure check, positive pressure check, irritant smoke test, or isoamyl acetate check).
Very High Radiation Area- an area, accessible to individuals, in which radiation levels external to the body 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.1
Weighting Factor [wT for an Organ or Tissue (T)]- 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 Dose Weighting Factors | ||
Organ or Tissue | wT | |
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 five "remainder" organs, excluding the skin and the lens of the eye, that receive the highest doses.
bFor the purpose of weighting the external whole body dose, for adding it to the internal dose, a 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.
1At very high doses received at high dose rates, units of absorbed dose (e.g., gray and rad) are appropriate, rather than units of dose equivalent (e.g., sievert and rem).
La. Admin. Code tit. 33, § XV-403