Pennsylvania Code › Title 25 - ENVIRONMENTAL PROTECTION › Part I - Department of Environmental Protection › Subpart D - Environmental Health and Safety › Article V - Radiological Health › Chapter 221 - X-RAYS IN THE HEALING ARTS › DIAGNOSTIC INSTALLATIONS GENERAL REQUIREMENTS › Section 221.25 - Beam quality

Current through Register Vol. 54, No. 28, July 13, 2024
(a) Diagnostic
						X-ray systems shall have filtration that satisfies the requirements of Table I.
						The requirements of this section shall be considered to have been met if it can
						be demonstrated that the half value layer of the primary beam is not less than
						that shown in Table II.
TABLE I
Filtration Required vs. Operating
						  Voltage
Operating Voltage (kVp)
Total Filtration (inherent plus added) (millimeters
									 aluminum equivalent
)
Below 50
0.5 millimeters
50-70
1.5 millimeters
Above 70
2.5 millimeters
TABLE II
X-Ray Tube Voltage (kilovolt peak)
Design Operating
										Range
Measured Operating
										Potential
Minimum HVL (mm of
										Aluminum)
Specified Dental
									 Systems1
Other X-Ray
									 Systems2
Other X-Ray
									 Systems3
Below 51
30
1.5
0.3
0.3
40
1.5
0.4
0.4
50
1.5
0.5
0.5
51 to 70
51
1.5
1.2
1.3
60
1.5
1.3
1.5
70
1.5
1.5
1.8
Above 70
71
2.1
2.1
2.5
80
2.3
2.3
2.9
90
2.5
2.5
3.2
100
2.7
2.7
3.6
110
3.0
3.0
3.9
120
3.2
3.2
4.3
130
3.5
3.5
4.7
140
3.8
3.8
5.0
150
4.1
4.1
5.4
1 Dental X-ray systems
						  designed for use with intraoral image receptors and manufactured after December
						  1, 1980.
2 Dental X-ray systems
						  designed for use with intraoral image receptors and manufactured before or on
						  December 1, 1980, and all other X-ray systems subject to this section and
						  manufactured before June 10, 2006.
3 All X-ray systems, except
						  dental X-ray systems designed for use with intraoral image receptors, subject
						  to this section and manufactured on or after June 10, 2006.
Note
: Half-value layers for
						  kilovoltages not listed in Table II may be determined by interpolation or
						  extrapolation.
(b) Beryllium
						window tubes shall have a minimum of 0.5 millimeter aluminum equivalent
						filtration permanently installed in the useful beam.
(c) For capacitor energy storage equipment,
						compliance with this section shall be determined with the maximum quantity of
						charge per exposure.
(d) The
						required minimal aluminum equivalent filtration shall include the filtration
						contributed by materials which are always present between the source and the
						patient.
(e) For X-ray systems
						having variable filtration in the useful beam, a means shall be provided to
						prohibit exposure unless the filtration requirements of subsection (a) are met
						for the kVp selected.
The provisions of this §
														221.25 issued and amended under
							 sections 301 and 302 of the Radiation Protection Act (35 P.S.
							 §§
															7110.301 and
							 7110.302); and section 1920-A
							 of The Administrative Code of 1929 (71 P.S. §
															510-20).
This section cited in 25 Pa. Code §
														221.35a (relating to fluoroscopic
							 X-ray systems).