WAC 246-225-030
General requirements -- Plan review. (1)
Before construction, the floor plans and equipment arrangement
of medical installations (new or modifications of existing
installations) utilizing X rays for diagnostic or therapeutic
purposes shall be submitted to:
(a) A qualified expert for determination of shielding
requirements using National Council on Radiation Protection
and Measurements Report No. 49, or equivalent; and
(b) The department for subsequent review.
Review shall not imply approval.
(2) The review of such plans shall not preclude the
requirement of additional modifications should a subsequent
analysis of operating conditions indicate the possibility of
an individual receiving a dose in excess of the limits
required under WAC 246-221-010, 246-221-050, and 246-221-060.
(3) Diagnostic veterinary, podiatric, and dental
facilities shall be exempt from submitting shielding
calculations and floor plans.
(4) In order for the department to provide an evaluation,
technical advice, and official review of the shielding
requirements for a medical radiation installation, a floor
plan drawn to scale and the following data are required:
(a) The normal location of the X-ray tube, along with an
indication of anode-cathode orientation to the cassette
holders;
(b) The limits of the tube travel;
(c) The directions in which the tube is pointed;
(d) Window locations;
(e) The location of the control booth or operator's
position;
(f) The exposure switch location;
(g) The position of the viewing window, if any;
(h) The composition and thickness of the walls;
(i) If more than one story, the height floor-to-floor;
(j) If more than one story, the composition and thickness
of materials in the ceiling or floor;
(k) The make and model of the X-ray machine;
(l) The maximum kVp and mA;
(m) The types of examinations or treatments (for example,
chest, spine, general X-ray, or therapy);
(n) The identification and occupancy of areas adjacent to
the X-ray room;
(o) The anticipated X-ray workload expressed in number of
patients and exposures per week including:
(i) Technique factors used, or milliampere-seconds or
milliampere-minutes per week; and
(ii) Estimates of the percentage of the workload expected
to occur for a particular beam direction.
(5) For new and modified installations only, the
following are minimum design requirements for medical X-ray
machine operator booths. These requirements do not apply to
dental, podiatry, and veterinary installations. See
subsections (6) and (7) of this section for dental panoramic
and cephalometric requirements.
(a) The operator shall be allotted 0.7 sq. meters (7.5
sq. ft.) or more of unobstructed floor space in the X-ray
booths.
(i) The 0.7 sq. meters (7.5 sq. ft.) of minimum space
specified under subsection (5)(a) of this section shall be a
geometric configuration where no dimension is less than 61.0
centimeters (2.0 ft.).
(ii) The allotted space shall exclude an encumbrance by
the console, such as an overhang, cables, or other similar
encroachment.
(iii) An extension of a straight line drawn between any
point on the edge of the booth shielding and the nearest
vertical edge of a vertical cassette holder, corner of the
examination table, or any part of the tube housing assembly
shall not impinge on the unobstructed space.
(iv) The booth walls shall be 2.1 meters (7.0 ft.) or
more and shall be permanently fixed to the floor or other
structure as may be necessary.
(v) When a door or moveable panel is used as the integral
part of the booth structure, it must have a permissive device
which will prevent an exposure when the door or panel is not
closed.
(b) Switch placement. The operator's switch for the
radiographic machine shall be fixed within the booth. The
switch shall:
(i) Be at least 102 centimeters (forty inches) inside the
protected area; and
(ii) Allow the operator to use the available viewing
windows.
(c) Viewing system requirements.
(i) Each booth shall have at least one viewing device
which shall:
(A) Be placed so the operator can view the patient during
exposure; and
(B) Be placed so the operator can have full view of the
entries into the room.
(ii) When the viewing system is a window, the following
requirements also apply:
(A) The window shall have a visible area of 930 square
centimeters (1.0 square foot) or more; and
(B) The glass shall have the same lead equivalence or
more as that required in the booth's wall where the glass is
mounted.
(iii) When the viewing system is by mirrors, the mirrors
shall be located to accomplish the general requirements under
subdivision (i) of this subsection.
(iv) When the viewing system is by electronic means (for
example, TV):
(A) The camera shall be located to accomplish the general
requirements under subdivision (i) of this subsection; and
(B) There shall be an alternate viewing system as a
backup for electronic failure.
(d) New or modified facilities shall maintain a copy of
the floor plan and shielding calculations required under
subsection (1) of this section.
(6) Dimensions of primary beam shielding shall exceed the
largest possible beam size by 30.5 centimeters (one foot) or
more in every direction. Cephalometric primary beam shielding
shall be deemed adequate if, for a maximum workload of twenty
films a week, two-pound lead is installed (for occupied
areas).
(7) A viewing device shall be present in dental panoramic
and cephalometric X-ray installations, so the requirements of
subsection (5)(c) of this section are met.
[Statutory Authority: RCW 70.98.050. 94-01-073, §
246-225-030, filed 12/9/93, effective 1/9/94. Statutory
Authority: RCW 70.98.050 and 70.98.080. 91-15-083 (Order
183), § 246-225-030, filed 7/23/91, effective 8/23/91. Statutory Authority: RCW 43.70.040. 91-02-049 (Order 121),
recodified as § 246-225-030, filed 12/27/90, effective
1/31/91. Statutory Authority: RCW 70.98.080. 87-01-031
(Order 2450), § 402-28-032, filed 12/11/86; 83-19-050 (Order
2026), § 402-28-032, filed 9/16/83; Order 1084, § 402-28-032,
filed 1/14/76. Formerly WAC 402-28-030 (part).]