RADIATION SAFETY PROGRAM MANUAL

UNC SCHOOL OF DENTISTRY RADIATION SAFETY PROGRAM MANUAL Table of Contents Operating and Safety Procedures Manual………………………………………………………p.1-6 Personne...
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UNC SCHOOL OF DENTISTRY

RADIATION SAFETY PROGRAM MANUAL

Table of Contents Operating and Safety Procedures Manual………………………………………………………p.1-6 Personnel training and RSO…………………………………………………………………………..p.1-2 Radiographic Examinations…………………………………………………………………………..p.2 Operating Radiographic Equipment……………………………………………………………….p.2 Shielding Operator and patient………………………………………………………………………p.3 ALARA………………………………………………………………………………………………………..p.3 Exposure limits and monitoring…………………………………………………………………….p.5-6 Quality Assurance program…………………………………………………………………………...p.6 Background Information and References Appendix A (employee safety plan documentation form)………………………………....p.7 Appendix B (ALARA quick reference)……………………………………………………………..p.8 Appendix C (Considerations for pregnant workers; quick reference)…………………p.9-12 Letter for declaring pregnancy form……………………………………………………………….p.12 North Carolina General Provisions on Radiation Protection Chapter 11…………….p.13-24 Revised and Updated January 2009 Madge B. Webster, BSRT Dr. Enrique Platin, PhD Revisions made from February 2001 Dr. Enrique Platin, PhD Revisions made January 2012 Madge B. Webster, BSRT

OPERATING AND SAFETY PROCEDURES FOR RADIOGRAPHY

____UNC School of Dentistry_______

The North Carolina Division of Radiation Protection enforces the radiation rules in North Carolina. These rules require that radiation machines meet specific requirements. The rules also require that certain procedures be followed and that certain records be kept. A copy of the North Carolina Regulations for Protection against Radiation (NCRFPAR) is always available for review at the following Web address www.ncradiation.net THE USE OF IONIZING RADIATION AND AUXILIARY EQUIPMENT The procedures in this document are intended to minimize radiation exposure to x-ray personnel and patients while maximizing diagnostic quality. You (the employee) are required to know the procedures and requirements outlined in this document. After reading this manual, completing a post test and demonstrating that you can use the machines safely and correctly, you must sign and date the "Record for Instruction of Individuals in Operating and Safety Procedure". (See Appendix A) [Section .0203 a] requires that the individual responsible shall apply for registration within 30 days following the initial operation of the facility and each x-ray machine. This notification of Registration, Plan Reviews, Letter of Acknowledgement, Reports of Assembly and Post installation Surveys are located in _________EHS office UNC Campus____________.

Notice to Employees Postings informing employees of their employer’s responsibility and the responsibility of the employee will be available within this manual and posted in all areas where radiographic equipment is used pursuant to regulation .1002 (c) of the NC regulations. 1.

Personnel Training An individual shall be chosen and be responsible for radiation protection of that facility. [Section .0203 b] requires a named person responsible for radiation protection in the facility. ______Donald Tyndall____ is the Radiation Safety Officer (RSO) and has the responsibility and authority for overseeing matters relating to radiation protection. The RSO also confirms all training and serves as the contact person with the state. Employees should submit all radiation questions or concerns about radiation safety to the RSO.

In compliance with section .0603 General Requirements: Persons employed who will be expected to expose radiographic images will:

2.

1.

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Complete training and show proficiency in the mechanical operation of all intra and extraoral imaging equipment which includes but not limited to: a. location of power both main and emergency cut offs b. location and use of technique and exposure controls c. location of technique charts d. location and storage of digital receptors e. digital scanning and storage devices. f. infection control procedures established for radiography equipment, receptors and workspace.

X-Ray Examinations A doctor or individuals that possess the appropriate authority as permitted by their scope of practice may prescribe all x-ray examinations and film “retakes”. [Rule .0603(a)(1)(F)] The UNC School of Dentistry prescribes such requests through an electronic patient care system via a password protected electronic signature.

While operating radiographic equipment the employee shall: 1. Not allow anyone in the room with the patient during an x-ray examination. If other persons are needed for the examination, they must wear lead aprons and must follow safe radiation procedures and keep out of the direct path of the beam. 2. Remove any unnecessary staff or other persons from the room during the x-ray examination. [Rule .0603 (a) (1) (E)] 3. Stay in the control booth (station, behind the barrier or any other administratively controlled areas etc.) during each exposure. [Rule .0607 (b) (2) (i)] Always maintain visual and aural contact with the patient through the leaded glass, or mirror. [Rule .0604 (b) (1) (C)]. Halt hallway foot traffic during exposure of x-ray equipment to ensure safety of others. 4. Use film holders for all examinations to eliminate patients from holding films with their hands. The XCP instrument has been selected as the image receptor holding device of choice for the UNC School of Dentistry and shall be use at all times unless contraindicated by the patient’s condition. [.0603(a)(1)(H)] 5 Use the technique charts or manual to determine proper exposure (time, kilovoltage, etc.) Don't rely on memory for setting techniques. [Rule .0603 (a) (1) (C)] Technique charts are maintained and updated as needed and their proper use should result in diagnostic images. 6. For extraoral systems: restrict the x-ray beam to the area of clinical interest. The beam size must not be larger than the image receptor. The method you use for restricting the beam is by adjusting the collimator light field to correspond to the size of the film and by following the guidelines provided in the instructions found in the room when appropriate. [Rule .0606 (a)] 7 Align the x-ray beam with the film by using the light localizer and the centering device when appropriate. [Rule .0606 (a) (1) (B)]

3.

Shielding of Operator and Patient 1. The operator will stand behind an approved wall or at least 6 feet away from the x-ray source and not in its direct path while making exposures. Special considerations must be made for administratively controlled areas where indicators have been placed to ensure operator safety from primary beam. 2. Patients will be provided with a lead apron while undergoing radiographic procedures. Separate thyroid shields will be used. If a thyroid shield is not available positioning of the apron will be such that the thyroid area is covered. [Rule.0603(a)(1)(F)] Note: A lead apron of .25mm of lead effectively reduces scatter exposure by 95%. 3. Use mechanical holding devices when a patient or the film must be held. [Rule .0603 (a) (1) (H) (i)] In the event a patient or film must be held as it may be required when imaging special care patients and small children, the individual selected to do the holding must wear a lead apron and lead gloves. Individuals will be selected on the basis of skill and number of times they have held patients. The same person must not be allowed to regularly hold patients. The holder should be a person that: [Rule .0603 (a)(1)(H)] a. is not pregnant or potentially pregnant; b. is over the age of 18 c. has seldom held a person during a x-ray examination. 4.

Never allow the patient to hold the tube housing or the support housing during any exposure. The tube housing must not drift or move during the exposure. If a problem with stability of the suspension arm develops, notify the RSO. [Rule .0607 (h)] 5. When other patients can't be removed from the area, place a mobile protective barrier between the beam and any other patient who remains in the room during the examination. [Rule .0603(a) (E) (iv)] Note: Time, distance and shielding are the three basic principles of radiation protection.

Principles of ALARA All forms of radiation is potentially harmful: In accordance with [Rule .0603(a)(1)(I) & .1606 (b)] this facility endeavors to practice ALARA (As Low As Reasonable Achievable) principle by complying with protection standards described in the above sections. (See Appendix B – quick reference) Pregnant workers & patients Pregnant workers are required to read and sign information regarding this policy and their rights. (See Appendix C- quick reference for forms) There are no established contra indications for obtaining dental radiographs on pregnant patients if treatment necessitates radiographic images. Patients of childbearing age will be asked prior to x-ray exam if they may be pregnant. If disclosed the patient will be informed of the risks from dental x-rays and the option to decline radiographic exam. As with all patient having radiographic procedures protection with appropriate shielding will be employed. 4.

Mobile/Portable Devices 1. Operators of mobile equipment shall ask anyone within 6 feet of the x-ray tube and/or patient to move further away until the exposure is complete. 2. The operator shall stand as far as possible (at least 6 feet) from the tube when executing an exposure. 3. Individual who must remain within 6 feet of the tube shall be protected by whole body aprons or barriers of at least .25mm lead equivalence. 4. The operator will give a verbal warning before exposure is made.

Radiation Exposure Limits & Monitoring Personnel (Monitoring) The UNC School of Dentistry makes available Thermo Luminescent dosimeter (TLD) monitoring badges to individuals who routinely expose patients to radiation. The UNC School of Dentistry has monitored its personnel for 30+ years. Dosimetry readings are consistently below the legal limit for radiation workers. Dosimetry badges are changed and readings are made on a quarterly basis; records are kept in the UNC Environment Health & Safety office on campus. They may be contacted at 962-5715 for review. Employees who participate in the monitoring program are required to wear their personnel monitoring badge. Badges should be worn on the collar or at the waist. If you wear a lead apron, the badge shall be worn outside of the apron. [Rule .0603 (a) (1) (J)] When not in use, store badges at work in a low radiation area, do not wear badge outside the work place. The control badge shall also be stored in a radiation free area. _____Jane Isley_____ is responsible for the exposure records and exchanging the badges If you suspect there has been an excessive exposure or radiation incident, immediately notify the RSO (Dr. Donald Tyndall) who will then notify the UNC Radiation Safety Office. UNC Radiation Safety Office contact numbers: 962-5507 962-6565 via UNC campus police

UNC Dental School RSO Dr. Donald Tyndall 843-4655

Try to keep your personal radiation exposure as low as you can. Be aware of where you are standing and how long you stay in the radiation area. Do not enter or remain in a radiation area unless it is necessary.

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Occupational Exposure Annual limits are as follows: 1. the total effective dose equivalent being equal to five rems (5000 millirems) (0.05Sv); or 2. the sum of the deep-dose equivalent and the committed dose equivalent to any individual organ or tissue other than the lens of the eye being equal to 50 rems (0.5 Sv); and The annual limits to the lens of the eye, to the skin of the whole body, and to the skin of the extremities which are: (A) an eye dose equivalent of 15 rems (0.15 Sv), and (B) a shallow-dose equivalent of 50 rems (0.50 Sv) to the skin of the whole body or to the skin of any extremity. The annual limit for a declared pregnant worker or patient is .05 rem (500 millirems/ pregnancy)

General Public Exposures Each licensee or registrant shall conduct operations so that: 1. The total effective dose equivalent to individual members of the public from the licensed or registered operation does not exceed 0.1 rem (1 mSv) in a year. 2. The dose in any unrestricted area from external sources of radiation, does not exceed 0.002 rem (0.02 mSv) in any one hour. Note: If annual exposure is expected to be above 10% of the dose limit the worker is required to be monitored. Dental personnel receive annual doses of less than 100 millirems.

Exceeding Exposure Limits [15A NCAC 11 .1647] In accordance to the above rule the UNC School of Dentistry will provide a report to the UNC Environmental and Safety office exposures that exceed normal readings. The UNC Environmental and Safety office will then provide reports as required to the appropriate agencies within 30 days. In the event a qualified excessive exposure or radiation incident has occurred the following information will be forwarded to DHSR/ Radiation Protection Section in Raleigh.

Who to notify: DHSR/Radiation Protection Section 1645 Mail Service Center Raleigh, NC 27699-1645 Phone 919.571.4141 Information to provide: Name of person(s) involved Social Security number Date of birth Cause of elevated exposure and estimated dose Corrective Action Quality Assurance Program The UNC School of Dentistry follows a comprehensive program to promote consistent quality by maintaining and monitoring the integrity of all imaging devices specifically the PSP receptors and scanners. Intra and Extraoral equipment is monitored annually by the UNC Environmental and Safety office. Registered technical service providers are used to service equipment when needed; records are available for review. 6

Appendix A (Copy and use this form for all employees) SAFETY PROCEDURE INSTRUCTION AND SAFETY OPERATION OF X_RAY EQUIPMENT. In accordance with NCRFPAR, these procedures have been made available to each individual who operates the x-ray equipment. I certify that each of the individuals listed below has demonstrated to me, on the date indicated, that he/she is competent in these operating and safety procedures and can operate our x-ray equipment in a safe manner. Observation and feedback demonstrated this.

_____________ Date

___________________________________ Signature of RSO

Operator Statement: I have read these procedures and agree to abide by them. Please circle applicable title Staff

Resident

_____________ Date

Faculty

___________________________________ Signature of Operator

Link to post test: http://ehs.unc.edu/training/self_study/dentistry/ Copy and paste this in the address line of your computer Click on “Post Test” **You will need your Onyen and password to access the test

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Appendix B

NORTH CAROLINA RADIATION PROTECTION SECTION Quick Reference Guide

ALARA

Rule .0104 (10) “as low as reasonably achievable” making every reasonable effort to maintain exposures to radiation as far below the dose limits 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 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. Since the mid-1950’s radiation safety standards have included provisions for incorporating the philosophy of As Low As Reasonably Achievable in safety programs. (65) DOSE LIMITS “Limits” or “dose limits” means the permissible upper bounds of radiation dose. Dose limits represent an acceptable level of potential risk and do not represent a level that will necessarily be unsafe if they are exceeded. Rule .1604 (a) The licensee or registrant shall control the occupational dose to individual adults Total effective dose equivalent (TEDE) being equal to five rems (5000 mrem) (0.05Sv), which is the NRC occupational dose limit. Total effective dose equivalent for general public, non-occupational dose limit is 0.1 rems (100 mrem) (1 mSv) Total Organ does equivalent (TODE) is 50 rems (50,000 mrem) (.5 Sv) Eye dose equivalent 15 rems (15,000 mrem) (.15 Sv). Shallow dose equivalent (SDE) 50 rems (50,000 mrem) (.5 Sv). The facility should set action limits for the eventuality for exposure. Level I- Those persons with TEDE that are less than one tenth the acceptable dose limit for occupational and non- occupational- No action is necessary Level II - Those Exposures should be reported to Radiation Safety Committee by the RSO Level III - The RSO will investigate the cause of the high exposure, and any necessary preventive action. An incident report may be needed. Rule .1641 Records of Dose to Individual Members of the Public (a) Each licensee or registrant shall maintain records sufficient to demonstrate compliance with dose limit for individual members of the public required by Rule .1611. These records may include such things as survey results, monitoring results, calculations and other documents pertaining to the determination of doses to individual members of the public. (b) The licensee or registrant shall retain the records required by paragraph (a) of this rule until the agency terminates each pertinent license or registration requiring the record.

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Appendix C

Special Considerations for the Pregnant Radiation Employee Effects of Exposure to Radiation and Other Environmental Hazards This document attempts to explain the risks associated with radiation and pregnancy and compares these risks with other risks to the unborn child. This will assist the pregnant, occupationally exposed employee in assessing the potential risk to the unborn child during the course of employment. Also discussed are methods of minimizing the radiation dose and the risk to the unborn child and maintaining the radiation doses as low as reasonably achievable. Everyone is exposed daily to various kinds of radiation: heat, light, ultraviolet, microwave, ionizing, and so on. All human activities involve exposure to radiation. People are exposed to different amounts of background ionizing radiation depending on where they live, what they eat and drink, and how they live. Background radiation comes from many sources: radon, soil, rocks, cosmic rays, water, air, consumer products, etc. The average person is exposed to approximately 360 mrem per year from these background sources of ionizing radiation. To understand the potential effects of different levels of radiation on an embryo/fetus, it is helpful to compare them to the naturally occurring effects and the environmentally produced risks such as smoking and drinking. This will allow someone to contrast these risks with those produced by exposure to ionizing radiation. The natural risks for birth defects are as follows: 3-5% of all births have some type of abnormality detectable at birth and 3-5% of all births have some type of condition or disease that develops later in life (not detectable at birth). The risk of a known pregnancy ending in a miscarriage or stillbirth is 20-30%. The following table compares the radiation risks (childhood cancer, abnormalities) and nonradiation risks (stillbirth or spontaneous abortion due to high-risk occupations such as the lead industry, fetal alcohol syndrome and perinatal death due to alcohol or smoking) with their natural occurrence as birth defects. References: Cunningham, Gary F. et al. Williams Obstetrics, 19th Edition; Appleton and Lange: Norwalk, CT, 1993. National Council on Radiation Protection and Measurements. Exposure of the Population in the United States and Canada from Natural Background Radiation. NCRP Report No. 94, 1987. National Council on Radiation Protection and Measurement. Radiation Exposure to the U.S. Population from Consumer Products and Miscellaneous Sources. NCRP Report No. 95, 1987. U.S. Nuclear Regulatory Commission. Instruction Concerning Prenatal Radiation Exposure. Regulatory Guide 8.13, 1987.

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Nuclear Regulatory Commission and the North Carolina Radiation Protection Section Regulations and guidance are based on the conservative assumption that any amount of radiation, no matter how small, can have a harmful effect on an adult, child, or unborn child. Because it is known that the unborn child is more sensitive to radiation than adults, particularly during certain stages of development, a special dose limit for protection of the unborn child has been established. Such a limit could result in job discrimination for women of child-bearing age, and perhaps an invasion of privacy (if pregnancy tests were required). Therefore, the regulatory agencies have taken the position that special protection of the unborn child should be voluntary and should be based on decisions made by workers and by employers who are well informed about the risks involved. It is important that the employee understand the risk to the unborn child from radiation received as a result of the occupational exposure of the mother.

Radiation Dose Limits Because of the sensitivity of the unborn child, the North Carolina Regulations For Protection Against Radiation and the Code of Federal Regulations Part 20 have recommended that the dose equivalent to the unborn child from occupational exposure of the expectant mother be limited to 500 mrem for the entire pregnancy. This radiation exposure limit can only be enforced if the pregnancy is declared by the mother. A declared pregnancy is one in which a woman voluntarily informs her employer, in writing, of her pregnancy and gives the estimated date of conception. An employee can declare her pregnancy by filling out a Pregnancy Certification Form available from Radiation Safety.

Advice for Employee and Employer Although the risks to the unborn child are small under normal working conditions, it is a regulatory requirement to limit the radiation dose from occupational exposure to not more than 500 mrem for the total pregnancy and to not more than 50 mrem in any month. Employee and employer should work together to decide the best method for accomplishing this goal. Some methods that might be used include: reducing the time spent in radiation areas, wearing some shielding over the abdominal area, and keeping an extra distance from radiation sources when possible. The Radiation Safety Officer will be able to estimate the probable dose to the unborn child during the normal nine-month pregnancy period based on the exposure history. If the predicted dose approaches the limit, the employee and employer should work out schedules or procedures to confine the dose to less than the 500 mrem required limit.

Internal Hazards Workers should be aware that radiation exposure to the fetus could be from internal sources as well as from external sources. In workplaces such as nuclear medicine clinics and research laboratories where unsealed radioactive materials are routinely used, there is a greater risk of radioactive material entering the body. Pertinent standard radiation precautions include the following: 1. Never smoke, eat, drink, or apply cosmetics where radioactive materials are used. 2. Never pipette by mouth. 3. Use disposable gloves while handling radioactive materials. 4. Wash hands and monitor for radioactive contamination frequently. 5. Wear lab coats or other protective clothing around loose radioactive material. 6. Use certified ventilation hoods when handling volatile or potentially volatile radionuclides. 10

NORTH CAROLINA RADIATION PROTECTION SECTION Quick Reference Guide

Pregnancy-Employee/Patient

Rule .1610 (a) The licensee or registrant shall ensure that the dose to an embryo/fetus during the entire pregnancy, due to occupational exposure of a declared pregnant woman, does not exceed 0.5 rem (5 mSv). Record keeping requirements for doses to an embryo/fetus are provided in Rule .1640. (b) The licensee or registrant shall make efforts to avoid substantial variation above a uniform monthly exposure rate to a declared pregnant woman so as to satisfy the limit in paragraph (a) of this rule. © The dose to an embryo/fetus shall be taken as the sum of: (1) the deep-dose equivalent to the declared pregnant women; and (2) the dose to the embryo/fetus from radionuclides in the embryo/fetus and radionuclides in the declared pregnant woman. (d) If the dose to the embryo/fetus is found to have exceeded 0.5 rem (5 mSv) of this dose, by the time the woman declares the pregnancy to the licensee, the licensee shall be deemed to be in compliance with paragraph (a) of this rule, if the additional dose to the embryo/fetus does not exceed 0.05 rem (.5 mSv) during the remainder of the pregnancy. In recognition of the possibility of increased radiation sensitivity, and because dose to the embryo/fetus is involuntary on the part of the the embryo/fetus, this more restrictive dose limit has been established for the embryo/fetus of a declared pregnant radiation worker. Rule .0104 As a rule the following definitions shall apply. (28) “Declared pregnant woman” means a woman has voluntarily informed the licensee or registrant, 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. (42) “Embryo/Fetal” means the developing human organism from conception until time of birth. A number of studies have suggested that the embryo/fetus may be more sensitive to ionizing radiation than adults, especially during the first trimester of gestation. The National Council on Radiation Protection and Measurement (NCRP) has recommended that special precautions be taken to limit exposure when an occupationally exposed woman could be pregnant. Genetic effects are those that affect the offspring of exposed persons, usually in the range of 20-200 rem. At normal exposure levels, genetic effects of radiation are negligible. It is the responsibility of the Radiology employee to inform (declare) the supervisor that they may be pregnant, this declaration should be in writing, with estimated due date. Until there is a declaration of pregnancy, the occupational dose limits shall remain those guidelines set for adult employees. Declaration of Pregnancy should include: Your name Estimated date of conception/or due date The date you signed the Declaration of Pregnancy To declare pregnancy, no documented medical proof is necessary. MUST BE IN WRITING, This legally protects the employee and the employer 1645 Mail Service Center, Raleigh, North Carolina 27699-1645 Phone: (919) 571-4141 Fax: (919) 571-4148

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Declaration of Pregnancy should include: Your name Estimated date of conception/or due date The date you signed the Declaration of Pregnancy To declare pregnancy, no documented medical proof is necessary. MUST BE IN WRITING, This legally protects the employee and the employer 1645 Mail Service Center, Raleigh, North Carolina 27699-1645 Phone: (919) 571-4141 Fax: (919) 571-4148 Once declaration of Pregnancy is signed: Employee should be counseled by her supervisor and/or the RSO, to include: 1. Review of exposure history 2. Educational review on exposure levels for unborn children (maximum permissible dose, 0.5 rem) and fetal risk associated with exposure to radiation. 3. Discussion of employees work schedule, supervisor, RSO or employee may ask for reassignment to minimize exposure. 4. Supply Declared pregnant worker with a monitor for fetal dose.

Availability of additional information Rule .1640 Record Keeping (f) The licensee or registrant shall maintain the records of dose to an embryo/fetus with the records of dose to the declared pregnant woman. The declaration of pregnancy shall also be kept on file, but may be maintained separately from dose records. The general principles for maintaining exposure to radiation as low as reasonable achievable are time, distance and shielding. Decrease your time near radiation source, increase your distance from the radiation source, and increase the shielding between you and the radiation source. For Patients who may be pregnant All patients in their reproductive years between 12 and 45 should be questioned as to the possibility of pregnancy. This should be done as sensitively and unobtrusively as possible, in keeping a woman’s privacy and dignity in tact. If there is the possibility that pregnancy is likely, the Radiologist should be notified and a pregnancy test should be recommended. If the patient is pregnant: Attending/referring physician should be notified Physician should decide if x-ray is necessary at this time If needed, patient must be thoroughly informed of risks associated with radiation and the embryo/fetus- the decision for x-ray-s exam must be left up to the patient. If the patient decides to proceed with the x-ray examination, the patient should be shielded, shielding shall be documented and a signed waiver should be obtained. If the exam is in the abdominal region, a modified x-ray exam may be necessary, consult with the physician and/or RSO 24 Rule .1611 The Lower limit for declared pregnant radiation worker is 0.5 rem, but for the general population the limit from licensed or registered operations is not to exceed 0.1 rem (1 mSv) in a year. The risk to embryo/fetus from 0.5 rem or even 5 rem of radiation exposure is relatively small compared with some other avoidable risk, such as alcohol consumption and cigarette smoking. 1645

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FORM LETTER FOR DECLARING PREGNANCY (copy and file in employee’s file) This form letter is provided for your convenience. To make your written declaration of pregnancy, you may fill in the blanks in this form letter, you may use a form letter the licensee has provided to you, or you may write your own letter.

DECLARATION OF PREGNANCY To: _________________________ In accordance with the NRC's regulations at 10 CFR 20.1208, "Dose to an Embryo/Fetus," I am declaring that I am pregnant. I believe I became pregnant in________________ (only the month and year need be provided). I understand the radiation dose to my embryo/fetus during my entire pregnancy will not be allowed to exceed 0.5 rem (5 millisievert) (unless that dose has already been exceeded between the time of conception and submitting this letter). I also understand that meeting the lower dose limit may require a change in job or job responsibilities during my pregnancy. ___________________________ (Your Signature) ___________________________ (Your Name Printed) ___________________________ (Date)

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Chapter 11 Radiation Protection General Provisions Section .0100 Effective November1, 2001 I.

Scope [15A NCAC 11 Section .0101]

SCOPE (a) Except as otherwise specifically provided these Rules apply to all persons who receive, possess, use, transfer, own or acquire any source of radiation within the State of North Carolina. (b) Nothing in these Rules shall apply to any person to the extent any person is subject to regulation by the United States Nuclear Regulatory Commission. (c) Regulation by the State of North Carolina of source material, byproduct material, and special nuclear material in quantities not sufficient to form a critical mass is subject to the provisions of the "Agreement Between the United States Atomic Energy Commission and the State of North Carolina for Discontinuance of Certain Commission Regulatory and Responsibility within the State Pursuant to Section 274 of the Atomic Energy Act of 1954, as Amended" under provisions of Public Law 86-373, as amended, and 10 CFR Part 150. History Note: Authority G.S. 104E-2; 104E-7, 104E-10104E-7(a)(2); 104E-12(a); Eff. February 1, 1980; Transferred and Recodified from 10 NCAC 3G .2201 Eff. January 4, 1990; Amended Eff. June 1, 1993.

II.

Prohibited Uses [15A NCAC 11 Section .0110]

(a) Hand-held fluoroscopic screens shall not be used. (b) Shoe-fitting fluoroscopic devices shall not be used. (c) Effective February 1, 1981, plastic pointed position indicating devices on intraoral dental systems shall not be used. (d) Effective February 1, 1983, mechanical timers on intraoral dental machines shall not be used. (e) Dental fluoroscopy without image intensification shall not be used. (f) Non-intensified photofluorographic equipment shall not be used. History Note: Authority G.S. 104E-7; Eff. February 1, 1980; Amended Eff. June 1, 1989; Transferred and Recodified from 10 NCAC 3G .2211 Eff. January 4, 1990.

III.

Registration Of Radiation Machines: Facilities And Services [15A NCAC 11 Section .0200]

This Section .0200, Chapter 11 of Title 15A of the North Carolina Administrative Code (T15A.11 .0200); REGISTRATION OF RADIATION MACHINES: FACILITIES AND SERVICES; has been transferred and recodified from Section .2300, Subchapter 3G of Title 10 of the North Carolina Administrative Code (T10.03G .2300), effective January 4, 1990. The recodification was pursuant to G.S. 143B279.3. 14

PURPOSE AND SCOPE (a) This Section provides for the registration of radiation machines, radiation machine facilities and persons who provide other radiological services. (b) For purposes of this Section, "facility" means the location at which one or more radiation machines are installed or located within one building, vehicle, or under one roof and are under the same administrative control. (c) In addition to the requirements of this Section, all registrants are subject to the provisions of the other sections of this Chapter. (d) Special requirements for registration of particle accelerators are provided in Section .0900 of this Chapter and are in addition to the requirements of this Section. (e) In addition to the requirements of this Section, all registrants are subject to the annual fee provisions contained in Section .1100 of this Chapter. History Note: Authority G.S. 104E-7; 104E-9(8); 104E-19(a); Eff. February 1, 1980; Amended Eff. May 1, 1993; July 1, 1982

Application: Registration: Radiation Machines: Facilities [15A NCAC 11 Section .0203] (a) Each person having an unregistered radiation machine or facility shall: 1. apply for registration of such facility and each radiation machine within 30 days following initial operation of that facility and each radiation machine. Application for registration shall be completed on agency forms and shall contain all information required by the forms and accompanying instructions. The registration of the first radiation machine at a facility constitutes registration of the facility itself. 2. designate on the application form an individual who shall be responsible for radiation protection. (b) Agency forms described in Subparagraph (a)(1) of this Rule require the following and other information: 1. name, address and telephone number of the radiation machine facility; 2. name of the person responsible for radiation protection in the facility; 3. name, training and experience of the person designated in Subparagraph (a)(2) of this Rule; 4. the manufacturer, model number, serial number and type of each radiation machine located within the facility; 5. the date of the application and the signatures of the persons specified in Subparagraphs (b)(2) and (3) of this Rule. History Note: Authority G.S. 104E-7; Eff. February 1, 1980; Amended Eff. May 1, 1992.

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IV. X-ray In The Healing Arts [15A NCAC 11 Section .0600] This Section .0600, Chapter 11 of Title 15A of the North Carolina Administrative Code (T15A.11 .0600); X-RAYS IN THE HEALING ARTS; has been transferred and recodified from Section .2700, Subchapter 3G of Title 10 of the North Carolina Administrative Code (T10.03G .2700), effective January 4, 1990. The recodification was pursuant to G.S. 143B-279.3. PURPOSE AND SCOPE This Section establishes requirements for use of x-ray equipment by or under the supervision of an individual authorized by and licensed in accordance with state statutes to engage in the healing arts or veterinary medicine. The provisions of this Section are in addition to, and not in substitution for, the provisions of Sections .0100, .0200, .0900, .1000, and .1600 of this Chapter. History Note: Authority G.S. 104E-7; Eff. February 1, 1980; Amended Eff. January 1, 1994.

General Requirements [Section .0603]

1.

(a) Administrative Controls Section .0603(1). The registrant is responsible for directing the operation of the x-ray machines under the registration. Section .0603 (1A). An x-ray machine that does not meet the provisions of the regulations shall not be operated for diagnostic purposes. Section .0603(1B). Individuals who will operate the x-ray machine(s) should be adequately instructed in the safe operating procedures and be competent in its safe use. Section .0603(1C). In the area of each x-ray control panel, a technique chart shall be provided of which covers all usual examinations and associated projections that are performed by that system. Section .0603(1D). Written safety procedures and rules shall be established and made available to each individual operating the x-ray equipment under the registrants’ control. Section .0603(1E) (iv). When a portion of the body of a non-occupationally exposed professional staff is potentially subject to stray radiation which would result in the individual receiving 1/4 of the maximum permissible dose per Rule .1604. Additional protective measures shall be employed. Section .0603(1F). Gonadal shielding of not less than 0.5 mm lead equivalent shall be used during radiographic projections except for cases in which this application would interfere with the needed diagnostic information. Section .0603 (1H). When a patient or film must be held during a radiographic procedure then the following applies: i

Mechanical holding devices shall be used whenever medical circumstances permit. Written safety procedures shall indicate the requirements for selecting a holder. 16

ii iii iv

If a human holder is required then written safety procedures are required that document instructions to the person. The human holder shall be protected as required by (1E) of this rule. Lead apron. No individual shall be used routinely to hold patients or film.

Section .0603 (1I). Procedures and auxiliary equipment designed to minimize patient and personnel exposure commensurate with the needed diagnostic information shall be utilized. This includes but is not limited to, the following: i ii

The film speed and screen combination should be the fastest speed consistent with the diagnostic objective of the examinations. The radiation exposure to the patient shall be the minimum exposure required to produce images of good diagnostic quality.

Section .0603(1J). Individuals involved in the operation of the x-ray system(s) that are subject to occupational exposure levels as defined in Rules .1604 and .1638 shall be protected by means of employing a personnel monitoring (film or TLD) system. The dose to the whole body shall be recorded as required by Rule .1614. Section .0603 (a) (2). The registrant shall maintain the following for each x-ray machine: (A) (B) (C)

2.

Current registration information and other correspondence with the agency, regarding each machine. Records and surveys and calibrations. Records of maintenance or modifications that affect the useful beam after the effective date of these regulations, in addition, the persons that performed the service.

Section .0603 (2). The registrant shall maintain the following for each x-ray machine: (A) Current registration information and other correspondence with the agency, regarding each machine. (B) Records and surveys and calibrations. (C) Records of maintenance or modifications that affect the useful beam after the effective date of these regulations, in addition, the persons that performed the service.

(b) Plan Review Section .0603 (b). Prior to construction of structural modification, the floor plans and equipment arrangement of all installations utilizing x-rays for diagnostic purposes shall be reviewed by a qualified expert, and the registrant shall submit the information to the agency.

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(c) Radiation Survey 1. Section .0603 (c). Installations of x-ray equipment after Oct. 1980 and area radiation survey shall be performed within 30 days following initial operation of each medical x-ray machine.

2. 3.

The survey shall also include the following: (A) A drawing of the room in which a stationary x-ray system is located and radiation levels in adjacent areas. (B) The name of the company or person approved by the agency that performed the service, complete with dates. Any modification which could increase the radiation level to any individuals shall require a new survey. Records of surveys are/shall be maintained by the registrant.

History Note: Authority G.S. 104E-7; 104E-12(a); Eff. February 1, 1980; Amended Eff. January 1, 1994; October 1, 1980.

General Requirement for all Diagnostic Systems [15A NCAC 11 Section .0604] (a) In addition to other requirements of this Section, all diagnostic x-ray systems shall meet the following requirements: 1. The control panel containing the main power switch shall bear the warning statement, legible and accessible to view: "WARNING: This x-ray unit may be dangerous to patient and operator unless safe exposure factors and operation instructions are observed." 2. Equivalent wording may be used on battery-powered generators; visual means shall be provided on the control panel to indicate whether the battery is in a state of charge adequate for proper operation. 3. The leakage radiation from the diagnostic source assembly measured at a distance of one meter in any direction from the source shall not exceed 100 millirem in one hour when the x-ray tube is operated at its leakage technique factors. Compliance shall be determined by measurements averaged over an area of 100 square centimeters with no linear dimension greater than 20 centimeters. 4. The radiation emitted by a component other than the diagnostic source assembly shall not exceed two millirem in one hour at five centimeters from any accessible surface of the component when it is operated in an assembled x-ray system under any conditions for which it was designed. Compliance shall be determined by measurements averaged over an area of 100 square centimeters with no linear dimension greater than 20 centimeters. 5. Beam Quality (A) Half-Value Layer (i) The half-value layer (HVL) of the useful beam for a given x-ray tube potential shall not be less than the appropriate value shown in the following table. "Specified Dental System" is any dental x-ray system designed for use with intraoral image receptors and manufactured after December 1, 1980. "Other X-Ray Systems" shall be all other x-ray systems subject to this Section. 18

(vi)

6.

7.

8.

9.

The required minimum aluminum equivalent filtration shall include the filtration contributed by all materials which are always present between the focal spot of the tube and the patient, such as a tabletop when the tube is mounted under the table and inherent filtration of the tube. (B) For new x-ray systems installed after the effective date of these Rules and which have variable kVp and selectable filtration for the useful beam, a device shall link the kVp selector with the filter(s), so that the minimum filtration is always present for the kVp selected. Where two or more radiographic tubes are controlled by one exposure switch, the tube or tubes which have been selected and their location shall be clearly indicated on the master control panel prior to initiation of the exposure. The tube housing assembly supports shall be adjusted such that the tube housing assembly will remain stable during an exposure unless the tube housing movement is a design function of the x-ray system. The location of the focal spot may be indicated on a readily visible area of the xray source housing in the plane parallel to the image receptor when the image receptor is perpendicular to the beam axis. Technique Indicators (A) The technique factors to be used during an exposure shall be indicated before the exposure begins, except when automatic exposure controls are used, in which case the technique factors which are set prior to the exposure shall be indicated. (B) Indication of technique factors shall be visible from the operator's position except in the case of spot films made by the fluoroscopist. (C) On equipment having fixed technique factors, the recommendation in art (a) (9)(A) of this Rule may be met by permanent markings.

(b) Structural Shielding 1. For stationary diagnostic systems, except for intraoral dental systems which shall meet the requirements of Rule .0607(j) of this Section, structural shielding shall be provided to assure compliance with Rules .1604 and .1611 of this Chapter. The following shall be provided: (A) All wall, floor and ceiling areas exposed to the useful beam shall have primary barriers. Primary barriers in walls shall extend to a minimum height of 84 inches above the floor; (B) Secondary barriers in the wall, floor and ceiling areas not having a primary barrier or where the primary barrier requirements are lower than the secondary barrier requirements; and (C) A window of lead-equivalent glass equal to that required by the adjacent barrier or a mirror system shall be provided large enough and so placed that the operator can see the patient without having to leave the protected area during exposures. 2. When a mobile system is used routinely in one location, the structural shielding in that location shall meet the requirements for stationary diagnostic systems in Subparagraph (b)(1) of this Rule. History Note: Authority G.S. 104E-7; Eff. February 1, 1980; Amended Eff. January 1, 1994; October 1, 1980.

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Intraoral Dental Radiographic Systems [15A NCAC 11 Section .0607] (a) In addition to the provisions of Rules .0603 and .0605 of this Section, the requirements of this Rule apply to x-ray equipment and associated facilities used for dental radiography. Criteria for extraoral dental radiographic systems are covered in Rule .0606 of this Section. (b) X-ray systems designed for use with an intraoral image receptor shall be provided with means to limit source-skin distance to not less than: 1. 18 centimeters, if operated above 50 kilovolts peak; or 2. ten centimeters, if operated at or below 50 kilovolts peak. (c) The size of the direct radiation beam shall be limited in accordance with the following rules: 1. Radiographic systems designed for use with an intraoral image receptor shall be provided with means to limit the x-ray beam such that: (A) If the source-skin distance (SSD) is 18 centimeters or more, the x-ray field at the SSD shall be containable in a circle having a diameter of no more than seven centimeters; and (B) If the SSD is less than 18 centimeters, the x-ray field at the SSD shall be containable in a circle having a diameter of no more than six centimeters. 2. Effective February 1, 1981, equipment manufactured prior to August 1974 shall be equipped with a lead line open position indicating device with at least 0.79 mm lead. (d) The timing device shall comply with the following requirements: 1. Termination of the exposure after a preset interval; 2. Termination of exposure shall cause automatic resetting of the timer to its initial setting or to zero; 3. It shall not be possible to make an exposure when the timer is set to a zero or "off" position if either position is provided; and 4. When four timer tests are performed at identical timer settings equal to five seconds or less, the average time period (T) shall be greater than five times the difference between the maximum period (Tmax) and the minimum period (Tmin) in accordance with the formula: T > 5(Tmax- Tmin) 5. Effective February 1, 1983, intraoral dental radiographic systems shall be equipped with an electronic timer. 6. Timer accuracy (A) For indicated values of 0.10 seconds and above, the measured value shall be within plus or minus 15 percent of the indicated values for equipment manufactured before August 1, 1974. (B) For equipment manufactured after August 1, 1974, the deviation of measured values from indicated values shall not exceed the limits specified for that system by its manufacturer. (e) The exposure switch shall comply with the following requirements: 1. A control shall be incorporated into each x-ray system such that an exposure can be terminated at any time, except for exposures of one-half second or less. 2. Each x-ray control shall be located in such a way as to meet the following criteria: (A) For stationary x-ray systems installed after the effective date of this Rule, the exposure switch shall be permanently mounted in a protected area (e.g., corridor outside the room) so that the operator is required to remain in that protected area during the entire exposure. 20

(B)

(f)

(g) (h) (i) (j)

For stationary x-ray systems without a protected area and installed before the effective date of this Rule, the exposure switch shall be such that the operator shall stand at least six feet away from the tube and out of the direct beam. (C) For mobile and portable x-ray systems the switch shall meet the requirements of Part (e)(2)(B) of this Rule. 3. For equipment manufactured after August 1, 1974, the x-ray control shall provide visual indication observable at or from the operator's protected position whenever x-rays are produced. In addition, a signal audible to the operator shall indicate that the exposure has terminated. The exposure produced shall be reproducible to within the following criteria: When all technique factors are held constant, the coefficient of variation shall not exceed 0.10. This shall be deemed to be met if, when four exposures at identical technique factors are made, the value of the average exposure (E) is greater than five times the difference between the maximum exposure (Emax) and the minimum exposure (Emin) in accordance with the formula: E > 5(Emax- Emin) Patient and film holding devices shall be used when the techniques permit. Neither the tube housing nor the position indicating device shall be hand-held during an exposure. Dental fluoroscopy without image intensification shall not be used. Structural shielding 1. All wall, floor and ceiling areas shall have protective barriers sufficient to meet the requirements of Rules .1604 and .1611 of this Chapter. 2. When intraoral x-ray systems are installed in adjacent rooms or areas, protective barriers as specified in Subparagraph (j)(1) of this Rule shall be provided between the rooms or areas.

History Note: Authority G.S. 104E-7; Eff. February 1, 1980; Amended Eff. January 1, 1994; October 1, 1980.

V.

NOTICES: Instructions: Reports And Inspections [15A NCAC 11 Section .1000]

This Section .1000, Chapter 11 of Title 15A of the North Carolina Administrative Code (T15A.11 .1000); NOTICES: INSTRUCTIONS: REPORTS AND INSPECTIONS; has been transferred and recodified from Section .3100, Subchapter 3G of Title 10 of the North Carolina Administrative Code (T10.03G .3100), effective January 4, 1990. The recodification was pursuant to G.S. 143B-279.3. Scope Section .1001 establishes requirements for notices, instructions and reports by licensees or registrants to individuals engaged in work under a license or registration and options available to such individuals in connection with agency inspections of licensees or registrants to ascertain compliance with the provisions of the Act and rules, orders and licenses issued there under regarding radiological working conditions. The rules in this Section apply to all persons who receive, possess, use, own or transfer sources of radiation licensed by or registered with the agency pursuant to the rules in Sections .0200, .0300, .0900 and .1200 of this Chapter. History Note: Authority G.S. 104E-7; 104E-12; Eff. February 1, 1980; Amended Eff. May 1, 1993; June 1, 1989.

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Posting Of Notices To Workers [15A NCAC 11 Section .1002] (a) Each licensee or registrant shall post current copies of the following documents: 1. the rules in this Section and in Section .1600 of this Chapter; 2. the license, certificate of registration, conditions or documents incorporated into the license by reference and amendments thereto; 3. the operating procedures applicable to work under the license or registration; 4. any notice of violation involving radiological working conditions, any order issued pursuant to Section .0100 of this Chapter and any response from the licensee or registrant. (b) If posting of a document specified in Subparagraphs (a)(1), (2) or (3) of this Rule is not practicable, the licensee or registrant may post a notice which describes the document and states where it may be examined. (c) The agency form "Notice to Employees" shall be posted by each licensee or registrant wherever individuals work in or frequent any portion of a restricted area. (d) The agency form "Notice to Employees" contains information to employees regarding employer's responsibility, worker's responsibility, the subjects covered by this Section, reports on radiation exposure history, inspections, and any other information that the agency may include. (e) Documents, notices or forms posted pursuant to this Rule shall appear in a sufficient number of places to permit individuals engaged in work under the license or registration to observe them on the way to or from any particular work location to which the document applies, shall be conspicuous, and shall be replaced if defaced or altered. (f) Agency documents posted pursuant to Subparagraph (a)(4) of this Rule shall be posted within two working days after receipt of the documents from the agency; the licensee's or registrant's response, if any, shall be posted within two working days after dispatch from the licensee or registrant. Such documents shall remain posted for a minimum of five working days or until action correcting the violation has been completed, whichever is later. History Note: Authority G.S. 104E-7; 104E-10; Eff. February 1, 1980; Amended Eff. January 1, 1994; May 1, 1992.

Instructions To Workers [15A NCAC 11 .1003] (a) All individuals who, in the course of employment, are likely to receive in a year an occupational dose in excess of 100 millirem (1 millisievert) shall be kept informed of the storage, transfer, or use of radioactive material or of radiation in such portions of the restricted area; shall be instructed in the health protection problems associated with exposure to such radioactive material or radiation, in precautions or procedures to minimize exposure, and in the purposes and functions of protective devices employed; shall be instructed in, and instructed to observe, to the extent within the worker's control, the applicable provisions of this Chapter and licenses for the protection of personnel from exposures to radiation or radioactive material occurring in such areas; shall be instructed of their responsibility to report promptly to the licensee or registrant any condition which may lead to or cause a violation of rules in this Chapter and licenses or unnecessary exposure to radiation or radioactive material; shall be instructed in the appropriate response to warnings made in the event of any unusual occurrence or malfunction that may involve exposure to radiation or radioactive material; and shall be advised as to the radiation exposure reports which workers may request pursuant to Rule .1004 of this Section. The extent of these instructions shall be commensurate with potential radiological health protection problems in the restricted area. 22

(b) In determining those individuals subject to the requirements of Paragraph (a) of this Rule, licensees or registrants shall take into consideration assigned activities during normal and abnormal situations involving exposure to all sources of radiation and radioactive material which can reasonably be expected to occur during the life of the licensed or registered facility. The extent of these instructions shall be commensurate with the potential radiological health protection problems present in the workplace. History Note: Authority G.S. 104E-7; 104E-10; 104E-12; Eff. February 1, 1980; Amended Eff. April 1, 1999.

II.

Standards For Protection Against Radiation [15A NCAC 11 Section .1600]

Purpose and Scope (a) Section 01601 establish standards for protection against ionizing radiation resulting from activities conducted under licenses and registrations issued by the agency pursuant to the rules in this Chapter. (b) It is the purpose of the rules in this Section to control the receipt, possession, use, transfer, and disposal of sources of radiation by any licensee or registrant in such a manner that the total dose to an individual, including doses resulting from all sources of radiation other than background radiation, does not exceed the standards for protection against radiation prescribed in the rules in this Section. However, nothing in this Section shall be construed as limiting actions that may be necessary to protect health and safety. (c) The rules in this Section apply to persons licensed or registered by the agency to receive, possess, use, transfer, or dispose of radioactive material or other sources of radiation. The limits in this Section do not apply to doses due to background radiation, to exposure of patients to radiation for the purpose of medical diagnosis or therapy, to voluntary participation in medical research programs, or to exposure from individuals administered radioactive material and released in accordance with Rule .0358 of this Chapter. (d) Nothing in this Section shall relieve a licensee engaged in operation of a radioactive waste disposal facility, as defined in Rule .0104 of this Chapter, from responsibility for complying with the requirements in Section .1200 of this Chapter. (e) Effective January 1, 1994 all licensees and registrants shall comply with the rules in this Section and cease to comply with the requirements in Section .0400 of this Chapter, except as provided otherwise in Rule .1602 of this Section. History Note: Authority G.S. 104E-7(a)(2); Eff. January 1, 1994; Amended Eff. August 1, 1998.

Radiation Protection Programs [15A NCAC 11 Section .1603] (a) Each licensee or registrant shall develop, document, and implement a radiation protection program commensurate with the scope and extent of licensed or registered activities and sufficient to ensure compliance with the provisions of this Section. Record keeping requirements relating to these programs are provided in Rule .1636 of this Section. (b) The licensee or registrant shall use procedures and engineering controls based upon sound radiation protection principles to achieve occupational doses and doses to members of the public and releases of radioactive materials in effluents to unrestricted areas that are as low as is reasonably achievable (ALARA). 23

(c) The licensee or registrant shall annually review the radiation protection program content and implementation. (d) To implement the ALARA requirements of Paragraph (b) of this Rule, and notwithstanding the requirements of Rule .1611 of this Section, a constraint on air emissions of radioactive material to the environment, excluding Radon-222 and its daughters, shall be established by licensees such that the individual member of the public likely to receive the highest dose will not be expected to receive a total effective dose equivalent in excess of 0.01 rem (0.1 mSv) per year from these emissions. If a licensee subject to this requirement exceeds this dose constraint, the licensee shall report the exceedance as provided in Rule .1647 of this Section and promptly take appropriate corrective action to ensure against recurrence. History Note: Authority G.S. 104E-7(a)(2); Eff. January 1, 1994; Amended Eff. August 1, 1998.

Occupational Dose Limits For Adults [15A NCAC 11Section .1604] (a) The licensee or registrant shall control the occupational dose to individual adults, except for planned special exposures as provided in Rule .1608 of this Section, to the following dose limits: 1. an annual limit, which is the more limiting of: (A) the total effective dose equivalent being equal to five rems (0.05Sv); or (B) the sum of the deep-dose equivalent and the committed dose equivalent to any individual organ or tissue other than the lens of the eye being equal to 50 rems (0.5 Sv); and 2. the annual limits to the lens of the eye, to the skin of the whole body, and to the skin of the extremities which are: (A) an eye dose equivalent of 15 rems (0.15 Sv), and (B) a shallow-dose equivalent of 50 rems (0.50 Sv) to the skin of the whole body or to the skin of any extremity. (b) Doses received in excess of the annual limits, including doses received during accidents, emergencies, and planned special exposures, shall be subtracted from the limits for planned special exposures that the individual may receive during the current year and during the individual's lifetime. Dose limits for planned special exposures are provided in Item (5) of Rule .1608 of this Section. (c) The assigned deep-dose equivalent shall be for the part of the body receiving the highest exposure. The assigned shallow dose equivalent shall be the dose averaged over the contiguous 10 square centimeters of skin receiving the highest exposure. The deep-dose equivalent, eye dose equivalent and shallow-dose equivalent may be assessed from surveys or other radiation measurements for the purpose of demonstrating compliance with the occupational dose limits, if the individual monitoring device was not in the region of highest potential exposure, or the results of individual monitoring are unavailable. (d) Derived air concentration (DAC) and annual limit on intake (ALI) values are presented in Table 1 of Appendix B to 10 CFR §§ 20.1001 - 20.2401 and may be used to determine the individual's dose and to demonstrate compliance with the occupational dose limits. (e) In addition to the annual dose limits, the licensee shall limit the soluble uranium intake by an individual to 10 milligrams in a week in consideration of chemical toxicity. Requirements for annual limits on intake for uranium are provided in Appendix B to 10 CFR §§ 20.1001 20.2401. (f) The licensee or registrant shall reduce the dose that an individual may be allowed to receive in the current year by the amount of occupational dose received while employed by any other person. Requirements for determining prior occupational exposure are provided in Rule .1638(e) of this Section. History Note: Authority G.S. 104E-7(a)(2); Eff. January 1, 1994; Amended Eff. May 1, 2006.

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Occupational Does Limits For Minors [15A NCAC 11 Section .1609] The annual occupational dose limits for minors are 10 percent of the annual dose limits specified for adult workers in Rule .1604 of this Section. History Note: Authority G.S. 104E-7(a)(2); Eff. January 1, 1994.

NOTES

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