N.H. Admin. Code § He-P 4020.05

Current through Register No. 50, December 12, 2024

Section He-P 4020.05 - Occupational Dose Limits for Adults

(a) The licensee or registrant shall control the occupational dose to individual adults, except for planned special exposures pursuant to He-P 4020.10, to the following dose limits:

(1) An annual limit, which shall be the more limiting of:

a. The total effective dose equivalent being equal to 0.05 Sv (5 rem); 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 0.5 Sv (50 rem); 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 shall be:

a. A lens dose equivalent of 0.15 Sv (15 rem); and

b. A shallow dose equivalent of 0.5 Sv (50 rem) 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.

(c) When the external exposure is determined by measurement with an external personal monitoring device, the deep-dose equivalent shall be used in place of the effective dose equivalent, unless the effective dose equivalent is determined by a dosimetry method acceptable by DHHS/RHS.

(d) The assigned deep dose equivalent shall be for the portion of the body receiving the highest exposure.

(e) The assigned shallow dose equivalent shall be for the dose averaged over the contiguous 10 square centimeters of skin receiving the highest exposure.

(f) The deep dose equivalent, the lens dose equivalent, and the 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.

(g) The effective dose equivalent for external radiation when a protective apron is worn while working with medical fluoroscopic equipment shall be determined as follows:

(1) When one individual monitoring device is used and it is located at the neck outside the protective apron, the reported deep dose equivalent shall be the effective dose equivalent for external radiation;

(2) When only one individual monitoring device is used and it is located at the neck outside the protective apron, and the reported dose equivalent exceeds 25 percent of the limit specified in He-P 4020.05(a) , the reported dose equivalent value multiplied by 0.3 shall be the effective dose equivalent for external radiation; or

(3) When individual monitoring devices are worn, both under the protective apron at the waist and outside the protective apron at the neck, the effective dose equivalent for external radiation shall be assigned the value of the sum of the deep dose equivalent reported for the individual monitoring device located at the waist under the protective apron multiplied by 1.5 and the deep dose equivalent reported for the individual monitoring device located at the neck outside the protective apron multiplied by 0.04.

(h) Derived air concentration (DAC) and annual limit on intake (ALI) values shall be as stated in He-P 4090 and may be used to determine the individual's dose and to demonstrate compliance with the occupational dose limits.

(i) Notwithstanding 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.

(j) 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 during the current year.

N.H. Admin. Code § He-P 4020.05

#5903, eff 2-1-95; ss by #6827, eff 8-6-98; ss by #8481, eff 11-5-05

Amended byVolume XXXIV Number 24, Filed June 12, 2014, Proposed by #10604, Effective 5/23/2014, Expires 5/23/2024.