Form Approved: OMB No. 0910-0025

Expiration Date: February 28, 2026

FORM FDA 3639 (04/23)

Guidance for the Submission of Cabinet X-Ray System 

Reports Pursuant to 21 CFR 1020.40 

Public reporting burden for this collection of information is estimated to average 24 hours per 

response, including the time for reviewing instructions, searching existing data sources, gathering and 

maintaining the data needed, and completing and reviewing the collection of information. Send comments 

regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to:

Department of Health and Human Services 

Food and Drug Administration 

Office of Chief Information Officer 

Paper Reduction Act (PRA) Staff 

PRAStaff@fda.hhs.gov

*Please do NOT send your completed document to this PRA Staff email address.*

An agency may not conduct or sponsor, and a person is not required to respond to, a collection 

of information unless it displays a currently valid OMB control number.
This guidance was written prior to the February 27, 1997 implementation of FDA’s 

Good Guidance Practices, GGP’s. It does not create or confer rights for or on any person 

and does not operate to bind FDA or the public. An alternative approach may be used if 

such approach satisfies the requirements of the applicable statute, regulations, or both. 

This guidance will be updated in the next revision to include the standard elements of GGP’s.

More industry guidance and assistance can be found at the FDA homepage, see: 

http://www.fda.gov/Radiation-EmittingProducts/.

Send your completed report to:

CENTER FOR DEVICES AND RADIOLOGICAL HEALTH 

DOCUMENT MAIL CENTER – WO66-G609 

ATTN: ELECTRONIC PRODUCT REPORTS 

10903 NEW HAMPSHIRE AVENUE 

SILVER SPRING, MD 20993-0002

Questions about reporting and suggestions for changes to this guide may be sent to the above 

address or may be discussed by calling 1-800-638-2041.

FORM FDA 3639 (04/23)
GUIDANCE FOR THE SUBMISSION OF 

CABINET X-RAY SYSTEM REPORTS PURSUANT 

TO 21 CFR 1020.40

Compiled by: 

Division of Compliance 

X-Ray Products Branch

FEBRUARY 1975

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Food and Drug Administration 

Center for Devices and Radiological Health 

Silver Spring, MD 20993

FORM FDA 3639 (04/23)
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FORM FDA 3639 (04/23)
Foreword

The Office of Compliance, Center for Devices and Radiological Health (CDRH) developed this guide. This guide will 

assist manufacturers1 of electronic products which emit radiation in providing adequate reporting of radiation safety testing 

and compliance with federal performance standards. Title 21 of the Code of Federal Regulations (CFR), Parts 1002 and 

1003 specify Reporting and Notification requirements2,3.

Reports submitted on radiation safety of electronic products must follow the appropriate guide (21 CFR 1002.7). If the 

report does not follow an applicable guide it must contain a sufficient justification for any deviations. The submitter of 

the report will receive an acknowledgment letter with the accession number we assign to the report. Please reference this 

accession number in the future when providing additional information about this model family in either a supplement or the 

annual report. If a report is incomplete or inadequate CDRH may reject it and return it for completion. CDRH will not 

enter a rejected report into our database. Also, a rejected report will not receive an accession number.

WE DO NOT APPROVE THESE REPORTS OR THE PRODUCTS BEING REPORTED. It is the manufacturer’s 

responsibility to certify that their products comply with all applicable standards (21 CFR 1010 - 1050), based on a testing 

program in accordance with good manufacturing practices. Prior to the shipment of products in interstate commerce 

21 CFR 1002 requires the manufacturer to submit the report and to comply with all applicable importation requirements 

(21 CFR 1005). If there are deficiencies, we may disapprove the firm’s quality control and testing program, determine 

that the product contains a radiation defect, or determine that the product fails to comply with a standard. We will notify 

the manufacturer if we make such a determination. CDRH may require the manufacturer to cease introduction into U.S. 

commerce until deficiencies are corrected, and to initiate a corrective action program (21 CFR 1003 - 1004) for products 

already introduced into commerce.

Please mail your reports to the address below (FDA can not process electronic submissions at this time). Provide the 

original report with appropriate signature(s) (no facsimiles, please). Provide extra copies only if this guide specifically 

requires them. Submit the report written in the English language. Translate any text that appears in a language other than 

English into English in a complete and accurate manner. Keep a copy of the completed reports in your records.

We are making our reporting guides and other regulatory information available on the Internet under 

http://www.fda.gov/Radiation-EmittingProducts/. No copyright exists for these guides. Reproduce these guides as needed. 

If you would like to comment on the reporting guides, web site, or future electronic submissions, you may direct the comments 

to the address below. If you need additional regulations for electronic products or medical devices, you should contact the 

Division of Small Manufacturers, International and Consumer Assistance by telephone at 1-800-638-2041 or by facsimile at 

301-847-8149.

Sincerely yours,

Lillian J. Gill

Director

Office of Compliance

E-MAIL ADDRESS: dsmica@fda.hhs.gov

MAILING ADDRESS (see 21 CFR 1002.7 for further information):

CENTER FOR DEVICES AND RADIOLOGICAL HEALTH 

DOCUMENT MAIL CENTER – WO66-G609 

ATTN: ELECTRONIC PRODUCT REPORTS 

10903 NEW HAMPSHIRE AVENUE 

SILVER SPRING, MD 20993-0002

1 Manufacturer (see 21) CFR § 1000.3(n)) means any person engaged in the business of manufacturing, assembling, or importing electronic products. 

2 Accidental Radiation Occurrences: 21 CFR 1002.20 requires manufacturers to immediately report accidental radiation occurrences (see 21 CFR 

1000.3(a) for the definition).

3 Notification: Title 21 CFR Part 1003 requires manufacturers to provide Notification of Defects or Failure to Comply. Send these notifications to the 

above address.

FORM FDA 3639 (04/23)
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FORM FDA 3639 (04/23)
FOREWORD

This document is intended to serve as a guide to assist manufacturers in 

the submission of initial and supplements to initial reports for cabinet x-ray 

systems (21 CFR 1020.40). The format selected for this guidance is that of 

report form. It may be used directly or it may serve as a model for developing 

a reporting form. However, if a manufacturer develops his own report form he

must be sure that all information requested by the "model" form is included and 

keyed to this format since this information has been interpreted by the Division 

of Compliance as being necessary to satisfy, in whole or in part, the initial 

and supplemental reporting requirements. In order to standardize reports and facilitate 

their review the order and organization of the model form should be followed as 

closely as possible.

i

FORM FDA 3639 (04/23)
CONTENTS

Page

FOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i

GENERAL INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

CABINET X-RAY SYSTEM REPORTING FORM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Part I - Manufacturer and Report Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Part II - Product Identification and Technical Information . . . . . . . . . . . . . . . . . . . . . 2

A - Model Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

B - Technical Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Part III - Basic Sampling and Testing Information . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

ATTACHMENT LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

APPENDIX A - DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

ii

FORM FDA 3639 (04/23)
GENERAL INSTRUCTIONS

The attached model form is to be used when submitting initial reports and 

supplements to initial reports. Definitions of these types of reports and of 

several other items necessary to properly complete the form are given in Appendix 

A. Part I of the form covers manufacturer and report identification, Part II 

covers product identification and technical information, and Part III covers 

the basic sampling and testing program. The form contains specific instructions for the 

completion of each part. General instructions for the preparation and submission of the 

various types of reports are given below.

1. One copy of Part I of the form is to accompany each report submission.

2. Initial Reports - Information being submitted to meet the requirements of 

an initial report will require completion of all parts of the form. A copy of Part 

II (A), Part II (B) and Part III is to be completed for each model cabinet x-ray 

system.

3. Supplemental Reports - Any changes in information previously submitted 

in Part II (A), Part II (B) or Part III of this form is to be submitted as 

a supplement to an initial report. Only the portions of each part 

undergoing change need be submitted. The date and accession number of the initial 

report to which the supplement applies is to be listed in item 3 of 

Part I.

4. Attachments - Throughout the guide reference is made to attachments. 

These attachments should be clearly marked according to the alphabetical 

letter indicated in the guide. All attachments should be placed in order 

at the end of the guide and the accompanying attachment list filled in. 

The manufacturers may reference their own data identification numbers on 

this list.

5. All reports are to be submitted to:

CENTER FOR DEVICES AND RADIOLOGICAL HEALTH 

DOCUMENT MAIL CENTER - WO66-G609 

ATTN: ELECTRONIC PRODUCT REPORTS 

10903 NEW HAMPSHIRE AVENUE 

SILVER SPRING, MD 20993-0002

iii

FORM FDA 3639 (04/23)
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FORM FDA 3639 (04/23)
Center for Devices and Radiological Health 

Document Mail Center - WO66-G609 

Electronic Product Reports 

10903 New Hampshire Avenue 

Silver Spring, MD 20933-0002

Cabinet X-ray System Reporting Form

Part I - Manufacturer and Report Identification

This part of the form is to accompany each submission. Only one copy of this part need 

be completed even though more than one copy of other parts of this form may be required 

to provide all the information being reported.

1. Manufacturer:

Name

Address

Corresponding Official: (May not be applicable for imports)

Signature

Name

Title

Telephone Email

2. Importer: (Complete if applicable)

Name

Address

Corresponding Official:

Signature

Name

Title

Telephone Email

3. Report Type:

Initial

Supplement to initial report, CDRH

Accession No. submitted on

(dates)

4. Report Date:

1

FORM FDA 3639 (04/23)
Part II - Product Identification and Technical Information

Complete Sections A and B for each new cabinet x-ray system being reported. A copy of 

Section A and B is to be completed for each new cabinet x-ray system being reported. 

Only Section A need be completed to report additional brand and/or selling model 

numbers of a system when all other manufacturing and testing information is the same as 

previously submitted. Any information covered in Part II (B) and/or Part III of the form 

that has not been previously reported should be provided in the applicable portions of 

Part II (B) and/or Part III.

A. Model Identification

1.0 Product Type:

Reported pursuant to paragraph c of 1002.61

- check as applicable -

Product Type

Radiographic, conventional source

Radiographic, pulsed or flash source

Fluoroscopic

Radiographic and fluoroscopic

Screening device used in public facilities 

(such as baggage inspection devices)

Other than specified types (describe below)

Description of other product types:

2.0 List the name and model number of the product manufactured or 

imported to which the cabinet x-ray standard is applicable. Do not 

report if the item is intended solely for export to countries whose 

applicable requirements are met.

Name of Product

Model Number

3.0 If the reported model is sold under brand names, other than those 

of the manufacturer, please provide the brand name, model number, 

and name and address of each company under whose name the model 

is sold.

Brand Name

Model Number

2

FORM FDA 3639 (04/23)
Company

Address

4.0 List all uses or applications for which the model is intended.

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

5.0 Reference Verification (check one)

5.1 All information previously reported in CDRH Accession 

No. on (date) is applicable to the 

models listed under item 2, Part II (A) of this report. The models 

will be manufactured and tested in accordance with the procedures 

reported in the reference document.

5.2 Except as specifically indicated in Section B of Part II 

and/or Part III, all information previously reported in CDRH 

Accession No. on (date) is 

applicable to the models listed under item 2, Part II (A) of this 

report. These models will be manufactured and tested in 

accordance with the procedures reported in the referenced 

document(s).

5.3 This is the initial submission of information required 

for cabinet x-ray system(s).

B. Technical Information

1.0 X-ray Emission

1.1 Is the system designed to limit x-ray emission from the 

cabinet x-ray system to an exposure of 0.5 milliroentgen in any 

one hour at a point of five centimeters outside the external 

surface?

Yes No

3

FORM FDA 3639 (04/23)
1.2 List the following characteristics of the x-ray system:

range of kVp adjustment

range of mA adjustment

duty cycle (see definition)

range of timer adjustment

total filtration

beam divergence

beam orientation

1.3 Describe the type, thickness, and location of shielding 

incorporated into the product to limit x-ray emission at the 

external surface. Provide illustrative drawings as attachment A.

1.4 Describe all service adjustments and procedures that affect 

radiation leakage.

1.5 Are any doors included as part of the cabinet x-ray 

system?

Yes No

If no, proceed to section 1.6. If yes, complete the following.

1.5.1 Describe the intended purpose of each door.

Describe:

4

FORM FDA 3639 (04/23)
1.6 Are any access panels included as part of the cabinet x-ray 

system?

Yes No

If no, proceed to section 2.0. If yes, complete the following.

1.6.1 Describe the intended purpose of each access 

panel.

Describe:

2.0 X-ray Controls and Indicators (Provide a circuit diagram as 

attachment B).

2.1 Describe the control device(s) for initiating and 

terminating x-ray generation and the physical location(s). 

Include the method by which x-ray exposure interruption is 

accomplished (e.g., release of exposure switch, termination 

of preset time, etc.) and the method of resuming operation 

following x-ray generation interruption by the control 

device(s).

Describe:

2.2 Describe the characteristics, operation, and location of the 

main power control.

5

FORM FDA 3639 (04/23)
2.3 Describe the characteristics, operation, and location of the 

key activated control. Include a statement of the key capture 

condition.

2.4 Can an x-ray exposure greater than a period of one-half 

second be made with this cabinet x-ray system?

Yes No

2.4.1 If yes, are means provided to enable the operator to 

terminate the exposure prior to completion of the preset 

exposure period? Yes No

2.4.2 If no, are means provided to prevent an additional 

x-ray exposure to be made? Yes No

2.5 Describe all devices that indicate when and only when 

x-rays are being generated and that can be viewed from any 

location where x-ray generation can be initiated. Include 

dimensions, location, and labeling.

Describe:

2.6 How long are indicators actuated when the x-ray generation 

period is less than one-half second?

2.7 Does failure of any single component of the cabinet x-ray 

system cause failure of more than one x-ray production 

indicator?

Yes No

2.8 Describe all other means which indicate when x-rays 

are being generated that can be viewed from any door, 

access panel, and port. Include dimensions, location, and 

labeling.

Describe:

6

FORM FDA 3639 (04/23)
2.9 Is the cabinet x-ray system designed to admit humans?

Yes No

If no, proceed to section 3.0. If yes, complete the following.

2.9.1 Describe all exposure controls within the cabinet and 

include them in the diagram provided as attachment B.

Describe:

2.9.2 Is a method provided to reset, override, or bypass the 

controls described in 2.9.1 from outside the cabinet?

Yes No

2.9.3 Describe the audible and visible warning signals 

provided in the cabinet.

Describe:

2.9.4 How long are the warning signals activated prior to 

the first initiation of x-ray generation after closing any door 

or access panel designed to admit humans?

.

2.9.5 If any single component of the cabinet x-ray system 

fails, can x-rays be produced without either the audible or 

visible warning systems indicating x-ray production?

Yes No

7

FORM FDA 3639 (04/23)
2.9.6 Does a visible signal within the cabinet remain 

activated for the entire period of x-ray generation?

Yes No

2.9.7 Provide copies (or replicas) of all signs that are 

illuminated within the cabinet which explain the 

meanings of the warning devices. Indicate the sign 

location with pictures and/or drawings. Label these as 

attachment C.

3.0 Safety Interlocks.

3.1 Describe the interlock system and provide circuit 

diagrams showing interlocks and safety systems for each 

door and each access panel.

The circuit diagrams may be included in attachment B or 

provided separately as attachment D. Include the electrical 

and mechanical characteristics of each interlock device in 

the description.

Description:

3.2 Describe any provisions for adjustment of the interlocks.

3.3 Indicate the amount of door or access panel movement that is 

possible prior to actuation of the interlock.

3.4 Is any part of the circuit physically removed from the 

energy supply circuit to the high-voltage generator when a door 

is opened.

Yes No

3.5 Is such disconnect dependent upon any moving part other 

than the door. Yes No

Provide drawings, sketches or engineering drawings to clearly 

illustrate operation as attachment E.

8

FORM FDA 3639 (04/23)
3.6 Describe how x-ray production can be resumed after any

safety interlock has been activated.

Describe:

3.7 Are the required interlock circuits designed to ensure that 

the failure of one component does not result in the failure of 

more than one required safety interlock?

Yes No

3.8 Provide a circuit analysis describing the effects of critical 

component failure on the interlock system. Label the analysis 

Attachment F.

4.0 Warning, Certification, and Identification Labels.

4.1 Provide an exact replica of all labels which show any of 

the following.

(a) The certification statement,

(b) the name and address of the manufacturer (or individual or 

company under whose name it is sold),

(c) the date and place of manufacturer (these should be spelled 

out in full), and

(d) the model number and serial number.

Label the replicas as attachment G.

4.1.1 Is this labeling permanently affixed to or inscribed on 

the system and legible and accessible to view when the 

system is fully assembled for use?

Yes No

4.2 Is a warning label affixed at the location of any control 

which can be used to initiate x-ray generation?

Yes No

4.2.1 Is this warning label permanently affixed to or 

inscribed at the location of the control, legible and 

accessible to view?

Yes No

4.2.2 Provide a copy of the warning label affixed at the 

control(s) and label it attachment H.

9

FORM FDA 3639 (04/23)
4.3 Describe all other warning labels and their locations and 

include copies of the labels as attachment I.

Describe:

5.0 Ports and Apertures

5.1 What are the shapes and dimensions of all entrance and exit 

ports?

# Shape Dimensions

1.

2.

3.

4.

5.

6.

5.2 What is the shortest distance from the primary beam to 

any location in the plane or perimeter of any entrance or exit 

port? (Numbers indicate same ports as in 5.1)

Distance

1.

2.

3.

4.

5.

6.

10

FORM FDA 3639 (04/23)
5.3 Describe all means specifically provided as part of the 

cabinet x-ray system to prevent insertion of any part of the body 

through a port into primary beam.

Describe:

5.4 What are the shapes and dimensions of all apertures?

# Shape Dimensions

1.

2.

3.

4.

5.

6.

5.5 What is the purpose of each of these apertures? 

(Numbers indicate same apertures as in 5.4)

1.

2.

3.

4.

11

FORM FDA 3639 (04/23)
5.

6.

5.6 Describe the means provided to prevent the insertion of any part 

of the human body through these apertures. (Numbers indicate the 

same apertures as in 5.4)

Means:

1.

2.

3.

4.

5.

6.

12

FORM FDA 3639 (04/23)
6.0 Floors of the Cabinet X-ray Systems.

6.1 Does the design of the cabinet x-ray system depend upon 

the purchaser providing a support surface that becomes the 

floor of the system when installed?

Yes No

6.2 If the answer to 6.1 is yes, describe these installation 

requirements.

Describe:

6.3 Does the installation described in 6.2 constitute a 

permanent installation?

Yes No

7.0 Ground Fault.

7.1 Can a ground fault result in generation of x-rays?

Yes No

7.2 Provide a ground fault analysis as attachment J.

8.0 Include a copy of the information packet on safety, installation, and 

maintenance procedures, which is supplied to users as required by 1020.40 

(c) (9) of the standard for each model, as attachment K.

9.0 Provide copies of any additional operating instructions, published 

product technical data sheets, specifications sheets, applications notes, or 

other published material relating to product specifications, applications, 

radiation emission or radiation safety, as attachment L. A picture or 

drawing of each product should also be included. Promotional sales 

literature may be included, if appropriate.

10.0 Systems designed primarily for screening of hand-carried items in 

public facilities.

13

FORM FDA 3639 (04/23)
10.1 Describe means provided to require operator presence at 

the control area during generation of x-radiation.

Describe:

10.2 Do the means described in 10.1 permit surveillance of all 

ports and doors?

Yes No

10.2.1 If no, explain

10.3 Do the means described in 10.1 permit the operator to 

terminate x-ray generation at any time?

Yes No

10.3.1 If no, explain

14

FORM FDA 3639 (04/23)
Part III - Basic Sampling and Testing Information

A. Direct Testing

1.0 Briefly explain the concept of each direct x-ray measurement test that is 

done to verify compliance with the emission limit of the standard. Include in this 

explanation a copy of the test method(s). Label the explanation and test methods 

as attachment M.

The test described shall include, but not be limited to:

a. Testing to evaluate effects of scattering object and placement,

b. Testing to evaluate x-ray emission prior to interruption of x-ray 

generation through operation of any required safety interlock,

c. Testing to evaluate the effects on shielding from shipping, 

transporting or moving the cabinet system,

d. Testing to evaluate line voltage fluctuations and critical component 

deterioration,

e. Testing to evaluate effects of service adjustments and procedures,

and

f. Final acceptance testing.

2.0 At what stage(s) (i.e., engineering prototype, initial production lot 

run, production run installation, etc.) in the design, production, or 

installation of the cabinet x-ray system is a direct test made to verify 

compliance with the standard?

# Test Stage

1.

2.

3.

4.

5.

6.

7.

8.

15

FORM FDA 3639 (04/23)
3.0 State the limit(s) at which the unit would be rejected for each 

final acceptance test.

Limit:

4.0 Describe the procedure used to determine the location(s) of 

maximum radiation intensity.

Describe:

5.0 If the direct test utilizes a radiation measurement instrument 

that scans the cabinet x-ray system, what is the rate of scan 

(in cm/sec)?

Rate:

6.0 State the tube potential, current, beam orientation, duty cycle, and scatter 

conditions that will produce the maximum external surface x-ray exposure.

tube potential

current

beam orientation

duty cycle

scatter object

scatter object position

7.0 State the distance (in centimeters) between the external surface and 

the radiation measurement instrument .

16

FORM FDA 3639 (04/23)
8.0 In each stage, described in 2.0, list the percentage or number of 

items tested.

# Stage Percentage or Number

1.

2.

3.

4.

5.

6.

7.

8.

9.

B. Radiation Instrumentation Used for Testing

1.0 Instruments used for radiation measurement.

Instruments

#

Instrument 

#1 Instrument #2 Instrument #3

Manufacturer

Model Number

Type of Instrument

Precision of Instrument

Accuracy of Instrument

Response Time

Energy Dependence

Angular Response

Exposure Rate Dependence

Range

Effective Measurement Area

17

FORM FDA 3639 (04/23)
2.0 Calibration of Instruments

2.1 Interval of time between calibration

2.2 Method of calibration, including accuracy and source 

of calibration

2.3 Verification procedure used to assure proper day-to-day 

operation of instrumentation

C. Indirect Testing

1.0 If the test method used to monitor compliance with the emission 

limit performance requirement is other than the direct measurement 

described above, describe the method and attach a copy of the test 

procedure labeled as attachment N. In addition, provide the basis for the 

indirect method (any method other than a radiation exposure 

measurement); explain why it is an accurate indication of compliance 

with the emission requirements, and submit the technical data which 

supports this conclusion.

2.0 Specify the primary purpose of each indirect test.

# Test Purpose

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

18

FORM FDA 3639 (04/23)
3.0 Specify the stage(s) in the design, production, or installation of 

the system that the indirect test is made.

# Test Stage

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

4.0 For any test whose purpose is acceptance or rejection of the 

system, specify the rejection limit of the product.

# Test Rejection Limit

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

5.0 Specify who has the responsibility for conducting these tests.

Specify:

19

FORM FDA 3639 (04/23)
6.0 For each test conducted for the purpose of acceptance, specify the actual 

number of units tested and the proportion of production output which that number 

represents.

Test # Tested Proportion of Production

D. Sampling

For each production line test performed for the purpose of determining product 

acceptability on less than 100 percent of the output, as attachment O, answer the 

following:

1. Specify the sampling plan used and provide the parameters of the plan (i.e., 

lot size, sample size, acceptance criteria, etc.). If the sampling plan is obtained 

from a set of standard sampling tables, indicate the source and type 

of plan. If the sampling plan was designed specifically for this application, 

indicate the requirements which were established for the plan and the 

assumptions used, and whether acceptance criteria is based upon attributes or 

variables.

2. Describe the procedure used for selecting the sample and indicate how 

randomness is assured.

3. For each test or inspection specify the quality characteristics and the 

specification limit(s) by which acceptable quality is distinguished from 

unacceptable.

4. Provide the operating characteristic (O.C.) curve of the sampling plan.

5. Specify the distribution assumed and the procedures used for computing 

acceptance probabilities for the O.C. curve of the sampling plan.

6. Specify the producer's and consumer's risk of the sampling plan and indicate 

at what quality level each applies.

7. Describe the action taken if the sampling plan leads to a rejection 

decision.

E. Critical Component Testing

As attachment P, answer the following:

1. Describe all applicable quality control and testing procedures for critical 

components conducted prior to installation of the components into your 

product which you consider a necessary and vital part of your testing 

program to assure compliance with the Federal Performance Standard. This 

shall include, but not be limited to, incoming inspection and/or subassembly testing of such items as x-ray sources, pressure pads, interlock 

switches, relays and shielding components. Where applicable, the 

description shall include:

20

FORM FDA 3639 (04/23)
a. Vendor qualification requirements.

b. Incoming inspection procedures, accept/reject criteria, and 

lot and sample size if not 100 percent tested. If 100 percent 

tested, so state.

c. Corrective action following unit or lot rejection.

2. Describe all applicable life testing procedures on the x-ray system or on 

those critical components incorporated into the x-ray system which you 

consider a necessary and vital part of your testing program to assure 

compliance with the Federal Performance Standard for the life of the 

product. This description shall include, but not be limited to, the following 

information:

a. The state(s) in the development or production of a specific

model or design when life testing is conducted on the system or 

critical component.

b. A copy of the life testing protocol, including the test 

method used. If previously addressed, reference may be made to 

your response to other appropriate sections of your report.

c. The period of time (e.g., years) relative to use of the unit at 

an installed site which the life testing represents.

F. Test Results: As appendix Q, provide:

1.0 The results of Quality Control testing to date as follows:

1.1 The numerical results of the direct radiation tests upon which you base 

your certification, including: a) date of the test, b) state of 

development, production or installation at which the test was made.

1.2 A summary of the numerical results of direct and/or indirect quality 

control tests of production line units.

1.3 Where sufficient data are available, the mean, range, and standard 

deviation of each type of measurement. If these values are 

unavailable, other representative statistics or expressions or results may 

be reported.

2.0 Summary results of tests performed to determine "worst case" 

conditions for x-ray emission at the external surface of the cabinet x-ray

system.

3.0 Summary of results of critical component testing.

4.0 Summary of results of critical component or system life testing.

5.0 Describe changes in critical components occurring with time that affect 

the performance of the unit with respect to applicable performance

requirements.

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FORM FDA 3639 (04/23)
ATTACHMENT LIST

(check all that are attached including any added to provide information not specifically 

identified below)

Attachment Checkbox 

Status

Manufacturer's Own Data 

Identification Number

A. Shielding Drawings

B. Circuit Diagrams

C. Signs Within the Cabinet

D. Interlock System-Circuit Diagram

E. Drawings of Disconnect Interlock

F. Analysis of Interlock System 

Component Failure

G. Certification and Identification 

Labels

H. Control Warning Labels

I. Other Warning Labels

J. Ground Fault Analysis

K. User Information

L. Other Information and Data

M. Direct Test Methods

N. Indirect Testing

O. Sampling

P. Critical Component Testing

Q. Test Results

Note: This sheet, completed as applicable, is to accompany each report.

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FORM FDA 3639 (04/23)
Appendix A - Definitions

The definitions of report types and several other terms given below are provided for use 

with the general guidance to assure proper completion of the attached model form and 

satisfaction of reporting requirements.

1. Initial Report - The first report from a manufacturer to CDRH on a particular

model of product. It must provide complete information on the manufacturing and testing 

program that a manufacturer is employing.

2. Supplemental Report - A report that provides details of any additions, deletions, 

corrections, or changes to information previously submitted in an initial report. Reports 

of this type are to be designated as supplements to the report (referenced by CDRH 

Accession Number and submission data) where the information being changed was 

previously submitted.

3. "Access panel" means any barrier or panel which is designed to be removed or 

opened for maintenance or service purposes, requires tools to open, and permits access to 

the interior of the cabinet.

4. "Aperture" means any opening in the outside surface of the cabinet, other than a 

port, which remains open during generation of x radiation.

5. "Cabinet x-ray system" means an x-ray system with the x-ray tube installed in an 

enclosure (hereinafter termed "cabinet") which, independently of existing architectural 

structures except the floor on which it may be placed, is intended to contain at least that 

portion of a material being irradiated; provide radiation attenuation, and exclude 

personnel from its interior during generation of x radiation. It would include all x-ray 

systems designed primarily for the inspection of carry-on baggage at airline, railroad, and 

bus terminals, and in similar facilities. An x-ray tube used within a shielded part of a 

building, or x-ray equipment which may temporarily or occasionally incorporate portable 

shielding is not considered a cabinet x-ray system.

6. "Door" means any barrier which is designed to be movable or opened for 

routine operation purposes, does not generally require tools to open, and 

permits access to the interior of the cabinet. For the purposes of paragraph (c) (4) (i) 

of this section, inflexible hardware rigidly affixed to the door shall be considered part 

of the door.

7. "Duty cycle" means the amount of time x-rays can be generated or the number of 

x-ray pulses that can be generated in any hour, the limit of which is determined by the 

design of the x-ray system.

8. "Exposure" means the quotient of dQ by dm where dQ is the absolute value of the 

total charge of the ions of one sign produced in air when all the electrons (negatrons and

positrons) liberated by photons in a volume element of air having mass dm are 

completely stopped in air.

9. "External surface" means the outside surface of the cabinet x-ray system, 

including the high voltage generator, doors, access panels, latches, controls knobs,

and other permanently mounted hardware and including the plane across any aperture or 

port.

10. "Floor" means the underside external surface of the cabinet.

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FORM FDA 3639 (04/23)
11. "Ground fault" means an accidental electrical grounding of an electrical 

conductor.

12. "Port" means any opening in the outside surface of the cabinet which is 

designed to remain open, during generation of x-rays, for the purpose of 

conveying material to be irradiated into and out of the cabinet, or for partial insertion 

for irradiation of an object whose dimensions do not permit complete insertion into the 

cabinet.

13. "Primary beam" means the x radiation emitted directly from the target and passing 

through the window of the x-ray tube.

14. "Safety interlock" means a device which is intended to prevent the generation 

of x radiation when access by any part of the human body to the interior of the cabinet 

x-ray system through a door or access panel is possible.

15. "X-ray system" means an assemblage of components for the controlled generation 

of x-rays.

16. "X-ray tube" means any electron tube which is designed for the conversion of 

electrical energy into x-ray energy.

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FORM FDA 3639 (04/23)