(a) Except as provided in paragraph (b) of this section, no employer
shall possess, use, or transfer sources of ionizing radiation in such a
manner as to cause any individual in a restricted area to receive in any
period of one calendar quarter from sources in the employer's possession
or control a dose in excess of the limits specified in the following
table:
1. Whole body: Head and trunk; active blood-forming organs;
lens of eyes; or gonads.................................... 1\1/4\
2. Hands and forearms; feet and ankles...................... 18\3/4\
3. Skin of whole body....................................... 7\1/2\
(b) An employer may permit an individual in a restricted area to
receive doses to the whole body greater than those permitted under
paragraph (a) of this section, so long as:
(1) During any calendar quarter the dose to the whole body shall not
exceed 3 rems; and
(2) The dose to the whole body, when added to the accumulated
occupational dose to the whole body, shall not exceed 5 (N-18) rems,
where ``N'' equals the individual's age in years at his last birthday;
and
(3) The employer maintains adequate past and current exposure
records which show that the addition of such a dose will not cause the
individual to exceed the amount authorized in this paragraph. As used in
this paragraph ``Dose to the whole body'' shall be deemed to include any
dose to the whole body, gonad, active bloodforming organs, head and
trunk, or lens of the eye.
(c) No employer shall permit any employee who is under 18 years of
age to receive in any period of one calendar quarter a dose in excess of
10 percent of the limits specified in the table in paragraph (a) of this
section.
(d) Calendar quarter means any 3-month period determined as follows:
(1) The first period of any year may begin on any date in January:
Provided, That the second, third, and fourth periods accordingly begin
on the same date in April, July, and October, respectively, and that the
fourth period extends into January of the succeeding year, if necessary
to complete a 3-month quarter. During the first year of use of this
method of determination, the first period for that year shall also
include any additional days in January preceding the starting date for
the first period; or
(2) The first period in a calendar year of 13 complete, consecutive
calendar weeks; the second period in a calendar year of 13 complete,
consecutive calendar weeks; the third period in a calendar year of 13
complete, consecutive calendar weeks; the fourth period in a calendar
year of 13 complete, consecutive calendar weeks. If at the end of a
calendar year there are any days not falling within a complete calendar
week of that year, such days shall be included within the last complete
calendar week of that year. If at the beginning of any calendar year
there are days not falling within a complete calendar week of that year,
such days shall be included within the last complete calendar week of
the previous year; or
(3) The four periods in a calendar year may consist of the first 14
complete, consecutive calendar weeks; the next 12 complete, consecutive
calendar
weeks, the next 14 complete, consecutive calendar weeks, and the last 12
complete, consecutive calendar weeks. If at the end of a calendar year
there are any days not falling within a complete calendar week of that
year, such days shall be included (for purposes of this part) within the
last complete calendar week of the year. If at the beginning of any
calendar year there are days not falling within a complete calendar week
of that year, such days shall be included (for purposes of this part)
within the last complete week of the previous year.
(e) No employer shall change the method used by him to determine
calendar quarters except at the beginning of a calendar year.
