(a) Non-uniform exposures of the skin from X-rays, beta radiation, and/or radioactive material on the skin are to be assessed as specified in this section.

(b) For purposes of demonstrating compliance with §835.202(a)(4), assessments shall be conducted as follows:

(1) Area of skin irradiated is 100 cm2 or more. The non-uniform equivalent dose received during the year shall be averaged over the 100 cm2 of the skin receiving the maximum dose, added to any uniform equivalent dose also received by the skin, and recorded as the equivalent dose to any extremity or skin for the year.

(2) Area of skin irradiated is 10 cm2 or more, but is less than 100 cm2. The non-uniform equivalent dose (H) to the irradiated area received during the year shall be added to any uniform equivalent dose also received by the skin and recorded as the equivalent dose to any extremity or skin for the year. H is the equivalent dose averaged over the 1 cm2 of skin receiving the maximum absorbed dose, D, reduced by the fraction f, which is the irradiated area in cm2 divided by 100 cm2 (i.e., H = fD). In no case shall a value of f less than 0.1 be used.

(3) Area of skin irradiated is less than 10 cm2. The non-uniform equivalent dose shall be averaged over the 1 cm2 of skin receiving the maximum dose. This equivalent dose shall:

(i) Be recorded in the individual's occupational exposure history as a special entry; and

(ii) Not be added to any other equivalent dose to any extremity or skin for the year.

[58 FR 65485, Dec. 14, 1993, as amended at 72 FR 31926, June 8, 2007]