Clarification of Radiation Control 
Regulations 
For Manufacturers of Diagnostic  
X-Ray Equipment 
Draft Guidance for Industry and  
Food and Drug Administration Staff 
 
DRAFT GUIDANCE 
 
This draft guidance document is being distributed for comment purposes only. 
 
Document issued on December 17, 2018. 
 
You should submit comments and suggestions regarding this draft document within 60 days of 
publication in the Federal Register of the notice announcing the availability of the draft 
guidance.  Submit electronic comments to https://www.regulations.gov/.  Submit written 
comments to the Dockets Management Staff (HFA-305), Food and Drug Administration, 5630 
Fishers Lane, rm. 1061, Rockville, MD 20852.  Identify all comments with the docket number 
listed in the notice of availability that publishes in the Federal Register. 
For questions regarding this document, contact the Office of In Vitro Diagnostics and Radiological 
Health at 240-402-5149 and Scott Gonzalez at 301-796-5889 or by email at 
Scott.Gonzalez@fda.hhs.gov.  
When final, this guidance will supersede FDAs guidance entitled Clarification 
of Radiation Control Regulations for Diagnostic X-Ray Equipment (HHS 
Publication FDA 89-8221 issued in March 1989). 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Devices and Radiological Health 
 
 
 
  Contains Nonbinding Recommendations 
 
Draft Not for Implementation 
 
Preface 
 
Additional Copies 
 
Additional copies are available from the Internet.  You may also send an e-mail request to 
CDRH-Guidance@fda.hhs.gov to receive a copy of the guidance.  Please use the document 
number 1500029 to identify the guidance you are requesting   
 
  Contains Nonbinding Recommendations 
 
Draft Not for Implementation 
 
Table of Contents 
 
I. Introduction ................................................................................................................................. 4 
II. Background ................................................................................................................................ 5 
III. Scope ......................................................................................................................................... 5 
IV. General Information for Manufacturers of Diagnostic X-Ray Equipment ............................... 6 
V. Specific Topics of Importance to Manufacturers of Diagnostic X-Ray Equipment .................. 7 
A.  Introduction into Commerce and Certification (see also questions 37, 38, 88, 92, 93, 96, 
97, and 98) ....................................................................................................................... 7 
B.  Labeling (see also questions 45, 79, 99, and 100).......................................................... 11 
(1)  General Labeling ........................................................................................................ 11 
(2)  Label Location ............................................................................................................ 14 
(3)  Certification Labels .................................................................................................... 17 
(4)  Identification Labels ................................................................................................... 18 
(5)  Warning Labels ........................................................................................................... 20 
C.  Date of Manufacture (See also question 29) .................................................................. 21 
D.  Measurements................................................................................................................. 22 
E.  Models (See also question 33) ....................................................................................... 24 
F.  Product Reports .............................................................................................................. 24 
G.  Assembly (See also questions 5, 6, 23, and 38) ............................................................. 25 
(1)  Assembly Instructions (See also questions 51, 53, and 54)........................................ 28 
H.  Accidental Radiation Occurrence................................................................................... 30 
I.  Records ........................................................................................................................... 30 
J.  Defects (See also questions 53 and 54) .......................................................................... 31 
K.  Fluoroscopy (See also question 54) ............................................................................... 33 
L.  Specific components ...................................................................................................... 35 
(1)  Beam Limiting Devices (see also questions 12, 15, 19, 78, and 98) .......................... 35 
(2)  Controls (See also questions 20, 35, and 36) .............................................................. 36 
(3)  Filters .......................................................................................................................... 37 
(4)  Image Receptors ......................................................................................................... 39 
(5)  Mechanical Tomographic Systems ............................................................................. 41 
(6)  Source-image receptor distance (SID) Indicators ....................................................... 41 
(7)  Timers (See also questions 92 and 93) ....................................................................... 42 
(8)  Tube Housing Assemblies (See also questions 12 and 34) ........................................ 42 
 
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Clarification of Radiation Control 
1 
Regulations 
2 
For Manufacturers of Diagnostic  
3 
X-Ray Equipment 
4 
Draft Guidance for Industry and  
5 
Food and Drug Administration Staff  
6 
7   
8  This draft guidance, when finalized, will represent the current thinking of the Food and Drug 
9  Administration (FDA or Agency) on this topic.  It does not establish any rights for any person 
10  and is not binding on FDA or the public.  You can use an alternative approach if it satisfies 
11  the requirements of the applicable statutes and regulations.  To discuss an alternative 
12  approach, contact the FDA staff or Office responsible for this guidance as listed on the title 
13  page.  
14   
15  I. Introduction 
16   
17  This draft guidance provides clarification to industry and FDA staff of the Federal Regulations that 
18  relate to diagnostic x-ray systems and their major components.  This draft guidance, when finalized, 
19  will supersede FDAs guidance entitled Clarification of Radiation Control Regulations for 
20  Diagnostic X-Ray Equipment (HHS Publication FDA 89-8221 issued in March 1989).1  For the 
21  current edition of the FDA-recognized standards referenced in this document, see the FDA 
22  Recognized Consensus Standards Database.2 
23  FDAs guidance documents, including this draft guidance, do not establish legally enforceable 
24  responsibilities.  Instead, guidances describe the Agency's current thinking on a topic and should 
25  be viewed only as recommendations, unless specific regulatory or statutory requirements are 
26  cited.  The use of the word should in Agency guidances means that something is suggested or 
27  recommended, but not required. 
                                                 
1 https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm095312.htm. 
2 https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfStandards/search.cfm. 
 
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28  II. Background 
29   
30  CDRH is charged with the responsibility of enforcing regulations created under the Radiation 
31  Control for Health and Safety Act of 1968 (Public Law 90-602) (the Act).  The Act was later 
32  recodified from Title 42 to Title 21 and incorporated into the Federal Food, Drug, and Cosmetic Act 
33  (FD&C Act) with the passage of the Safe Medical Devices Act of 1990.  The relevant sections from 
34  the Radiation Control for Health and Safety Act were placed into Sections 531 through 542 of the 
35  FD&C Act (21 U.S.C.  360hh through  360ss) under Subchapter C entitled Electronic Product 
36  Radiation Control (EPRC).  The regulations promulgated pursuant to the FD&C Act are covered in 
37  21 CFR Subchapter J-Radiological Health.  The term Radiological Health Regulations, as used in 
38  this document, refers broadly to 21 CFR Subchapter J.  These regulations pertain to the 
39  recordkeeping, reporting, manufacturing, importing, and installation of electronic products as 
40  defined under 21 CFR 1000.3(j).  General Performance Standards for Electronic Products are 
41  covered in 21 CFR Part 1010, while Specific Performance Standards for diagnostic x-ray systems 
42  are covered in Diagnostic x-ray systems and their major components (21 CFR 1020.30), 
43  Radiographic equipment (21 CFR 1020.31), Fluoroscopic equipment (21 CFR 1020.32), and 
44  Computed tomography (CT) equipment (21 CFR 1020.33), which cover aspects of the 
45  performance of each listed type of equipment and place specific requirements on the manufacturers, 
46  importers, dealers, distributors, and assemblers of the covered equipment.  The term Performance 
47  Standards as used in this document refers to these five regulations.   
48   
49  III. Scope 
50   
51  Pursuant to the definitions in sections 201(h) [21 U.S.C. 321(h) and 531 [21 U.S.C. 360hh] of 
52  the FD&C Act, diagnostic x-ray systems are considered to be both medical devices and 
53  electronic products.  As such, these devices are subject to the provisions of the FD&C Act that 
54  apply to medical devices (e.g., sections 510, 520, and of the FD&C Act [21 U.S.C.   360 and 
55  360j], 
56  http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/Overview/default.htm) and 
57  their implementing regulations as well as the provisions of the FD&C Act that apply to 
58  electronic products, known as the EPRC (http://www.fda.gov/Radiation-
59  EmittingProducts/ElectronicProductRadiationControlProgram/LawsandRegulations/default.htm),
60  and their implementing regulations.  
61   
62  The substantive portion of this document consists of two sections.  The first is the General Section 
63  (Section IV), which contains information of a general nature relating to diagnostic x-ray equipment. 
64  The second is the Specific Section (Section V), which contains information specific to particular 
65  sections of the Performance Standards for diagnostic x-ray systems which can be found in 21 CFR 
66  1020.30 through 1020.33.  
67  This document addresses only the requirements that apply to diagnostic x-ray equipment under the 
68  EPRC provisions of the FD&C Act and the regulations implementing those provisions.  This 
69  document does not address requirements that may apply to such equipment as medical devices 
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70  under provisions of the FD&C Act and its implementing regulations.  For more information on the 
71  regulation of diagnostic x-ray systems as a medical device, see FDAs website.3 
72  Manufacturers of diagnostic x-ray systems should be aware that CDRH intends to amend FDAs 
73  Performance Standards, as appropriate, to harmonize many of its requirements with those of the 
74  International Electrotechnical Commission (IEC) standards because FDA acknowledges the 
75  importance of simplifying compliance for global manufacturers.  Manufacturers are advised to 
76  regularly check the FDA website for new developments on this topic.4 
77  IV. General Information for Manufacturers of Diagnostic 
X-Ray Equipment 
78 
79   
80  Section 531 of the FD&C Act (21 U.S.C.  360hh) and implementing regulations in 21 CFR 
81  1000.3(d) define commerce as: 
82  a.  commerce between any place in any State and any place outside thereof, and 
83  b.  commerce wholly within the District of Columbia. 
84   
85  Section 538(a)(1) of the FD&C Act (21 U.S.C.  360oo) prohibits manufacturers from introducing, 
86  or delivering for introduction, into commerce any electronic product which does not comply with 
87  an applicable standard prescribed pursuant to Section 534 of the FD&C Act.  FDAs policy 
88  regarding the introduction of an electronic product into commerce within the meaning of Section 
89  538(a)(1) of the FD&C Act (21 U.S.C.  360oo) is discussed in Compliance Policy Guide 390.100.5 
90  As part of the requirements under the Radiological Health Regulations, manufacturers (as defined 
91  in 21 CFR 1000.3(n)) of diagnostic x-ray equipment which is intended for use on human patients 
92  must maintain records and provide reports to FDA (21 CFR Part 1002).  These records and reports 
93  support the manufacturers certification that their electronic products comply with all applicable 
94  requirements in the Performance Standards (see 21 CFR 1010.2). Manufacturers of diagnostic x-ray 
95  equipment must also include a label or tag permanently affixed to their electronic products that 
96  identify the manufacturer, location, and date of manufacture and state that the products are certified 
97  as meeting the requirements of the Performance Standards (see 21 CFR 1010.2 and 1010.3). Many 
98  diagnostic x-ray systems (as defined in 21 CFR 1020.30(b)) consist of components from different 
99  manufacturers; other systems use components from a single manufacturer.  In either case, 
100  compliance with the Performance Standards is dependent upon proper installation and final testing 
101  of the complete system at the user location.  
102  To allow for faster review, all required information, reports, and other submitted documentation to 
103  FDA should be written in the English language or accompanied by a complete English translation. 
                                                 
3 http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/Overview/default.htm 
4 http://www.fda.gov/Radiation-EmittingProducts/default.htm 
5 https://www.fda.gov/downloads/ICECI/ComplianceManuals/CompliancePolicyGuidanceManual/UCM337932.pdf 
 
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104  Additional information in question and answer format regarding assembler responsibilities is  
105  provided in FDAs guidance entitled, Guidance for Industry and Food and Drug Administration 
106  Staff - Assemblers Guide to Diagnostic X-Ray Equipment.6 
107  In general, under the Performance Standards, manufacturers of diagnostic x-ray equipment must: 
108    Certify that each component complies with the applicable Performance Standards. 
109  Certification of compliance means the manufacturer guarantees the component will 
110  perform as required by the Performance Standards when it is assembled, installed, 
111  adjusted, tested, and maintained in accordance with the manufacturer's instructions (21 
112  CFR 1020.30(c), 1020.30(g), 1020.30(h)(1)(ii)).  
113   
114    Permanently inscribe or affix certification and identification labels on the component or 
115  system (as applicable) complete with the name and address of the manufacturer, date and 
116  place of manufacture, model designation, and serial number on each component (21 CFR 
117  1010.3 and 1020.30(e)).  
118   
119    Provide the assembler, and others who request it, at a cost not to exceed the cost of 
120  publication and distribution, with adequate instructions for assembly, installation, 
121  adjustment, and testing of the component to assure the product will comply with the 
122  Performance Standards when the instructions are followed (21 CFR 1020.30(g)). The 
123  instructions must also provide specifications for other components that are compatible with 
124  the component to be installed when compliance of the component or system depends on 
125  such compatibility. The specifications may describe physical characteristics of compatible 
126  components and/or may list, by manufacturer's name and model designation, specific 
127  components that are compatible (21 CFR 1020.30(c) and 1020.30(g)).  
128   
129    Provide the purchaser with adequate instructions describing specific technical specifications 
130  of the equipment and any necessary radiological safety precautions and procedures which 
131  may be necessary because of unique features of the equipment as well as a schedule of the 
132  maintenance necessary to keep the equipment in compliance with the Performance 
133  Standards (21 CFR 1020.30(h)(1)). 
134   
135  V. Specific Topics of Importance to Manufacturers of 
Diagnostic X-Ray Equipment 
136 
137   
138  A. Introduction into Commerce and Certification (see also questions 
139  37, 38, 88, 92, 93, 96, 97, and 98) 
140   
                                                 
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141  The certification process for diagnostic x-ray equipment is a component-by-component process.  
142  21 CFR 1020.30(a)(1)(i) identifies the certifiable components of a diagnostic x-ray system 
143  (referred to in this guidance, as diagnostic x-ray components). These diagnostic x-ray 
144  components may also qualify as medical devices under section 201(h) of the FD&C Act (21 
145  U.S.C. 321(h)) and are also subject to the provisions of the FD&C Act that apply to medical 
146  devices.  The component by itself may not be able to produce diagnostic x-rays, but is intended 
147  to be installed or assembled with other compatible components into a complete diagnostic x-ray 
148  system at the user location.   
149   
150  1.  QUESTION:  When is a diagnostic x-ray component or system considered to have been 
151  introduced into commerce? 
152   
153  ANSWER:  See the discussion of introduction into commerce provided in this guidance in 
154  Section IV - General Information for Manufacturers of Diagnostic X-Ray Equipment.  As stated 
155  in the Compliance Policy Guide Sec. 390.100, if a diagnostic x-ray component or system 
156  intended for human use has been offered for sale or assembled by a person engaged in the 
157  business of assembling that product, FDA considers the component or system to have been 
158  introduced into commerce.7   
159    
160  2.  QUESTION:  Must an electronic product be certified before introduction into commerce? 
161   
162  ANSWER:  Yes.  Section 538(a)(1) of the FD&C Act (21 U.S.C. 360oo) prohibits the 
163  introduction into commerce of any electronic product which does not comply with an applicable 
164  standard prescribed pursuant to section 534 of the FD&C Act (21 U.S.C.  360kk), and section 
165  534(h) of the FD&C Act requires every manufacturer of an electronic product to furnish, to the 
166  dealer or distributor at the time of delivery, a certification the product conforms to all applicable 
167  standards.  Consequently, any diagnostic x-ray component or system introduced into commerce 
168  for use on human subjects must be certified to comply with the applicable Performance 
169  Standards before it is introduced into commerce (see also Section 534(a)(1) of the FD&C Act 
170  (21 U.S.C.  360kk(a)(1))).   
171    
172  3.  QUESTION:  If a diagnostic x-ray system has been installed for use under an investigational 
173  device exemption (IDE), must it be certified?   
174   
175  ANSWER:  Yes.  If a diagnostic x-ray component or system has been assembled for use on 
176  humans, including installation for use under an IDE (see Section 520(g) of the FD&C Act (21 
177  U.S.C. 360j(g)) and 21 CFR part 812), it has been introduced into commerce and must both 
178  comply with all applicable standards prescribed pursuant to section 534 of the FD&C Act (21 
179  U.SC.  360kk) prior to introduction, and be certified (Sections 538(a)(1) and (5) of the FD&C 
180  Act (21 U.S.C.  360oo(a)(1) and (5))).   
181   
182  4.  QUESTION:  After a diagnostic x-ray system or component has been sold and installed, who is 
183  responsible for ensuring continued equipment compliance with the Performance Standards? 
                                                 
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184   
185  ANSWER:  The certifying manufacturer is responsible for designing systems and 
186  components to guarantee compliance with the Performance Standards for the life of the 
187  equipment when the equipment is properly maintained (21 CFR 1020.30(c)).  A certified 
188  product that is maintained according to the maintenance schedule provided by the certifying 
189  manufacturer is expected to conform to the regulations and Performance Standards in effect 
190  on the date of manufacture (e.g., 21 CFR 1020.30(c) and 1020.30(h)).  If evaluated today, for 
191  example, a product manufactured in 2004 is expected to be in compliance with the 
192  regulations in effect in 2004.   
193   
194  Because diagnostic x-ray equipment usually will remain in use for many years, the certifying 
195  manufacturer is required to provide a maintenance schedule that, if properly implemented by 
196  the user, will keep the equipment in compliance with the Performance Standards (21 CFR 
197  1020.30(h)(1)(ii)).  If the assembler installs the equipment following the instructions 
198  provided by the certifying manufacturer (21 CFR 1020.30(g)), and the user maintains the 
199  equipment according to the maintenance schedule provided by the certifying manufacturer 
200  (21 CFR 1020.30(h)(1)(ii)), the certifying manufacturer may be held responsible for 
201  manufacturer-related compliance issues until the equipment is permanently removed from 
202  service.  However, the certifying manufacturer will not be held responsible for incorrect 
203  installations, incorrect repairs, or failure by other firms or the user to maintain the system 
204  properly (21 CFR 1020.30(c)). 
205   
206  5.  QUESTION:  A firm manufactures x-ray equipment for use in veterinary offices, pathology 
207  laboratories, and for training radiologic technologists when no human subjects are involved.  
208  Must this equipment be certified?  Is the firm required to file a Form FDA 2579 (Report of 
209  Assembly of a Diagnostic X-Ray System)? 
210   
211  ANSWER:  No to both questions.  A diagnostic x-ray system is defined, for the purposes of 
212  the Performance Standards, as an x-ray system designed for irradiation of any part of the 
213  human body for the purpose of diagnosis or visualization (21 CFR 1020.30(b)).  Because the 
214  electronic products are not intended for use on humans, they do not need to be certified.  
215  However, these systems are considered electronic products under 21 CFR Subchapter J, and the 
216  firm must comply with all of the electronic product radiation control requirements for 
217  equipment without a specific performance standard (21 CFR 1002.1(b)).  This includes any 
218  reporting requirements in Table 1 of 21 CFR 1002.1 and reporting accidental radiation 
219  occurrences (AROs) to the FDA. 
220   
221  The firm is not required to file Form FDA 2579.  Form FDA 2579 is filed to report assembly of 
222  certified diagnostic equipment intended for irradiation of any part of the human body for the 
223  purpose of diagnosis or visualization.  The completion and filing of the form is not required for 
224  any non-human application.  Even though certified equipment is often installed in veterinary 
225  facilities, when such equipment will be used as dedicated veterinary equipment, it does not 
226  require certification to the Performance Standards.   
227   
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228  Note:  Some state and local agencies may have more stringent reporting requirements, and the 
229  firm should check with them regarding their requirements.   
230   
231  6.  QUESTION:  Are there specific requirements for diagnostic x-ray systems installed in mobile 
232  vehicles? 
233   
234  ANSWER:  No.  There are no specific requirements in 21 CFR 1020.30 for diagnostic x-ray 
235  systems installed in mobile vehicles.  However, imaging systems installed in mobile vehicles 
236  may be subjected to adverse environmental conditions that do not occur in unmoving 
237  installations.  FDA recommends that manufacturers provide specific instructions for assembly, 
238  testing, and maintenance of systems that are designed for, or routinely installed in, mobile 
239  vehicles that account for these adverse environmental conditions.  
240   
241  NOTE:  Stationary systems installed in mobile vehicles are bound by the requirements for 
242  stationary systems provided in the Performance Standards. 
243   
244  7.  QUESTION:  If a component is designed or modified so that it performs a function that is 
245  characteristic of a certifiable component, does it need to be certified with respect to that 
246  function?  
247   
248  ANSWER:  Yes.  Any system, subsystem, or component that serves substantially the same 
249  function (i.e., performs the same function) as a certified component (see 21 CFR 1002.1 and 21 
250  CFR 1020.30(a)) meets the definition of that component and therefore must be certified (21 
251  CFR 1020.30(c)). 
252   
253  For example, if software included with a digital detector controls the technique factors (e.g., 
254  duration of an exposure), then the software performs the same function as an x-ray control and 
255  therefore is itself an x-ray control.  Because an x-ray control is a certifiable component, the 
256  software is subject to the requirements of the Performance Standards relevant to x-ray controls.  
257  These requirements include a statement of compatibility with other components in the system 
258  (21 CFR 1020.30(g)). 
259   
260  Also, if the detector is marketed with a front panel (dust cover, etc.) that is not necessary for the 
261  digital detectors operation, the front panel performs the same function as a cassette holder with 
262  front panel.  Because a cassette holder with front panel is a certifiable component (see 21 CFR 
263  1020.30(a)(i)(A)), the front panel is subject to the requirements of the Performance Standards 
264  relevant to cassette holders with front panels.  These requirements include maximum aluminum 
265  equivalence requirements under 21 CFR 1020.30(n) and the front panel must be certified as a 
266  cassette holder with front panel (21 CFR 1020.30(c)).   
267   
268  These are examples and not an exhaustive discussion.  For questions related to other design 
269  features, please contact the FDA. 
270   
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271  Note that adding functionality to a device may affect labeling applied to a component or 
272  subsystem.  See the questions and answers in the General Labeling section below for more 
273  information on labeling requirements for various components and systems. 
274   
275  8.  QUESTION:  Must each manufacturer of certifiable components provide information regarding 
276  the compatibility of their products with other components? 
277   
278  ANSWER:  Manufacturers of certified components or systems must provide information to 
279  assemblers, purchasers and others who request it, at a cost not to exceed the cost of publication 
280  and distribution, including instructions for assembly, installation, adjustment, and testing (21 
281  CFR 1020.30(g) and 1020.30(h)).  When compliance of the component(s) or system depends on 
282  component compatibility, the information provided must include specifications of compatible 
283  components (21 CFR 1020.30(g)).  Such specifications may describe pertinent physical 
284  characteristics of the components and/or may list by manufacturer model number the 
285  components that are compatible.  While it is permissible to list manufacturer model numbers to 
286  specify compatible components, that is not the only acceptable means for identifying 
287  compatible components.  A manufacturer may also describe pertinent physical characteristics of 
288  the components to identify those which are compatible.  However, manufacturers are not 
289  required to disclose trade secrets or confidential information. 
290   
291  9.   QUESTION:  Are cone-beam x-ray systems required to conform to the Computed Tomography  
292  (CT) performance standard (21 CFR 1020.33) even though certain sections dont seem 
293  appropriate for cone-bean technology? 
294   
295  ANSWER:  Dental cone-beam computed tomography (CBCT) devices are considered 
296  Computed Tomography systems because they depict the x-ray attenuation properties of a 
297  section through the body by the acquisition and computer processing of x-ray transmission data.  
298  They are therefore subject to the CT performance standard under 21 CFR 1020.33, including 
299  but not limited to the quality assurance requirements provided in 21 CFR 1020.33(d).  If one or 
300  more provisions of the CT performance standard under 21 CFR 1020.33 do not appear 
301  appropriate for a CBCT device, the manufacturer should apply for a variance from such 
302  provision(s) as described in 21 CFR 1010.4. 
303   
304  B. Labeling (see also questions 45, 79, 99, and 100) 
305   
306  (1)  General Labeling 
307   
308  10. QUESTION:  Must labels be written in the English language? 
309   
310  ANSWER:  Yes.  All required labels must be written in the English language (21 CFR 
311  1010.2(b) and 1010.3(a)), with the exception of foreign equivalents to abbreviations such as 
312  Co., and Inc. (21 CFR 1010.3(a)(1)). 
313   
314  11. QUESTION:  A firm sells diagnostic x-ray systems, all of which consist of the same 
315  combination of components.  May the firm place the certification and identification information 
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316  for the system, with specific component information (e.g., model number, serial number, and 
317  date of manufacture), in the users manual rather than on the individual components? 
318   
319  ANSWER:  No.  The required labeling must be placed on each component or subsystem subject 
320  to certification (21 CFR 1010.2, 1010.3 and 1020.30(c)). 
321   
322  12. QUESTION:  May a combination of certifiable diagnostic x-ray products be identified with a 
323  single certification label and a single identification label? 
324   
325  ANSWER:  Yes, under the following circumstances, combinations of certified components may 
326  be labeled together: 
327   
328  a.  high-voltage generators (HVG) contained within tube housing assemblies (THA), 
329  b.  beam-limiting devices (BLD) that are integral parts of THAs, 
330  c.  HVGs and x-ray controls when inseparable, combined in a single housing, and marketed 
331  under a single model designation, 
332  d.  combinations of components with written approval to single-label a specific 
333  combination of components (21 CFR 1020.30(c)), or 
334  e.  combinations of components where written approval of an alternate means of labeling 
335  (21 CFR 1010.3(b)) permits single labeling of that combination of components. 
336   
337  13. QUESTION:  How should a manufacturer apply for FDA authorization to single label 
338  combinations of certifiable components not covered above in question 12? 
339   
340  ANSWER:  A written request must be submitted to FDA as required by 21 CFR 1020.30(c).  
341  The written request should specify the components to be single labeled and include the reasons 
342  why the manufacturer believes the labeling request should be authorized.  
343   
344  Manufacturers interested in requesting permission to single label a combination of components 
345  should send their requests to the attention of the Director Center for Devices and Radiological 
346  Health, Food and Drug Administration, 10903 New Hampshire Avenue, Bldg. 66, Silver 
347  Spring, MD 20993-0002. 
348   
349  14. QUESTION:  How will FDA evaluate requests submitted pursuant to 21 CFR 1020.30(c) to 
350  certify single label combinations of certifiable components?  
351   
352  ANSWER:  The manufacturer must demonstrate that the combination of certifiable components 
353  is compliant with the applicable Performance Standards under a testing program (see 21 CFR 
354  1010.2(c)) for the single label to denote product certification.  Each request will be evaluated on 
355  a case-by-case basis, but the certifiable components should be contained in a single housing and 
356  marketed as a single certified entity, except for repair parts. 
357   
358  15. QUESTION:  Items such as phototimers, automatic exposure controls, and positive beam 
359  limiting systems (including collimator, sensing tray, and electrical chassis), are made up of 
360  subassemblies located in various parts of the system, including in or on other certifiable 
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361  components.  Must each of these subassemblies be labeled with manufacturer identification, 
362  model, and certification information as specified in 21 CFR 1010.3 and 1020.30(e), or may one 
363  model number be assigned to the multiple parts? 
364   
365  ANSWER:  Assignment of more than one model number and nameplate to the scattered parts of 
366  certifiable components is permissible but it is not required.  FDA does not intend to object if 
367  only the essential part(s) of a certifiable component are labeled as specified under 21 CFR 
368  1010.3 and 1020.30(e).   
369   
370  16. QUESTION:  The use of laptop computers or desktop computers with off-the-shelf monitors 
371  that have software loaded to control diagnostic x-ray systems has become widespread.  Are both 
372  the original and replacement computers required to be labeled with identification, certification, 
373  and warning labels? 
374   
375  ANSWER:  Yes. We consider software that controls a diagnostic x-ray system loaded on a 
376  laptop or desktop computer to serve the same function as an x-ray control and to be subject to 
377  the same labeling requirements as any other diagnostic x-ray control as described in 21 CFR 
378  1020.30(b).   
379   
380  The manufacturer of such diagnostic x-ray system control software may state that a personal 
381  computer and/or monitor meets their compatibility criteria.  However, once a user installs a 
382  personal computer or monitor, which meets the x-ray system control software manufacturers 
383  statement of compatibility, into a completed diagnostic x-ray system, the diagnostic x-ray 
384  system control software manufacturer continues to be responsible for compliance with the 
385  applicable requirements, and management of the risks of the x-ray control aspects of the 
386  diagnostic x-ray system. 
387   
388  The replacement of a diagnostic x-ray system controls monitor by a user may affect the 
389  components compliance with applicable labeling requirements.  The certification and 
390  identification labels (or the display of their contents) must be readily accessible by the user (see 
391  21 CFR 1010.2 and 1010.3) and the required warning statement must be displayed on each 
392  computer and/or monitor used as a control panel (21 CFR 1020.30(j)).  The labeling 
393  requirements for personal computers and/or monitors used as x-ray controls may be satisfied in 
394  several ways. Two examples of labeling methods that would satisfy this requirement are: 
395   
396    Physical labels consistent with 21 CFR 1010.2, 1010.3, and 1020.30(j), accompanied by  
397  adequate instructions for placement and verification of the labels.   
398   
399    Alternatively, FDA does not intend to object where these labels are displayed 
400  electronically as long as: 
401    Each time the system is started, the screen displays the approved certification and 
o
402  identification labels; and 
403    During use, the required warning label is continuously displayed on the screen.  If 
o
404  the screen is used as both an acquisition and review work station, the warning 
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405  need not be displayed when in the review mode, but must be continuously 
406  displayed when in the acquisition mode. 
407   
408  17.  QUESTION:  Device labeling regulations under 21 CFR 801 and 809 generally permit the use  
409  of symbols in device labeling without adjacent explanatory text if certain requirements are met.8 
410  Is this use of symbols found in standards such as ISO 7000 permitted in the mandatory labeling 
411  for certified x-ray components required by 21 CFR 1010.3(e) and 21 CFR 1020.30(e)? 
412   
413  ANSWER:  Yes.  FDA does not intend to object to the use of certain symbols in the labeling 
414  required by 21 CFR 1020.30 consistent with the device labeling regulations under 21 CFR 801 
415  and 809. 
416   
417  For instance, certain FDA-recognized standards such as ISO 7000: Graphical symbols for use 
418  on equipment and IEC 60417: Graphical symbols for use on equipment include symbols which 
419  FDA does not intend to object to when used on labels required by the Performance Standards. 
420  Some examples of permissible symbols from ISO 7000:2014 include catalogue number, serial 
421  number, and date of manufacture.  
422   
423  Because other required labels, including the certification label (21 CFR 1010.2) and warning 
424  label (21 CFR 1020.30(j)), require complete phrases written in English and cannot be 
425  adequately represented by symbols, symbols may not be used in those labels. 
426   
427  (2)  Label Location  
428   
429  19. QUESTION:  Items such as phototimers, automatic exposure controls, and positive beam 
430  limiting systems (including collimator, sensing tray, and electrical chassis), are made up of 
431  subassemblies located in various parts of the system including in or on other certifiable 
432  components.  It is understood that FDA considers it reasonable to label only the essential part(s) 
433  of a major component (see question 15).  Where should such labels be located?  
434   
435  ANSWER:  Table 1 below lists several major components and suggested label locations for 
436  each major component.  If you have received written authorization from FDA (21 CFR 
437  1020.30(c)) to sell two or more major components as a single-labeled device (i.e., one catalog 
438  item that is not intended to be subdivided for use with other components), only one label is 
439  required.   
440   
441  NOTE: All tube housing assemblies must be labeled with the name of the manufacturer, model 
442  number, and serial number of the x-ray tube which the tube housing assembly incorporates, 
443  since they are subject to frequent replacement (21 CFR 1020.30(e)(1)). 
444   
445   
446   
447   
                                                 
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448  Table 1.  Suggested Label Locations for Major Components 
449   
Major Component  Label Location 
Tube Housing Assembly  On housing, including under-table tubes 
X-ray Control  On each x-ray control panel and control 
electronics cabinet 
X-ray HV Generator  On generator housing 
Fluoroscopic Imaging Assembly  On spot film device and image intensifiers 
Table  On each table 
Cradle  On each cradle 
Film Changer  On changer (if separate control unit is 
provided, this must also be labeled) 
Cassette Holder  On each cassette holder 
Beam Limiting Device  On outside of each collimator 
450   
451  20. QUESTION:  What is FDAs policy concerning the location of the certification and 
452  identification labels and the warning label for diagnostic x-ray systems?  
453   
454  ANSWER:  Identification and certification labels must be legible and readily accessible to view 
455  when the product is fully assembled for use (21 CFR 1010.2(b) and 1010.3(a)).  FDA interprets 
456  legible and accessible to view for diagnostic x-ray systems to be a location where a person 
457  can read the label without having to relocate the x-ray system or use a tool to remove or open 
458  panels, doors, etc.  The identification and certification labels should be on the outside of the 
459  equipment and not on a side that is normally placed against a wall.  For some components, such 
460  as a tube housing assembly mounted under a table, the identification and certification labels 
461  may not be visible from outside the completed system.  In such a case, the identification and 
462  certification labels should be mounted on the component, although the component itself is not 
463  visible.  If the identification or certification label is behind a door, panel, under a table, etc., in a 
464  location that is readily accessible without the need to unbolt, unlock, or relocate the x-ray 
465  system, wording should appear on the door, panel, etc., indicating the location of the 
466  identification and/or certification labels.  (See 21 CFR 1010.2 and 1010.3 regarding general 
467  label requirements.)  
468   
469  The warning label serves to alert users to the hazards associated with the use of the equipment 
470  and, by its nature, should be conspicuous to the user.  It should be situated so that a user of an x-
471  ray machine can see the warning when he/she is preparing to initiate an exposure (21 CFR 
472  1020.30(j)).  To be consistent with the intent of the regulation, there should be a warning label 
473  visible at each location where technique factors may be set and/or where x-ray exposure may be 
474  initiated.   
475   
476  21. QUESTION:  For aesthetic reasons, some manufacturers place certified components behind 
477  cosmetic covers and then place duplicate certification and identification labels on the covers.  Is 
478  this acceptable? 
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479   
480  ANSWER:  Yes, but only where the components themselves are also appropriately labeled.  
481  FDA considers this duplicate label placement to satisfy the accessible to view requirements of 
482  the Performance Standards (21 CFR 1010.2(b) and 1010.3(a)), as long as the manufacturer 
483  provides adequate assembly instructions to verify that the component label and the duplicate 
484  label on the outside casing are identical.  The placement of the duplicate label(s) should be on 
485  the covering over the certified component and not at another location removed from the 
486  component itself.  Manufacturers who wish to use such alternative labeling should notify FDA 
487  in their product reports (21 CFR 1002.10(j)) and provide copies of the assembly instructions 
488  that address proper label placement.  This labeling scheme can cause problems when component 
489  replacement is necessary.  The assembly instructions provided with replacement components 
490  should address this issue. 
491   
492  22. QUESTION:  A firm manufactures fluoroscopic systems used for angiography and 
493  interventional procedures.  The diagnostic source assembly (DSA) is covered by a plastic 
494  shield.  The shield makes cleaning of the DSA easier.  The certification and identification labels 
495  on the tube housing assembly and beam limiting device are covered by the shield.  There is a 
496  panel on the shield that can be removed with a screwdriver that would allow access to the 
497  certification and identification labels if needed.  Is this acceptable? 
498   
499  ANSWER:  No.  Because the panel requires a screwdriver to open, the labels are not considered 
500  accessible to view.  Since the certification and identification labels are not accessible to view 
501  under normal use (21 CFR 1010.2(b), 1010.3(a), and 1020.30(e)), this is not acceptable and 
502  would not comply with the regulations.  Acceptable solutions may include designing the panel 
503  to be removable without the use of tools, placing the labels behind a clear shield so that they 
504  remain accessible to view, or designing robust labels such that their information remains legible 
505  despite cleaning practices and placing them without the protective shield. 
506   
507  23. QUESTION:  A firm has been asked to install a diagnostic x-ray system in a facility where a 
508  wall will prevent anyone from seeing the certification and identification labels on the x-ray 
509  table.  Is this acceptable? 
510   
511  ANSWER:  No.  Even if the x-ray table was otherwise properly labeled, the proposed 
512  placement would render the assembly noncompliant (21 CFR 1010.2(b), 1010.3(a), and 
513  1020.30(e)) because the labels will not be accessible to view. 
514   
515  24. QUESTION:  Sections 21 CFR 1020.30(c) and 21 CFR 1020.30(e) require that labels be 
516  accessible to view when the equipment is installed.  Since the installation of equipment is 
517  frequently performed by personnel other than manufacturer representatives, how can the 
518  manufacturer assure label visibility after assembly? 
519   
520  ANSWER:  The manufacturer must provide instructions to the assembler regarding proper 
521  placement of components so that the labels are visible and accessible when the installation is 
522  completed to assure the equipment complies with the regulations (21 CFR 1020.30(g)).   
523   
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524  (3)  Certification Labels 
525   
526  21 CFR 1010.2(a) requires every manufacturer of an electronic product for which an applicable 
527  standard is in effect to furnish to the dealer or distributor, at the time of delivery, the certification 
528  that such product conforms to all applicable Performance Standards unless FDA has approved an 
529  alternate means to provide certification (21 CFR 1010.2(d)).  Such certification must be in the form 
530  of a label or tag permanently affixed to or inscribed on such product so as to be legible and readily 
531  accessible to view when the product is fully assembled for use (21 CFR 1010.2(b)).  Each 
532  certifiable component of a diagnostic x-ray system must have its own certification label unless the 
533  system falls under the provisions for single labeling (21 CFR 1020.30(e)).  Single labeling 
534  questions and answers are provided in the Section General Labeling above. 
535   
536  25. QUESTION:  Is there specific wording required to meet the certification labeling requirement 
537  in 21 CFR 1010.2(a)? 
538   
539  ANSWER:  No.  The regulation concerning certification (21 CFR 1010.2(a)) does not specify 
540  the wording of the certification label; it states that Every manufacturer of an electronic product 
541  for which an applicable standard is in effect under this subchapter shall furnish to the dealer or 
542  distributor, at the time of delivery of such product, the certification that such product conforms 
543  to all applicable standards under this subchapter. 
544   
545  Two examples of suggested wording that satisfy 21 CFR 1010.2(a) include: 
546   
547    Complies with DHHS radiation performance standards, 21 CFR Subchapter J 
548    Product complies with applicable DHHS standards under Subchapter C - Electronic 
549  Product Radiation Control of Chapter V of the Federal Food, Drug and Cosmetic Act. 
550   
551  26. QUESTION:  May a manufacturer use the words at the time of manufacture in the 
552  certification label to indicate that the certification statement applies to the regulations in effect 
553  at the time of manufacture? 
554   
555  ANSWER:  Yes, if the phrase is qualified appropriately.  Some manufacturers use the term at 
556  the time of manufacture in their certification statement because the regulations are amended 
557  from time to time.  However, the addition of this phrase can cause some confusion as to whether 
558  it refers to compliance or to the regulation.   
559   
560  If the phrase at the time of manufacture is placed on the certification label then the words in 
561  effect or applicable should be included with the phrase to clearly indicate that the 
562  certification statement means that the component complies with the regulations in effect at the 
563  time of manufacture.  Two examples of acceptable wording are: 
564   
565    Complies with DHHS radiation performance standards, 21 CFR Subchapter J, in effect 
566  at time of manufacture.; or 
567   
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568    Product complies with applicable DHHS standards in effect at time of manufacture 
569  under Subchapter C - Electronic Product Radiation Control of Chapter V of the Federal 
570  Food, Drug and Cosmetic Act. 
571   
572  27. QUESTION:  Since shipping containers of components being imported into the U.S. are 
573  typically not opened at the time of customs inspection, is any certification labeling required on 
574  the outside of these shipping containers?  
575   
576  ANSWER:  No.  However, the importer must file a declaration (Form FDA 2877) upon entry of 
577  the product into the U.S. (19 CFR 12.91(b)).  
578   
579  (4)  Identification Labels 
580   
581  28. QUESTION:  How should the manufacturer be identified on component identification labels? 
582   
583  ANSWER:  21 CFR 1010.3(a)(1) requires that the full name and address (in English) of the 
584  certifying manufacturer be stated on each certifiable component, in the form of a label or tag 
585  permanently affixed to or inscribed on the product.  Under the EPRC provisions of the FD&C 
586  Act, the certifying firm (whether manufacturer, importer or assembler) is the responsible 
587  manufacturer for compliance of the certified component.   
588   
589  If the product is sold under a label other than that of the certifying manufacturer, the full name 
590  and address of the selling individual or company may be placed on the label as the manufacturer 
591  as long as prior to introduction of the product into commerce, the CDRH Director has been 
592  provided sufficient information to identify the manufacturer of the product (21 CFR 
593  1010.3(a)(1)).  This label must also contain the date of manufacture of the component (21 CFR 
594  1010.3(a)(2)).  Labels on certified components that are medical devices must contain the phrase 
595  Manufactured for ___, or Distributed by ___ (or other wording that expresses the facts) 
596  when the device is sold under a label other than that of the component manufacturers label (21 
597  CFR 801.1(c)).   
598   
599  29. QUESTION:  Under 21 CFR 1010.3(a)(2)(ii), the format for the date of manufacture is 
600  Manufactured: (Insert Month and Year of Manufacture).  May manufacturers use other 
601  formats instead, such as 12/2/2009, 2-Dec-09, or 2009-12-02?  May they use Date of 
602  Manufacture: instead of Manufactured:? 
603   
604  ANSWER:  The regulation specifies the format for the date of manufacture (21 CFR 
605  1010.3(a)(2)(ii)).  This format may not be modified.  The month and year of manufacture must 
606  be provided clearly and legibly, as follows: 
607   
608  MANUFACTURED: (INSERT MONTH AND YEAR OF MANUFACTURE) 
609   
610  The date of manufacture must have the month spelled out, and the year as a four-digit number 
611  (Example: December 2009) (21 CFR 1010.3(a)(2)(ii)).  Manufacturers may add the actual date 
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612  of manufacture, as long as the correct month and year format is used (Example: 
613  MANUFACTURED:  December 2, 2009).   
614   
615  FDA does not intend to object to the formats DATE OF MANUFACTURE, DATE 
616  MANUFACTURED, and MANUFACTURED DATE. 
617   
618  30. QUESTION:  What is the place of manufacture as used in 21 CFR 1010.3? 
619   
620  ANSWER:  The place of manufacture is the location where the certifiable component or system 
621  is produced.  A code may be used to identify the place of manufacture if the CDRH Director has 
622  previously been provided the key to such code (21 CFR 1010.3(a)(2)(i)).   
623   
624  31. QUESTION:  A firm manufactures diagnostic x-ray components and systems at several 
625  locations.  The firm would like to include its corporate office name and address on the 
626  identification label.  Is the firm required to also identify the place of manufacture?  May it use a 
627  code on the label to identify the place of manufacture?
 
628   
629  ANSWER:  Yes to both questions.  The firm is required to identify the place of manufacture (21 
630  CFR 1010.3(a)(2)).  It may use a code to identify the place of manufacture, provided that it has 
631  supplied FDA with a listing of the codes, along with the name and address of the place of 
632  manufacture associated with each code (21 CFR 1010.3(a)).  See also question 28. 
633   
634  32. QUESTION:  It is understood that 21 CFR 1010.3(a)(1) and (2) require that manufacturers 
635  include their full name, address and place of manufacture on their electronic product 
636  identification tags or labels.  May a manufacturer place its Uniform Resource Locator (URL) on 
637  its electronic product labels instead? 
638   
639  ANSWER:  No.  The Performance Standards do not permit manufactures to place the URL 
640  information on a label instead of the specified information.  The product label must include 
641  the information required in the regulations (21 CFR 1010.3(a)(1) and (2)).   
642   
643  However, as discussed in FDAs guidance entitled Guidance for Industry and FDA Staff - 
644  Addition of URLs to Electronic Product Labeling,9 FDA recommends, when feasible, that 
645  manufacturers add their URL to their electronic product tag or label, in addition to the 
646  identification information required under 21 CFR 1010.3(a)(1) and (2). 
647   
648  33. QUESTION:  21 CFR 1020.30(e) requires manufacturers of diagnostic x-ray  
649  components that are subject to the Performance Standards to permanently inscribe or affix to 
650  each component the model number and serial number (identification labels) of the 
651  component.  How does the FDA interpret this requirement?  
652   
                                                 
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653  ANSWER:  21 CFR 1020.30(e) specifies that a model number and serial number shall be 
654  inscribed or affixed to a component, and that the word model or type shall appear as part of 
655  the manufacturers required identification of certified x-ray components.  A model designation 
656  should describe only one certified component, and it should not be used to describe an 
657  assemblage of components except as specified in 21 CFR 1020.30(e) or as specifically 
658  authorized by the FDA.  See also question 13. 
659   
660  34. QUESTION:  Is specific wording required to meet the labeling requirement for specific 
661  component identification? 
662   
663  ANSWER:  Yes, in addition to the identification requirements of 21 CFR 1010.3, 21 CFR 
664  1020.30(e) describes additional identification labeling requirements for major components of 
665  diagnostic x-ray system by specifying the listing of model and serial numbers.  The specified 
666  format calls for the word model or type to appear on the label.  Tube housing assemblies 
667  require additional information on their identification label.  The name of manufacturer, the 
668  model number, and the serial number of the tube insert must also appear on the identification 
669  label (21 CFR 1020.30(e)(1)).  The reloading of the tube insert in a previously certified tube 
670  housing assembly constitutes manufacture of a new tube housing assembly; this requires the 
671  manufacturer to remove, cover, or deface any previously affixed tube insert inscriptions, tags, or 
672  labels that are no longer applicable and apply new tube insert labels (21 CFR 1020.30(e)(2)). 
673   
674  (5)  Warning Labels 
675   
676  The control panel is the means used by the operator to set technique factors (21 CFR 1020.30(b)).  
677  The prescribed warning statement must be present on the control panel, and this label must be 
678  legible and accessible to view and should be viewable by the operator during adjustment of 
679  technique factors (21 CFR 1020.30(j)) (see question 20).  The control panel may be physically co-
680  located with the control (i.e., mounted directly to the cabinet) or separated from the control (i.e., a 
681  satellite or remote panel).  The control panel may consist of a single operator interface or multiple 
682  operator interfaces.   
683  35. QUESTION:  Has the wording for the warning label (21 CFR 1020.30(j)) on the control panel 
684  changed as a result of the June 10, 2006 amendments to the Performance Standard? 
685   
686  ANSWER:  Yes.  The change adds maintenance schedules to the required wording of the 
687  warning label as prescribed in 21 CFR 1020.30(j) as follows: 
688   
689  a.  New controls manufactured on or after June 10, 2006: 
690   
691    Warning: This x-ray unit may be dangerous to patient and operator unless safe 
692  exposure factors, operating instructions and maintenance schedules are observed. 
693   
694   
695   
696   
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697  b.  Old controls manufactured prior to June 10, 2006:  
698   
699  Warning: This x-ray unit may be dangerous to patient and operator unless safe 
700  exposure factors and operating instructions are observed. 
701   
702  NOTE:  Warnings that differ slightly from the standard but are more forceful and restrictive in 
703  content meet the intent of the regulations.  However, it is important that each aspect of the 
704  warning label (i.e. safe exposure factors, operating instructions, and maintenance schedules) be 
705  addressed in the warning. 
706   
707  36. QUESTION:  21 CFR 1020.30(j) requires a warning label on the control panel.  Modern control 
708  panels may incorporate or be wholly replaced by a computer that serves as a user interface for 
709  purposes of adjusting technique factors and for the initiation of x-ray exposure.  Can a 
710  manufacturer propose to display the required warning statement on the computer monitor 
711  screen?   
712   
713  ANSWER:  Yes.  FDA acknowledges that the cited regulation does not specifically address 
714  computerized control of x-ray production.  However, we believe that the definition can be 
715  applied to controls and control panels utilizing a computer as a user interface.  
716   
717  Software may incorporate certification and identification statements within the code that are 
718  reflective of labels affixed to the x-ray control (e.g., on the electronics cabinet or operator 
719  console).  Software performing x-ray control functions should also incorporate a means to 
720  electronically display the required warning statement on each computer/terminal used as a 
721  control panel unless a permanent warning label is present.  See also question 20.   
722   
723  C. Date of Manufacture (See also question 29) 
724   
725  37. QUESTION:  Several of the applicable Performance Standards differ based on whether or not 
726  the equipment was manufactured before June 10, 2006.  How does a manufacturer determine if 
727  its system is required to comply with the updated Performance Standards? 
728   
729  ANSWER:  An x-ray system must comply with the revised performance standards that are in 
730  effect for equipment manufactured on or after June 10, 2006, when: 
731   
732  1)  The complete system is certified (21 CFR 1002.1 Table 1  Footnote 4) and the systems 
733  date of manufacture falls on or after June 10, 2006; or 
734   
735  2)  All of the certified components in the system were manufactured on or after June 10, 
736  2006, as provided by each of their identification labels. 
737   
738  Note that if a systems date of manufacture falls before June 10, 2006 and a certified component 
739  with a date of manufacture on or after June 10, 2006 is used to replace an existing component in 
740  this system, the new component must comply with the applicable revised performance 
741  standards; however the system is not required to comply with all of the revised performance 
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742  standards as a result of installing the single new certified component.  However, if a certified 
743  component with a date of manufacture before June 10, 2006, is installed into a certified system 
744  manufactured on or after June 10, 2006, then the system is still required to conform to all of the 
745  revised performance standards. 
746   
747  Example 1:  An air kerma display manufactured in 2007 could be used to replace an air 
748  kerma display on a fluoroscopic x-ray system manufactured in 2005.  This new air kerma 
749  display must be certified to conform to the performance standards applicable on its date of 
750  manufacture (ex., 21 CFR 1020.32(k)).  However, the fluoroscopic x-ray system would not 
751  be required to conform to other revised performance standards applicable on or after June 
752  10, 2006 as a result of installing the single new certified air kerma display. 
753   
754  Example 2:  A fluoroscopic x-ray system was manufactured in 2007 and certified as a 
755  system using a certified air kerma display which was manufactured in 2005.  Because the x-
756  ray system was certified as a system and the systems date of manufacture is in 2007, the 
757  system is still required to conform to all of the revised performance standards applicable on 
758  or after June 10, 2006 even though the revised performance standards didnt apply to the air 
759  kerma display as of its own date of manufacture. 
760   
761  For computerized tomography (CT) systems manufactured on or after September 3, 1985, the 
762  date of manufacture of the system is defined as the date of manufacture of the CT gantry as 
763  provided by the identification labeling (21 CFR 1020.30(a)(3)). 
764   
765  38. QUESTION:  When an existing diagnostic x-ray system is disassembled or removed from its 
766  original location and reassembled at a different location does its date of manufacture change? 
767   
768  ANSWER:  No.  A system that is disassembled and reassembled with the same components 
769  retains its previous date(s) of manufacture.   
770   
771  For additional information on assembly of diagnostic x-ray equipment, see FDAs guidance 
772  entitled Guidance for Industry and Food and Drug Administration Staff - Assemblers Guide to 
773  Diagnostic X-Ray Equipment.10 
774   
775  D. Measurements 
776   
777  39. QUESTION:  There are many references in 21 CFR Subchapter I to test methods used to 
778  determine compliance with the Performance Standards. (See 21 CFR 1020.30(k), (l), (m)(3), 
779  (n), 1020.31(b)(2), (c)(3), (d)(2)(iii), (e)(4), (g)(3), (h)(2), (l), (m)(3), 1020.32((a)(2), (b)(1), 
780  (d)(3)).  Is a manufacturer required to develop its quality control testing program to use these 
781  test methods exactly? 
782   
                                                 
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783    ANSWER:  It is the manufacturers responsibility to ensure that its testing program ensures that 
784  diagnostic x-ray equipment conforms to the applicable Performance Standards (21 CFR 
785  1010.2(c)) once assembled according to the Information to be provided to assemblers (21 CFR 
786  1020.30(g)). The testing methods referenced in the Performance Standards describe how FDA 
787  determines compliance with the Performance Standards when performing testing under 21 CFR 
788  1005.10.  It is the component manufacturers responsibility to use test methods that provide 
789  assurance that after assembly into a finished x-ray system, its products will comply with all 
790  applicable performance standards when tested using the test methods provided in the 
791  Performance Standards. It is also the component manufacturers responsibility to maintain 
792  records pertaining to its quality control testing (21 CFR 1002.30). 
793   
794  40. QUESTION:  Is it permissible to round off measured values obtained during testing if the 
795  measured values are slightly in excess of numerical limits stated in the Performance Standards 
796  and the rounding would allow the values to fall within the regulatory limits? 
797    
798  ANSWER:  No.  The regulatory limits in the Performance Standards are absolute values and as 
799  such, they cannot be exceeded.  Rounding measured test results to obtain compliant values is 
800  not acceptable.  For example, during testing of a fluoroscopic system, a measured maximum air 
801  kerma rate (after taking into account test measurement uncertainties) of 88.1 mGy per minute 
802  was obtained.  Since the limit for the applicable requirement is 88 mGy per minute for this 
803  system, the measured value of 88.1 mGy per minute exceeds the limit in the standard, and the 
804  unit is not compliant.  We recommend manufacturers (including assemblers) employ action 
805  limits more stringent than the regulatory limit to assure that equipment meets all numerical 
806  limits in the relevant Performance Standards. 
807   
808  41. QUESTION:  What is meant by the expression measurement criteria as related to 
809  technique factors in 21 CFR 1020.30(h)(3)(viii)? 
810    
811  ANSWER:  The regulations define technique factors such as peak tube potential, tube current, 
812  etc. (21 CFR 1020.30(b)).  However, the definitions are general in nature and more precise 
813  information is needed to interpret the technique factors.  Specifically, the criteria used to obtain 
814  the indicated technique factors must be given (21 CFR 1020.30(h)(3)(viii)).  For example, when 
815  measuring exposure time for three-phase equipment, one manufacturer may specify the 
816  measurement by defining it as the time between the beginning and end of the exposure cycle, 
817  while another manufacturer may define it in some other way.  In some cases, the measurement 
818  criteria may vary among models produced by the same manufacturer.  A statement of the 
819  measurement criteria used must be provided in the manufacturers literature to allow 
820  meaningful comparisons (21 CFR 1020.30(h)(3)(viii)). 
821   
822  42. QUESTION:  The linearity requirement of 21 CFR 1020.31(c) is interpreted to apply to the x-
823  ray system rather than individual components.  Some systems are composed of components that 
824  may have different maximum limiting specifications.  If so, is the linearity requirement of the 
825  system in a compliance test restricted to the maximum value as specified by the manufacturer's 
826  rating of the limiting component?   
827   
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828  ANSWER:  Yes.  The requirement in 21 CFR 1020.31(c) applies to the x-ray system, and 
829  testing compliance for linearity of the maximum milliampere-second product selection or 
830  maximum current setting of the system is limited by the manufacturer's rating of the limiting 
831  component. 
832   
833  43. QUESTION:  When measuring leakage from the diagnostic source assembly, may the main 
834  beam be blocked at the exit end of the beam-limiting device?  
835   
836  ANSWER:  Yes.  Note that, as defined in 21 CFR 1020.30(b), leakage radiation means 
837  radiation emanating from the diagnostic source assembly except for . . . [t]he useful beam; and 
838  useful beam is defined in 21 CFR 1020.30(b) as radiation which passes through the tube 
839  housing port and the aperture of the beam-limiting device . . . .  This means radiation passing 
840  through the aperture of the beam-limiting device is not leakage radiation and therefore is not 
841  subject to the leakage requirement.  Thus, the proposal of blocking the aperture at the exit end 
842  of the beam-limiting device is appropriate.  
843   
844  E. Models (See also question 33) 
845   
846  44. QUESTION:  A firm manufactures several slightly different versions of certain component 
847  models.  Must each version have its own unique model number? 
848   
849  ANSWER:  The answer depends on the differences among the versions.  21 CFR 1000.3(o) 
850  defines model as any identifiable, unique electronic product design, and refers to products 
851  having the same structural and electrical design characteristics and to which the manufacturer 
852  has assigned a specific designation to differentiate between it and other products produced by 
853  that manufacturer."  If the different versions have different structural or electrical design 
854  characteristics, including compatibility issues, they must have different model numbers (21 
855  CFR 1020.30(e)).  However, if the differences are cosmetic (such as different paint colors), it is 
856  acceptable to use the same model number for the different versions.  
857   
858  45. QUESTION:  Under 21 CFR 1020.30(e), each certifiable component must have a model and 
859  serial number.  May manufacturers use any alphanumeric format in standard English characters 
860  for these numbers, such as BLK012, 100245, or ALMM?  
861   
862  ANSWER:  Any alphanumeric format is acceptable for model and serial numbers, as long as the 
863  model number and the serial number are unique to that component, or approved single-labeled 
864  systems or single-labeled sub-system as authorized by FDA.  
865   
866  F. Product Reports 
867   
868  46. QUESTION: Should reports be submitted in English? 
869   
870  ANSWER: Yes, all required information and reports should be in the English language to allow 
871  for faster review by FDA. 
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872   
873  47. QUESTION:  Who is responsible for submitting annual reports?  
874   
875  ANSWER:  The manufacturer of an electronic product, including the manufacturer of a 
876  certifiable component, is responsible for filing all required reports as specified in Table 1 under 
877  21 CFR 1002.1.  The manufacturers designated U.S. agent or the importer who is an employee 
878  of, or contractor to, the manufacturer may submit the reports on behalf of a foreign 
879  manufacturer. 
880   
881  48. QUESTION:  Are manufacturers permitted to update product reports in their annual  
882  reports?  
883   
884  ANSWER:  It depends.  21 CFR 1002.13(c) states that new models of a model family do not 
885  require supplemental reports prior to introduction into commerce if they do not involve 
886  changes in radiation emission from the product or are not required for compliance with a 
887  performance standard.  These model numbers should be reported in quarterly updates to the 
888  annual report (21 CFR 1002.13(c)).  However, when a manufacturer updates a product 
889  report, FDA recommends that it do so through either: (1) the submission of a new product 
890  report as described in 21 CFR 1002.10, or (2) supplements to the affected product report as 
891  described in 21 CFR 1002.11. 
892   
893  49. QUESTION:  A manufacturer changed the kilovolts peak (kVp) accuracy specifications of one 
894  of the models of an x-ray control it manufactures from + 10% to + 5%.  It is understood that the 
895  manufacturer needs to report the change to FDA.  Should it file a new product report or a 
896  supplemental report? 
897   
898  ANSWER:  Since the firm has changed the performance specifications for the x-ray control, it 
899  must report this change prior to the introduction into commerce of the new model (21 CFR 
900  1002.11(b)).  FDA recommends that the firm submit a supplement under to the initial product 
901  under 21 CFR 1002.11 rather than a new product report.  The supplement should include the 
902  submission of test data to demonstrate compliance with the new specifications.   
903   
904  G. Assembly (See also questions 5, 6, 23, and 38)  
905   
906  For additional assembler information see FDAs guidance entitled Guidance for Industry and Food 
907  and Drug Administration Staff - Assemblers Guide to Diagnostic X-Ray Equipment.11 
908   
909  47. QUESTION:  It is understood that the Form FDA 2579, Report of Assembly of a Diagnostic 
910  X-ray System is used by assemblers to report the installation of diagnostic x-ray systems 
911  and/or their major components.  In a case where purchasers or their employees install certified 
912  components or systems, do the purchasers then become assemblers, as defined in the 
913  regulations?  Must they complete and file Form FDA 2579?  
                                                 
11https://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/UCM25778
3.pdf 
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914   
915  ANSWER:  Yes, in this situation, the purchasers or their employees become assemblers.  21 
916  CFR 1020.30(b) defines an assembler as any person engaged in the business of assembling, 
917  replacing, or installing one or more components into a diagnostic x-ray system or subsystem. 
918  The term includes the owner of an x-ray system or his or her employee or agent who assembles 
919  components into an x-ray system that is subsequently used to provide professional or 
920  commercial services.  Therefore, anyone who installs certified components or systems meets 
921  the definition of an assembler (21 CFR 1020.30(b)), and must file a Form FDA 2579 (21 CFR 
922  1020.30(d)(1) unless they meet one of the exceptions to the reporting requirements provided 
923  under 21 CFR 1020.30(d)(2).  For additional details and exceptions on when to file Form FDA 
924  2579, see FDAs guidance entitled Assemblers Guide to Diagnostic X-Ray Equipment.12  
925  Information on obtaining Form FDA 2579 may be found at 
926  http://www.fda.gov/AboutFDA/ReportsManualsForms/Forms/default.htm.  There is also an 
927  option for electronic submission of Form FDA 2579.  For more information, see FDAs 
928  website.13  
929   
930  49. QUESTION:  Must a Form FDA 2579 be filed when an assembler installs used certified 
931  equipment that have been donated?  
932   
933  ANSWER:  Yes.  The regulations make no distinction regarding the method of acquisition of 
934  the equipment.  When an assembler installs certified equipment for use on humans, they are 
935  required to file Form FDA 2579 (21 CFR 1020.30(d)(1)), regardless of how the equipment is 
936  acquired. 
937   
938  50. QUESTION:  What date should be used as the date of installation on the Form  
939  FDA 2579? 
940   
941  ANSWER:  The date of installation of an x-ray system or component is considered to be the 
942  date the x-ray system is released by the assembler to the facility or user for use on humans.  
943  Assemblers have fifteen (15) days from the date of installation to complete and distribute Form 
944  FDA 2579 before they are considered to be in violation of 21 CFR 1020.30(d)(1).  The Form 
945  FDA 2579 should properly indicate the actual date of installation, and not the date on which the 
946  assembler completes and distributes the Form FDA 2579.   
947   
948  51. QUESTION:  What are the manufacturers and assemblers responsibilities relative to final 
949  testing of a newly-assembled x-ray system or component before it is released to the user? 
950   
951  ANSWER:  Manufacturers Responsibilities:  Manufacturers certify that each of their products 
952  meet all applicable requirements when installed according to their instructions for assembly, 
953  installation, adjustment, and testing.  Descriptions of any testing that must be performed after 
954  installation in order to ensure compliance with the applicable Performance Standards should be 
                                                 
12https://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/UCM25778
3.pdf 
13 http://www.fda.gov/ForIndustry/FDAeSubmitter/ucm107879.htm 
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955  included in these instructions.  This information shall be provided to assemblers (21 CFR 
956  1020.30(g). 
957   
958  Step-by-step instructions and a thorough explanation of the required test equipment should be 
959  provided.  The instructions should include a requirement to record those key data that will 
960  permit demonstration at a later date that all specified tests were performed and that the 
961  equipment was installed and tested in compliance with the assembly instructions.  
962  Manufacturers who rely on the results from tests performed during assembly to support their 
963  certification but do not include final compliance testing in their assembler instructions may have 
964  their quality control and testing programs disapproved (21 CFR 1010.2(c)).  
965   
966  Assemblers Responsibilities:  Assemblers of diagnostic x-ray equipment must perform all 
967  testing specified in the assembly instructions provided by the component or system 
968  manufacturer(s) at the time of installation (21 CFR 1020.30(d)).  Assemblers who fail to 
969  perform, and document the results of, final compliance tests as required by the manufacturer(s) 
970  may be considered by the FDA to have issued a false and misleading certification and may be 
971  subject to regulatory action by the FDA.  Assemblers shall not be liable for noncompliance of a 
972  certified component if the assembly of that component was performed according to the 
973  component manufacturers instruction (21 CFR 1020.30(d)). 
974   
975  52. QUESTION:  An assembler determines that the available rated line voltage and/or range of line 
976  voltage regulation is not within the manufacturer's specified requirements.  May this installation 
977  be completed? 
978   
979  ANSWER:  No.  The installation, as described, is not permitted.  The manufacturer must 
980  provide assembly instructions adequate to assure compliance of its components with the 
981  applicable Performance Standards (21 CFR 1020.30(c)) which must include a statement of the 
982  rated line voltage and the range of line-voltage regulation (21 CFR 1020.30(g)(1)), and the 
983  assembler shall assemble, install, adjust and test the certified components according to the 
984  instructions of the manufacturer (21 CFR 1020.30(d)).  This assembly cannot be performed 
985  according to the manufacturers instructions and should not be completed. 
986   
987  53. QUESTION:  A firm manufactured and sold a fluoroscopic C-arm system that was fully 
988  compliant with the Performance Standards if installed and assembled according to its 
989  instructions.  However, this particular system was incorrectly installed and assembled, and is 
990  noncompliant with the Performance Standards.  Is the manufacturer responsible for correcting 
991  the noncompliant system? 
992   
993  ANSWER:  No.  Manufacturers are not responsible for noncompliance of their products if that 
994  noncompliance is due solely to the improper installation or assembly of that product by another 
995  person (21 CFR 1020.30(c)).  However, manufacturers are responsible for providing assembly 
996  instructions adequate to assure compliance of their components with the applicable provisions 
997  of the Performance Standards (21 CFR 1020.30(g)).   
998   
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999  54. QUESTION:  A firm manufactured, sold, and installed a fluoroscopic C-arm system that was 
1000  fully compliant with the Performance Standards when it was assembled.  However, the owners 
1001  service engineer adjusted the tube output to increase the air kerma rate.  The maximum air 
1002  kerma rate after the adjustment was found to be 120 mGy per minute and as a result, the system 
1003  fails to comply with 21 CFR 1020.32(d)(2)(ii).  The facilitys medical physicist notified the 
1004  assembler that the system needs to be adjusted to comply with the Performance Standards.  Is 
1005  the assembler or manufacturer responsible for adjusting the system at no cost to the user? 
1006   
1007  ANSWER:  No.  If the users service engineer did not adjust the system by following the 
1008  assembly, installation, adjustment, and testing (AIAT) instructions, the manufacturer is not 
1009  responsible for the failure to comply (see question 53).  However, if the user adjusted the 
1010  system by following the assembly, installation, adjustment, and testing (AIAT) instructions, and 
1011  the resulting air kerma rate did not meet the requirement provided in 21 CFR 1020.32(d)(2)(ii), 
1012  the manufacturer is responsible for the failure to comply and must act according to 21 CFR 
1013  1003.10 including notification to the Secretary (21 CFR 1003.20), notification to affected 
1014  persons (21 CFR 1003.21), and unless exempted from notification requirements (21 CFR 
1015  Subpart D), repurchase, repair, or replace the system at no cost to the user (21 CFR 1004).  
1016   
1017  55. QUESTION:  Section 21 CFR 1020.31(b)(2), Measuring Compliance appears to limit an 
1018  assembler to install systems where only plus or minus 1 percent (1%) line-voltage regulation is 
1019  available.  Is this correct?  
1020   
1021  ANSWER:  No.  The plus or minus 1 percent (1%) line-voltage regulation in 21 CFR 
1022  1020.31(b)(2) is an FDA test condition only.  This means if the line voltage regulation 
1023  (expressed as a percent) for one measurement departs from the mean value of line voltage 
1024  regulation for all 10 measurements (expressed as a percent) by more than 1 percent, the test 
1025  result is not valid for determining compliance.  See question 39. 
1026   
1027  (1) Assembly Instructions (See also questions 51, 53, and 54) 
1028  Manufacturers of components listed in 21 CFR 1020.30(a)(1) are required to provide assemblers 
1029  with adequate instructions for assembly, installation, adjustment and testing of those components 
1030  (21 CFR 1020.30(g)).  The instructions must be adequate to assure that the products will comply 
1031  with the applicable provisions of the Performance Standards when assembled, installed, adjusted 
1032  and tested as directed (21 CFR 1020.30(g)).  Manufacturers of diagnostic x-ray systems and 
1033  components must provide these instructions to assemblers and, upon request, to other interested 
1034  parties at a cost not to exceed the cost of publication and distribution (21 CFR 1020.30(g)).  
1035  However, manufacturers are not required to disclose trade secrets or confidential information.    
1036  In addition, manufacturers of x-ray equipment, including components, are required to provide to 
1037  purchasers, and upon request, to others manuals or instruction sheets with the information required 
1038  under 21 CFR 1020.30(h). 
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1039  Additional information is available in FDAs guidance entitled Information Disclosure by 
1040  Manufacturers to Assemblers for Diagnostic X-ray Systems.14   
1041  56. QUESTION:  Section 21 CFR 1020.30(g) requires manufacturers to provide adequate 
1042  instructions to complete a compliant installation of their component(s) into a diagnostic x-ray 
1043  system.  However, assembly of a manufacturers system may require the use of unique software 
1044  programs to assure a compliant assembly.  Must the manufacturer provide access to these 
1045  software programs as part of the information to be provided to assemblers? 
1046    ANSWER:  Yes.  If assembly, installation, adjustment, and testing of the certified components 
1047  requires the use of unique software programs then access to those software programs should be 
1048  provided to assemblers and, upon request, to others at a cost not to exceed the cost of 
1049  publication and distribution (21 CFR 1020.30(g)).  If adequate instructions to complete a 
1050  compliant installation can only be conveyed by other modes (e.g., instructional videos or in-
1051  person training) then those forms of instructions should similarly be provided at a cost not to 
1052  exceed the cost of publication and distribution. 
1053  Some manufacturers bundle the unique software programs covered by 1020.30(g) with other 
1054  types of proprietary software; in some instances, the proprietary software cannot be deleted 
1055  from the bundled information.  Nothing in section 1020.30 prohibits bundling software 
1056  information or programs; however, the practice does not relieve manufacturers of their 
1057  responsibilities under the performance standard to provide the necessary documentation or 
1058  software at a cost not to exceed the cost of publication and distribution. 
1059  57. QUESTION:  Section 21 CFR 1020.30(g) requires manufacturers to provide adequate 
1060  instructions to complete a compliant installation of their component(s) into diagnostic x-ray 
1061  systems.  It is understood that if software is required to assure a compliant assembly, the 
1062  manufacturer is required to provide the software.  However, does 21 CFR 1020.30(g) apply to 
1063  ancillary software developed by the manufacturer that may be helpful but is not required for 
1064  such an installation?  
1065  ANSWER:  No.  Some manufacturers have developed proprietary software beyond that 
1066  required by 21 CFR 1020.30(g) for use as an aid during the assembly process.  They are not 
1067  required to provide such additional ancillary software.   
1068  Additional information is available in FDAs guidance entitled Information Disclosure by 
1069  Manufacturers to Assemblers for Diagnostic X-ray Systems.15 
1070  58. QUESTION:  Are manufacturers required by the Performance Standards to provide 
1071  maintenance and repair instructions to users or others? 
                                                 
14http://www.fda.gov/downloads/Radiation-
EmittingProducts/ElectronicProductRadiationControlProgram/IndustryGuidance/UCM136731.pdf 
15http://www.fda.gov/downloads/Radiation-
EmittingProducts/ElectronicProductRadiationControlProgram/IndustryGuidance/UCM136731.pdf 
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1072  ANSWER:  No.  The Performance Standards only require manufacturers to provide a 
1073  schedule of maintenance (if any) necessary to maintain compliance with Performance 
1074  Standards (21 CFR 1020.30(h)(1)(ii)).  For more direction regarding information disclosure 
1075  by manufacturers to assemblers, see FDAs guidance entitled Information Disclosure by 
1076  Manufacturers to Assemblers for Diagnostic X-Ray Systems.16 
1077  59. QUESTION:  How does the FDA interpret the phrase cost not to exceed the cost of publication 
1078  and distribution as used in 21 CFR 1020.30(g)?  
1079  ANSWER:  Manufacturers may charge for the cost of producing each additional package or unit 
1080  of instructions.  The charge can incorporate factors such as the cost of paper, labor, use of a 
1081  copying machine, shipping cost, or other costs associated with each package the manufacturer 
1082  provides under the Performance Standard.  For software, recoverable charges equivalent to 
1083  printed materials would include such factors as the cost of the labor (e.g., technical and clerical) 
1084  of producing such additional package or unit, computer disks, and packaging materials used to 
1085  produce each additional unit of software.  
1086  60. QUESTION:  Some manufacturers always include the assembly of their x-ray equipment as part 
1087  of the initial purchase.  Are such manufacturers required to provide assembly instructions to 
1088  anyone who requests copies? 
1089   
1090  ANSWER:  Yes.  Assembly instructions must be provided to assemblers and, upon request to 
1091  others at a cost not to exceed the cost of publication and distribution (21 CFR 1020.30(g)).  
1092  Even though the manufacturer may perform the initial assembly, the system could subsequently 
1093  be moved or sold and might need to be dismantled and then re-assembled by an assembler.   
1094   
1095  H. Accidental Radiation Occurrence 
1096   
1097  61. QUESTION:  Does the requirement in 21 CFR 1002.20 concerning the reporting of 
1098  accidental radiation occurrences apply to foreign manufacturers of products sold in the 
1099  U.S.? 
1100   
1101  ANSWER:  Yes.  Foreign manufacturers of products sold in the U.S. are subject to the reporting 
1102  requirements provided in 21 CFR 1002.20, and all of the requirements applicable to foreign 
1103  manufacturers of products sold in the U.S. 
1104     
1105  I.  Records 
1106   
1107  62. QUESTION:  Sections 21 CFR 1002.30(a)(1) and (a)(2) call for maintaining records pertaining 
1108  to (1) quality control procedures, and (2) test results.  How do these requirements apply to 
1109  foreign manufacturers and where does FDA expect the records to be maintained?  
1110   
                                                 
16 http://www.fda.gov/downloads/Radiation-
EmittingProducts/ElectronicProductRadiationControlProgram/IndustryGuidance/UCM136731.pdf 
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1111  ANSWER:  Because all manufacturers are required to have quality control and testing programs 
1112  (21 CFR 1010.2(c)), they are responsible for generating and maintaining records of the results 
1113  of these programs.  As long as the records are available within a reasonable timeframe during 
1114  FDA inspections of the manufacturing facility, it does not matter where the records are stored. 
1115   
1116  J. Defects (See also questions 53 and 54) 
1117   
1118  63. QUESTION:  Does FDA consider a failure which prevents a diagnostic x-ray system from 
1119  producing x-rays to meet the definition of a defect as described in 21 CFR 1003.2(b)(3)? 
1120   
1121    ANSWER:  If the failure to produce x-rays is the result of the design, production, or assembly 
1122  of the x-ray system and the system appears ready to emit x-rays on command but fails to emit x-
1123  rays, then the failure will be considered a defect by FDA under 21 CFR 1003.2(b)(3) because 
1124  the product fails to accomplish the intended purpose. 
1125   
1126  64. QUESTION:  Does FDA consider a non-radiation related failure (e.g., broken wheel or drive 
1127  mechanism failure on a mobile x-ray system), which causes the device to fail to accomplish the 
1128  intended purpose, to meet the definition of a defect as used in 21 CFR 1003.2(b)(3)? 
1129   
1130    Answer:  No.  For diagnostic x-ray systems, FDA considers only those occurrences that are the 
1131  results of the design, production, or assembly of the x-ray system and related to the emission of 
1132  radiation including the failure to emit radiation when expected, to be defects under the failure to 
1133  accomplish the intended purpose designation in 1003.2(b)(3).  In this case, the broken wheel or 
1134  drive mechanism failure may be the result of the design, production, or assembly of the system 
1135  but it is not related to the emission of radiation and, therefore, does not meet the definition of a 
1136  defect. 
1137   
1138  65. QUESTION:  Does a burned-out x ray tube that does not produce x rays fall under the 
1139  definition of a defect as used in 21 CFR 1003.2(b)(3)?   
1140   
1141  ANSWER:  Under 21 CFR 1003.2(b)(3), a defect is defined as a product which as a result of 
1142  its design, production or assembly... fails to accomplish the intended purpose.  Because x-ray 
1143  tubes have an expected lifetime that is influenced by the age and use of the tube, the failure of 
1144  an x-ray tube due to such causes will generally not be considered a defect under 21 CFR 
1145  1003.2(b)(3) by FDA but rather a normal and expected failure of the x-ray tube.  However, an 
1146  x-ray tube which burned out prematurely as a result of the design, production or assembly of the 
1147  tube housing assembly or other components in the system may be considered a defect under 21 
1148  CFR 1003.2(b)(3).  See also question 64. 
1149   
1150  66. QUESTION:  Is a tube with an excessively large focal spot considered a defect under 21 CFR 
1151  1003.2 (i.e., the tube fails to meet the manufacturers specifications for focal spot size)? 
1152   
1153  ANSWER:  If a tube is sold with a focal-spot size that exceeds its specifications, then there is a 
1154  defect - the product does not meet its own specifications relating to the emission of electronic 
1155  product radiation (21 CFR 1003.2(b)(1)).  If the tube met specifications when it was sold, but no 
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1156  longer meets the specifications due to age or misuse, that failure to meet specifications may or 
1157  may not be considered a defect.    
1158   
1159  The manufacturer bears the burden of proof in establishing that a defect or noncompliance is 
1160  due to a cause other than faulty manufacture.  This may include information to distinguish 
1161  between normal wear and damage resulting from misuse of the equipment.  For example, a 
1162  certain amount of normal wear will occur in electronic products.  If such normal wear results in 
1163  radiation emitted by the product exceeding the limit prescribed in an applicable standard, the 
1164  manufacturer may be charged with noncompliance because of his failure to design the product 
1165  to maintain an acceptable level of radiation leakage over its useful life.  See FDAs Compliance 
1166  Policy Guide (CPG) 390.200.17 
1167   
1168  67. QUESTION:  A manufacturer has found that some diagnostic x-ray systems that it shipped are 
1169  noncompliant with the beam quality requirements under 21 CFR 1020.30(m)(1) because the 
1170  manufacturer failed to install an aluminum filter plate in these systems.  The manufacturer 
1171  knows that other systems tested at its manufacturing facility passed this requirement with the 
1172  filter plate installed, and therefore installing filter plates will correct the noncompliant systems.  
1173  Would it be acceptable for the manufacturer to start correcting the noncompliant installed 
1174  systems concurrent with notification to FDA? 
1175   
1176  ANSWER:  Yes.  Upon discovery of a defect or failure to comply with an applicable 
1177  performance standard, a manufacturer shall immediately notify the FDA in accordance with 21 
1178  CFR 1003.20 (see 21 CFR 1003.10(a)).  Implementation of a corrective action plan may begin 
1179  prior to the plans approval by FDA.  However, if the plan fails to correct the noncompliance or 
1180  defect, or if FDA does not approve the corrective action plan, the manufacturer may be required 
1181  to perform additional actions (21 CFR 1004.2 and 1004.6).  To avoid these problems, a 
1182  manufacturer should contact FDA regarding its corrective action plan prior to the plans 
1183  implementation. 
1184   
1185  68. QUESTION:  What procedure does FDA follow upon discovering that a diagnostic x-ray 
1186  system or component fails to comply with the regulations or has a defect? 
1187   
1188  ANSWER:  FDA notifies the manufacturer of the defect or failure to comply by providing the 
1189  following in writing: 
1190   
1191  a.  How FDA determined that the product was noncompliant/defective (21 CFR 
1192  1003.11(a)(2)); 
1193  b.  Details about the noncompliance including a reference to the specific regulation(s) with 
1194  which the product is noncompliant (21 CFR 1003.11(a)(1)); 
1195  c.  In the case of a defect, details about why the product is defective; 
1196  d.  A reasonable period of time during which the manufacturer may present its views and 
1197  evidence to establish that there is no failure of compliance or that the alleged defect does 
                                                 
17 https://www.fda.gov/ICECI/ComplianceManuals/CompliancePolicyGuidanceManual/UCM073911 
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1198  not exist or does not relate to the safety of the use of the product by reason of the 
1199  emission of electronic product radiation (21 CFR 1003.11(a)(3)); and 
1200  e.  The manufacturers obligation to repair, replace, or refund the cost of electronic 
1201  products. 
1202   
1203  K.  Fluoroscopy (See also question 54) 
1204   
1205  69. QUESTION:  On June 10, 2006, several new requirements became effective for fluoroscopic x-
1206  ray systems manufactured on or after that date.  If new components manufactured on or after 
1207  that date are added to a fluoroscopic system manufactured before June 10, 2006, are the new 
1208  requirements applicable to the system? 
1209   
1210  ANSWER:  No, the new requirements that became effective for fluoroscopic x-ray systems 
1211  manufactured on or after June 10, 2006, are only applicable if: 
1212   
1213  1.  The complete system is certified and the systems date of manufacture falls on or after June 
1214  10, 2006; or 
1215   
1216  2.  All of the certified components in the system were manufactured on or after June 10, 2006, 
1217  as provided by each of their identification labels. 
1218   
1219  70. QUESTION:  The regulatory changes that became effective June 10, 2006 require fluoroscopic 
1220  systems manufactured on or after that date to have a last image hold display and equipment to 
1221  clearly indicate whether a live image or the last image hold is displayed (21 CFR 
1222  1020.32(j)(3)).  How does FDA interpret the requirement to clearly indicate which image is 
1223  being displayed? 
1224   
1225  ANSWER:  Any readily recognizable and distinguishable wording, icon, or image that is 
1226  prominently displayed on the images or at the location where the image hold and live image 
1227  information is displayed, in conjunction with clear explanations and descriptions in the 
1228  information to be provided to users (21 CFR 1020.30(h)(1)(i)) (e.g., manuals or instructions) 
1229  will satisfy the requirement under 21 CFR 1020.32(j)(3).   
1230   
1231  71. QUESTION:  21 CFR 1020.32(k) specifies that fluoroscopic systems manufactured on or after 
1232  June 10, 2006 must display at the fluoroscopists working position both the air kerma rate 
1233  (AKR) and the cumulative air kerma.  Would the display of the dose area product (DAP) (also 
1234  called kerma-area product) and the cumulative DAP satisfy these requirements? 
1235   
1236  ANSWER:  No.  Display of the DAP and cumulative DAP provide significantly different 
1237  information relating to the x-ray field and do not satisfy 21 CFR 1020.32(k). 
1238   
1239  72. QUESTION:  If a fluoroscopic system uses an under-table tube, and is also capable of spot-film 
1240  exposures, is the tube considered a radiographic tube when used for spot-film exposures?  If it is 
1241  considered a radiographic tube, where should the indicator be placed to show that it was 
1242  selected for an exposure as required by 21 CFR 1020.31(k)?  
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1243   
1244  ANSWER:  The under-table tube is considered a radiographic tube when used for spot-film 
1245  exposures, but a separate indicator is not required.  21 CFR 1020.31(k) applies to the situation 
1246  where two or more tubes are controlled by the same exposure switch.  Even though the tube is 
1247  typically controlled by a separate exposure switch when used for radiography, it is not a 
1248  separate tube.  Therefore, the separate indication required by 21 CFR 1020.31(k) does not apply 
1249  to the scenario proposed in the question.  
1250   
1251  73. QUESTION:  A fluoroscopic x-ray system was manufactured after May 19, 1995 and the 
1252  system limits the air kerma rate (AKR) to 88 mGy per minute (10 R per minute) by limiting the 
1253  maximum peak tube potential.  However, the fluoroscopic AKR could exceed the 88 mGy per 
1254  minute limit momentarily (less than two seconds) if the operator changes to a higher mA setting 
1255  while x-rays are being produced.  This occurs during the time that the peak tube potential is 
1256  driven down to a value sufficient to limit the AKR to 88 mGy per minute.  The alternative 
1257  would be to terminate production of x-rays during this time, but that could lead to a loss of 
1258  important diagnostic information.  The audible signal for high-level control (HLC) mode is set 
1259  so that anytime the AKR exceeds 88 mGy per minute, the signal is activated.  Is such a system 
1260  acceptable?  
1261   
1262  ANSWER: No.  For fluoroscopic equipment manufactured on or after May 19, 1995, AKR 
1263  greater than 88 mGy per minute are allowed only during activation of HLC or during recording 
1264  of fluoroscopic images (21 CFR 1020.32(d)(2)(iii)).  A special means of HLC activation is 
1265  required (21 CFR 1020.32(d)(2)(iii)(C)).  When HLC is activated the audible signal must also 
1266  be activated, regardless of the actual air kerma rate (21 CFR 1020.32(d)(2)(iii)). 
1267     
1268  74. QUESTION: A manufacturer is planning to provide a high-level control (HLC) mode switch for 
1269  fluoroscopy that does not require continuous pressure for activation.  The manufacturer feels 
1270  this would be safer because it would avoid accidental use of HLC by operators, free the operator 
1271  from using a hand or foot consciously and allow them to concentrate on the clinical procedure, 
1272  and would still provide a visual and audible warning immediately if the previous operator had 
1273  left the unit in HLC mode.  Is this acceptable? 
1274   
1275  ANSWER:  No.  HLC mode shall be operable only when continuous manual activation of the 
1276  fluoroscopic HLC switch is provided by the operator (21 CFR 1020.32(d)(2)(iii)(C)).  A switch 
1277  that activates the HLC mode without continuous pressure could activate HLC mode 
1278  indefinitely, and does not provide the positive means required in the Performance Standards (21 
1279  CFR 1020.32(d)(2)(iii)(C)).  
1280   
1281  75. QUESTION:  In certain fluoroscopy systems, the peak tube current is not user selectable.  It 
1282  remains constant and the average current changes automatically by varying pulse width and 
1283  frequency (frame rate).  In these systems, where peak tube current is held constant, will a label 
1284  that provides the specified tube current meet the requirement of 21 CFR 1020.32(f)?   
1285   
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1286  ANSWER: No.  21 CFR 1020.32(f) requires continuous indication of both x-ray tube potential 
1287  and tube current during any fluoroscopic exposure.  A label is not an acceptable substitute for a 
1288  continuous indication and is noncompliant with 21 CFR 1020.32(f). 
1289   
1290  76. QUESTION:  The June 10, 2006 regulatory changes in the fluoroscopic regulations included a 
1291  change under 21 CFR 1020.32(h)(2).  A preset timer having a maximum cumulative time of 5 
1292  minutes is no longer required.  Since this timer is not required for new equipment, may a 
1293  manufacturer remove or disable the 5 minute preset feature from older equipment when 
1294  customers request this modification? 
1295   
1296  ANSWER:  Yes, as long as the fluoroscopic system is modified appropriately.  The regulatory 
1297  changes that became effective on June 10, 2006 removed the requirement for the 5 minute 
1298  preset timer limit, but replaced it with new requirements for several additional features as 
1299  specified in 21 CFR 1020.32(h)(2).  Under 21 CFR 1020.30(q)(2), the owner of a diagnostic x-
1300  ray system may modify the system as long as the modification does not create a failure to 
1301  comply with any requirements in effect at the time the affected system or component was 
1302  manufactured.  Simply removing or disabling the timer would create such a problem.  However, 
1303  under 21 CFR 1020.32(h)(1)(i) this modification is permitted if the system is also modified to 
1304  meet the requirements of 21 CFR 1020.32(h)(2), and if a label stating Modified to comply with 
1305  21 CFR 1020.32(h)(2) is affixed to the control. 
1306   
1307  L. Specific components 
1308   
1309  (1)  Beam Limiting Devices (see also questions 12, 15, 19, 78, and 98) 
1310   
1311  77. QUESTION:  To produce a radiograph in a particular panoramic dental system, the diagnostic 
1312  source assembly and film cassette rotate about the patients head at a fixed source-image 
1313  receptor distance (SID) while the film is advanced through the film holder.  A narrow slit in the 
1314  film cassette holder allows the useful x-ray beam to pass through while blocking scatter 
1315  radiation from the exposed and unexposed sections of the film.  This produces a laminographic 
1316  view of the patients jaw and teeth.  Is such a design consistent with the requirements of 21 CFR 
1317  1020.31?  
1318   
1319  ANSWER:  Yes.  However, for the panoramic unit described above, the image receptor size is 
1320  equal to that portion of the film instantaneously exposed through the slot in the cassette holder, 
1321  rather than the entire image receptor.  This means that for dental panoramic type units designed 
1322  with a fixed SID and one image receptor size, the dimensions of the portion of the x-ray beam 
1323  whose intensity is equal to or greater than 25 percent of the maximum intensity of the x-ray 
1324  field (21 CFR 1020.30(b)) at the front plane of the cassette holder must be limited to the 
1325  dimensions of the film instantaneously exposed through the slot in the cassette holder (21 CFR 
1326  1020.31(f)(2)) and the center of the x-ray field must be aligned with the center of the slot in the 
1327  cassette holder within 2 percent of the SID.  Alternatively, means may be provided to both size 
1328  and align and x-ray field such that the x-ray field at the front plane of the cassette holder does 
1329  not extend beyond any edge of the slot in the cassette holder. 
1330   
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1331  For dental panoramic type units in which the SID is variable, the x-ray beam dimensions where 
1332  the intensity is equal to or greater than 25 percent of the maximum intensity of the x-ray field 
1333  (21 CFR 1020.30(b)) at the front plane of the cassette holder shall not exceed the dimensions of 
1334  the slot by more than 2 percent of the SID (21 CFR 1020.31(f)(4)).  Alternatively, means may 
1335  be provided to both size and align and x-ray field such that the x-ray field at the front plane of 
1336  the cassette holder does not extend beyond any edge of the slot in the cassette holder. 
1337   
1338  78. QUESTION:  A firm plans to manufacture and assemble cephalometric attachments designed 
1339  for use with conventional intraoral dental x-ray equipment.  What beam limitation requirements 
1340  are applicable to the resulting system? 
1341   
1342  ANSWER:  When a certified cephalometric BLD is added to any existing diagnostic x-ray 
1343  system, means must be provided to limit and align the x-ray field to the image receptor as 
1344  specified in 21 CFR 1020.31(f)(2) or (f)(4), depending on whichever regulation is applicable.  
1345  Therefore, if the means for alignment is dependent on other apparatuses or certified components 
1346  being installed (e.g., head positioners, cassette holders), it may be necessary to install a 
1347  complete cephalometric system.  If the resulting cephalometric system is designed to be 
1348  operated at one SID and one image receptor size, 21 CFR 1020.31(f)(2) is applicable; 
1349  otherwise, 21 CFR 1020.31(f)(4) is applicable.  
1350   
1351  (2)  Controls (See also questions 20, 35, and 36) 
1352   
1353  79. QUESTION:  Users have requested that manufacturers install a remote exposure switch to 
1354  permit the operator to be located further away from the x-ray beam and patient than normally 
1355  would be permitted by the use of a retractable cord.  The remote exposure switch would be 
1356  provided in a separate box, on which are mounted the exposure switch, a light indicating that 
1357  power is on to the entire control, and a light that indicates exposure.  Is such an installation 
1358  allowed by the regulations? 
1359   
1360  ANSWER: Yes, as long as the following requirements are met:  
1361   
1362    The warning label (21 CFR 1020.30(j)) and technique factors to be used before an 
1363  exposure begins must be visible and legible from any position where the remote 
1364  exposure switch is mounted (21 CFR 1020.31(a)(1)); 
1365   
1366    At the remote location, the beam-on indicators required by 21 CFR 1020.31(j) are 
1367  provided (both a visual indication of x-ray production and a signal audible to the 
1368  operator to indicate that the exposure has terminated); and 
1369   
1370    The instructions for assembly governing this remote switch option clearly address the 
1371  two conditions above (21 CFR 1020.30(g)). 
1372   
1373  80. QUESTION:  When a diagnostic x-ray system with a single x-ray control is used to control the 
1374  operation of two or more diagnostic source assemblies (DSAs), how should the system indicate 
1375  which tube or tubes have been selected? 
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1376   
1377  ANSWER:  Where two or more radiographic tubes are controlled by one exposure switch, the 
1378  tube or tubes which have been selected must be clearly indicated before initiation of the 
1379  exposure (21 CFR 1020.31(k)).  This indication must be provided on both the x-ray control and 
1380  at or near the tube housing assembly that has been selected (21 CFR 1020.31(k)).  This could be 
1381  accomplished with a graphical representation of the x-ray system at the x-ray control which 
1382  indicates the active tube with lights or color accents.  Alternatively, clear language may be 
1383  presented to the user at the x-ray control such as under-table tube active or over-table tube 
1384  active. 
1385   
1386  81. QUESTION:  When a diagnostic x-ray system with a single x-ray control is used to control the 
1387  operation of two or more DSAs, does the linearity requirement (21 CFR 1020.31(c)) apply 
1388  between the two DSAs?  
1389   
1390  ANSWER:  No.  If two or more DSAs are operated from the same control, each combination of 
1391  DSA and control will be considered as a separate system for the purpose of determining 
1392  applicability of the linearity requirement.  Therefore, linearity is applicable for each such 
1393  system combination, but not between the two systems.  
1394   
1395  (3)  Filters 
1396  82. QUESTION:  How have the minimum half-value layer (HVL) requirements (21 CFR 
1397  1020.30(m)) changed since June 9, 2006? 
1398  ANSWER:  The minimum HVL requirements for all x-ray systems manufactured on or after 
1399  June 10, 2006, (except dental systems designed for use with intraoral image receptors) have 
1400  been increased as specified by Table 1 of 21 CFR 1020.30(m). 
1401  The shaded-gray column in Table 2 below (Table 1 of 21 CFR 1020.30(m)) shows the increased 
1402  values. 
1403  Table 2. Minimum HVL requirements (21 CFR 1020.30(m) TABLE 1) 
X-Ray Tube Voltage  Minimum HVL 
(kilovolt peak)  (mm of aluminum) 
Designed  Measured  Specified  IOther  IIOther 
Operating   Operating  Dental       X-Ray   X-Ray  
Range  Potential  Systems18  Systems19  Systems20 
Below 51  30  1.5  0.3  0.3 
                                                 
18 Dental x-ray systems designed for use with intraoral image receptors and manufactured after December 1, 1980. 
19 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. 
20 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. 
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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 
1404   
1405  85. QUESTION:  21 CFR 1020.30(m)(1) specifies that, for diagnostic x-ray systems, positive 
1406  means must be provided to ensure the minimum filtration beam quality requirement is met for 
1407  each exposure.  In systems having variable filtration capability, where special radiographic 
1408  techniques require temporary disengagement of the filter and/or mirror optic system, would a 
1409  special tool with appropriate warnings and instructions that would disengage the filtration 
1410  elements meet the requirements of positive means?  
1411   
1412  ANSWER:  No.  FDA does not believe a special tool would qualify as being a positive 
1413  means.  By positive means FDA suggests that the manufacturer design the equipment so that 
1414  exposure is inhibited until the proper filtration is in the beam (21 CFR 1020.30(m)(1)).  
1415  Although special tools may be used to remove the filter during servicing, the operator should 
1416  not have to routinely add and/or remove it during normal use.  In the case of a diagnostic x-ray 
1417  system that is to be operated with more than one thickness of filtration, this requirement can be 
1418  met by a filter interlocked with the kilovoltage selector that will prevent x-ray emissions if the 
1419  minimum required filtration is not in the beam. 
1420   
1421  NOTE:  A requirement to provide optional additional filtration is provided in 21 CFR 
1422  1020.30(m)(2) for certain fluoroscopic systems manufactured on or after June 10, 2006. 
1423   
1424  86. QUESTION:  Do the Performance Standards cover use of a filter of varying thickness (beam-
1425  shaper) to obtain a uniform exposure at the surface of the film during an examination?  
1426   
1427  ANSWER:  No.  The Performance Standards do not place requirements on such filtration, but 
1428  they do set requirements in Table 1 of 21 CFR 1020.30(m)(1) (see question 84) for minimum 
1429  beam quality.  FDA will test systems for compliance with the compensation filter in place and 
1430  the beam-limiting device opened to the widest setting to make the half-value layer 
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1431  determination.  Since the filtration is not uniform across the useful beam, the region of 
1432  minimum thickness will be the value used to determine compliance. 
1433   
1434  87. QUESTION:  A manufacturer produces an x-ray system rated nominally at 70 kVp and has 
1435  established a kVp tolerance of plus or minus 5 percent (5%).  If the measured kVp of the 
1436  system is 73, and referencing Table 1 of 21 CFR 1020.30(m)(1), must the minimum half-value 
1437  layer (HVL) be at least 2.6 mm of aluminum (by linear interpolation from the above 70 kVp 
1438  section) or 1.9 mm of aluminum (by linear extrapolation from the 51 to 70 kVp designed 
1439  operating range)? 
1440    
1441  ANSWER:  1.9 mm of aluminum is an acceptable value.  In 21 CFR 1020.30(h)(3) and 
1442  1020.31(a)(4) each manufacturer is required to establish and state its own technique factor 
1443  accuracy specifications.  If a machine is designed to operate only in the range of 51 to 70 kVp, 
1444  the appropriate range in Table 1 for determining HVL compliance is the 51 to 70 kVp range, 
1445  regardless of whether the measured kVp exceeds 70 or falls below 51 kVp.  If the measured 
1446  kVp value falls outside of this range, the manufacturer should determine the correct HVL by 
1447  linear extrapolation from Table 1 under 21 CFR 1020.30(m)(1).  The manufacturer should 
1448  extrapolate from the values for HVL given for the two kVp values (within the designed 
1449  operating range) that are closest to the measured kVp.  In this example, the HVL value for 73 
1450  kVp should be extrapolated from the 51 to 70 kVp operating range and the correct minimum 
1451  HVL is 1.89 mm of aluminum. 
1452   
1453  If a system is designed to operate in multiple kVp ranges, the appropriate range for determining 
1454  HVL compliance is dictated by the selected operating tube potential. 
1455     
1456  (4)  Image Receptors 
1457   
1458  88. QUESTION:  Under 21 CFR 1020.30(a)(1)(i)(F), the June 10, 2006 update of the Performance 
1459  Standards now includes Image receptors that are electrically powered or connected with the x-
1460  ray system manufactured on or after June 10, 2006, as certifiable diagnostic x-ray components.  
1461  How does FDA interpret this change and what requirements are applicable to the covered 
1462  products? 
1463   
1464  ANSWER:  FDA currently limits the applicability of 21 CFR 1020.30(a)(1)(i)(F) to only those 
1465  electrically-powered image receptors that are used as fluoroscopic image receptors.  This 
1466  includes image receptors that are used for a combination of both fluoroscopy and radiography.  
1467  FDA does not intend to enforce the requirements under 21 CFR 1020.30(a)(1)(i)(F) to image 
1468  receptors that are electrically powered or connected to radiographic only systems at this time. 
1469   
1470  NOTE: Additional requirements may apply to image receptors if they perform additional 
1471  functions where requirements are specified in the Performance Standards.  See question 7 where 
1472  adding x-ray control functionality to a digital detector is discussed as an example. 
1473  89. QUESTION:  What additional information is required to be provided to users regarding image 
1474  receptors that are electrically powered or connected? 
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1475  ANSWER:  For x-ray systems, manufactured on or after June 10, 2006 that produce images 
1476  using a fluoroscopic image receptor, the following information is required by 21 CFR 
1477  1020.30(h)(5) and must be provided in a separate, single section of the users instruction 
1478  manual or in a separate manual devoted to this information: 
1479  (i) For each mode of operation, a description of the mode and detailed instructions on how 
1480  the mode is engaged and disengaged.  The description of the mode shall identify those 
1481  technique factors and system controls that are fixed or automatically adjusted by selection of 
1482  the mode of operation, including the manner in which the automatic adjustment is 
1483  controlled. This information shall include how the operator can recognize which mode of 
1484  operation has been selected prior to initiation of x-ray production. 
1485  (ii) For each mode of operation, a descriptive example(s) of any specific clinical 
1486  procedure(s) or imaging task(s) for which the mode is recommended or designed and how 
1487  each mode should be used. Such recommendations do not preclude other clinical uses. 
1488  For additional information on requirements for these image receptors, see FDAs guidance 
1489  entitled Guidance for the Submission of 510(k)s for Solid State X-ray Imaging Devices.21 
1490   
1491  90. QUESTION:  Would it be permissible to control a light localizer with two switches performing 
1492  the following functions:  
1493   
1494  a.  When switch number 1 is activated, the light intensity is equal to about 100 lux at 100 
1495  cm; and  
1496  
1497  b.  When both switches are activated, the light intensity is equal to about 160 lux at 100 cm, 
1498  and it is timed so that after 30 seconds, the intensity decreases to about 100 lux?   
1499   
1500  Would such a system meet the requirement in 21 CFR 1020.31(d)(2)(ii)?  
1501   
1502  ANSWER:  No.  21 CFR 1020.31(d)(2)(ii) requires that whenever the light localizer is 
1503  activated, the intensity must be equal to or greater than 160 lux at 100 cm or the maximum SID, 
1504  if less than 100 cm.  
1505   
1506  91. QUESTION:  21 CFR 1020.31(d)(2)(ii) and 21 CFR 1020.31(d)(2)(iii) place requirements on 
1507  the intensity and edge contrast that must be provided when light field localizers are incorporated 
1508  into general purpose x-ray systems.  What requirements, if any, are applicable to special 
1509  purpose x-ray systems such as mammography, podiatry, and cephalometric systems 
1510  incorporating light localizers? 
1511   
1512  ANSWER:  The answer depends on how the light field is used.  If the light field device is 
1513  intended for use only as a centering light and is not intended by the manufacturer or perceived 
1514  by the user as visually defining the perimeter of the x-ray field, then no specific illumination 
                                                 
21 https://www.fda.gov/ucm/groups/fdagov-public/@fdagov-meddev-gen/documents/document/ucm073781.pdf 
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1515  intensity or light field contrast requirements apply.  However, if the light field is intended for 
1516  use by the manufacturer or perceived by the user to visually define the perimeter of the x-ray 
1517  field, then the illumination intensity requirement of 21 CFR 1020.31(d)(2)(ii) and the light field 
1518  edge contrast requirements of 21 CFR 1020.31(d)(2)(iii) are applicable. 
1519   
1520  (5)  Mechanical Tomographic Systems 
1521   
1522  92. QUESTION:  Traditionally, a tomographic attachment for a standard radiographic x-ray system 
1523  consists of a mechanical interconnecting arm, a drive system, and electrical switches, one of 
1524  which initiates exposure and another of which terminates the exposure.  Thus, the tomographic 
1525  device becomes an exposure timing device.  However, its accuracy may be suspect because of 
1526  mechanical friction or accuracy of attachment by the user.  
1527   
1528  If the exposure termination switch is removed, the exposure timing function would revert to 
1529  the x-ray control, to be set by the user.  Would the tomographic attachment then no longer be 
1530  a certifiable component?  
1531   
1532  ANSWER:  Yes.  
1533   
1534  93. QUESTION:  A manufacturer markets a mechanical tomographic kit to be added to its x-ray 
1535  table.  However, since the kit is capable of controlling exposure time, it is subject to the 
1536  Performance Standards.  The manufacturers instructions specify that the console timer must be 
1537  set to terminate the exposure before the exposure switch in the tomographic attachment would 
1538  terminate it, thus making the tomographic exposure control serve merely as a back-up.  
1539  Therefore, the manufacturer concludes that the tomographic timer would not need to be 
1540  certified.  Would this be a satisfactory approach?  
1541   
1542  ANSWER:  No.  Tomographic attachments that control the exposure time are required to be 
1543  certified (21 CFR 1020.30(a)(1)(i)(A)).  This is true even of tomographic controls used as back-
1544  up timers.  See also question 7. 
1545   
1546  94. QUESTION:  Are exposures made during the operation of radiographic systems in a 
1547  tomographic mode subject to the reproducibility and linearity requirements of 21 CFR 
1548  1020.31(b) and (c)?  
1549   
1550  ANSWER:  Yes.  The reproducibility and linearity provisions of 21 CFR 1020.31(b) and (c) are 
1551  applicable during the tomographic mode of operation.   
1552   
1553  (6)  Source-image receptor distance (SID) Indicators  
1554   
1555  95. QUESTION:  21 CFR 1020.31(e)(1) states that means shall be provided to indicate when the 
1556  axis of the x-ray beam is perpendicular to the plane of the image receptor, to align the center of 
1557  the x-ray field with respect to the center of the image receptor to within 2 percent of the SID, 
1558  and to indicate the SID to within 2 percent.  A manufacturer proposes meeting the requirement 
1559  for indicating SID by placing microswitches at discrete operating locations and providing: (1) 
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1560  user instructions specifying the position of each microswitch and the corresponding SID to the 
1561  permanently-mounted image receptor, and (2) installation of an exposure ready light on the 
1562  beam-limiting device.  This light would only be illuminated when a microswitch is activated.  
1563  The microswitches are frequently used to provide discrete SIDs with a wall-mounted image 
1564  receptor, and are occasionally used to provide discrete SIDs with an under-table image receptor.  
1565  Would such a configuration satisfy the applicable requirements? 
1566   
1567  ANSWER:  No.  A statement of the SID(s) in the user instructions alone is not sufficient.  All 
1568  stationary general purpose radiographic systems must be equipped with means to provide 
1569  numerical indication of any and all SIDs (21 CFR 1020.31(e)(1)) at which the system is 
1570  designed to operate when the x-ray beam is perpendicular to the plane of the image receptor.  
1571  The SID value must be indicated on the system (21 CFR 1020.31(e)(2) and (3)).   
1572   
1573  (7)  Timers (See also questions 92 and 93) 
1574   
1575  96. QUESTION:  A firm wants to manufacture and sell replacement electronic timers for 
1576  installation into existing x-ray controls.  Are there any specific requirements for these timers? 
1577   
1578  ANSWER: Yes.  FDA considers such timers to be x-ray controls (21 CFR 1020.30(a)(1)(i)(A)) 
1579  and, as such, must be certified (21 CFR 1020.30(c)).  Replacement timers require adequate 
1580  labeling, statements of accuracy, and compatibility information (21 CFR 1020.30(g)).  The 
1581  labels must be legible and readily accessible to view when the product is fully assembled (21 
1582  CFR 1010.2 and 1010.3).  See also question 20. 
1583   
1584  (8)  Tube Housing Assemblies (See also questions 12 and 34) 
1585   
1586  97. QUESTION:  A manufacturer produces a number of x-ray tube housing assemblies to be used 
1587  solely for testing purposes and never to be used on patients.  The manufacturer also has tube 
1588  housing assemblies that are used in trade show displays that will never be sold for patient use 
1589  and are not intended to be connected to produce x rays.  Does the manufacturer have to certify 
1590  these tube housing assemblies? 
1591   
1592  ANSWER:  No.  The intent of electronic product certification for x-ray systems and 
1593  components is to assure that patients and users are protected from unnecessary electronic 
1594  product radiation.  Since these tube housing assemblies will not be used to irradiate any part of 
1595  the human body for the purpose of diagnosis or visualization, then they are not considered 
1596  major components of a diagnostic x-ray system (21 CFR 1020.30(b)) and they do not have to be 
1597  certified.  FDA recommends that manufacturers mark the tube housings clearly as to their 
1598  intended purpose, make them non-functional, or include assembly instructions to indicate that 
1599  the tube housings are not to be used on patients. 
1600   
1601  98. QUESTION:  The Performance Standards limiting x-ray leakage (21 CFR 1020.30(k)) and 
1602  capacitor discharge system standby radiation (21 CFR 1020.31(l)) apply to the diagnostic 
1603  source assembly, which includes the tube housing assembly (THA) and the BLD).  How does a 
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1604  manufacturer who wishes to certify only a BLD or THA perform certification testing on this 
1605  component?  
1606   
1607  ANSWER:  The manufacturer must ensure that the THA or BLD it is certifying is compatible 
1608  with the components with which it is intended to be used (21 CFR 1020.30(g)).  This firm, or 
1609  the manufacturer of the other components (if the components are manufactured by different 
1610  firms), must test the THAs or BLDs with those devices with which compatibility is specified 
1611  (21 CFR 1020.30(g)).  Such specifications may describe pertinent physical characteristics of the 
1612  components and/or may list by manufacturer model number the components which are 
1613  compatible.  A firm which specifies compatibility with other components should perform 
1614  periodic direct testing of the component combinations to confirm continuing compatibility.  
1615  Once established, compatibility may be specified in terms of manufacturer name and model 
1616  number or in terms of generic physical characteristics.  See also question 8. 
1617   
1618  99. QUESTION:  If a manufacturer replaces a tube insert in a THA, does it need to change the date 
1619  of manufacture on the THAs identification label?  What about any other required labeling on 
1620  the housing?   
1621   
1622  ANSWER:  Yes.  With the exception of quick-change tubes, replacing the tube insert in a THA 
1623  requires that the THA show a new date of manufacture (21 CFR 1020.30(e)(1), (e)(2) and 
1624  (e)(3)).  The previous label must be removed, covered, or defaced so that only the new date is 
1625  shown (21 CFR 1020.30(e)(2)).  In the event that any other information is different, such as 
1626  name and address of manufacturer or model or serial number, this information also must be 
1627  changed in the same manner (21 CFR 1020.30(e)(1), (e)(2) and (e)(3)).  See also question 34. 
1628   
1629  100. QUESTION:  Does the answer to question 99 (above) change if the system contains a single-
1630  labeled group of components that includes the tube housing assembly that is to be re-loaded? 
1631   
1632  ANSWER:  If there is a single-labeled group of components that includes a tube housing 
1633  assembly that needs replacement, then there are two options: 
1634   
1635  a.  Re-label the single-labeled group of components (date of manufacture, model number 
1636  and serial number if applicable, tube insert model information and change of certifying 
1637  manufacturer if applicable) to meet 21 CFR 1020.30(e)(1).  The date used should be the 
1638  date of replacement of the tube insert, not the original date of manufacture.  (21 CFR 
1639  1020.30(e)(2)).   
1640   
1641  b.  If adding the tube insert does not affect any aspect of compliance, an additional label 
1642  may be used to provide tube insert model information and change of manufacturer if 
1643  applicable. 
1644   
1645  101. QUESTION:  Do repairs to a tube housing assembly, including repairs that require the 
1646  temporary removal and reinstallation of the same insert, constitute the manufacture of a new 
1647  tube housing assembly?  
1648   
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1649  ANSWER:  No.  Any repair done on any tube housing assembly that does not include insertion 
1650  of a different tube insert in a previously certified tube housing is considered repair (21 CFR 
1651  1020.30(d)(2)(iii)) and does not constitute the manufacture of a new tube housing assembly.  
1652  However, any time that the integrity of the THA shielding has been compromised, FDA 
1653  recommends that evidence be provided to the user to assure continued compliance of the tube 
1654  housing assembly with leakage and compatibility requirements. 
44