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  5. Inspection and Field Testing of Radiation-Emitting Electronic Products: Attachment D: Specific Instructions for Cabinet X-Ray Product Inspections and Tests
  1. Guidance Documents (Medical Devices and Radiation-Emitting Products)

Inspection and Field Testing of Radiation-Emitting Electronic Products: Attachment D: Specific Instructions for Cabinet X-Ray Product Inspections and Tests

Purpose

The Radiation Safety Performance Standard for Cabinet X ray Systems [Title 21 CFR § 1020.40] (performance standard) was designed to protect the public and system operators from unnecessary radiation hazards associated with the use of cabinet x-ray systems. The performance standard sets an exposure emission limit of 0.5 milliRoentgen (mR) in one hour for radiation emitted from a cabinet x ray system. Additional required safety features include interlocks, indicator lights, and warning labels. The performance standard applies to all cabinet x ray systems manufactured or assembled on or after April 10, 1975. Requirements regarding x ray systems designed primarily for the inspection of carry on airline baggage apply to systems manufactured or assembled on or after April 25, 1974.

Specific Instructions

The potential risk from a cabinet x-ray system is dependent on the maximum power that can be delivered to the x-ray tube and the environment in which the system is used. A cabinet x-ray system that can operate at higher peak tube potential and tube current will present a greater potential risk when compared with a lower power cabinet x-ray system. The following is an example of how the use environment affects the potential risk: a cabinet x-ray system used for checking circuit board quality is integrated into an automated production line and very rarely approached by anyone poses a lower potential risk than a carry on baggage security x-ray system which is loaded by members of the public and always has an operator present in close proximity.

Follow the general guidance on inspection, investigation, and field test priorities provided in section II.B.3 above and use your discretion based on the preceding discussion of potential risk. An example inspection checklist of cabinet x-ray specific issues has been included. For further guidance on compliance with specific requirements of the performance standard see the Cabinet X-Ray Compliance Guide (see reference below).

Radiological Health Specialists have been specifically trained in general EPRC requirements and also have specialized training in the cabinet x-ray product performance standards. These specialists should perform cabinet x-ray inspections and field tests, and may train additional field staff or accompany a medical device investigator to conduct joint EPRC/medical device inspections.

When conducting a cabinet x-ray system manufacturer inspection or field test all FDA personnel are required to wear a personal radiation monitor. If you do not have a personal radiation monitor badge, follow the instructions as noted in Part II of this program.

CDRH is responsible for all administrative/regulatory action, regulatory follow up, and for the issuance of all notices of violations to manufacturers of cabinet x-ray systems.

Field Test Instructions

Generally cabinet x-ray field tests should be performed when requested by CDRH, in response to requests from other federal agencies, to check the validity of a trade or consumer complaint, or when it is necessary for confirmation that a manufacturer’s testing program or corrective action plan is adequate.

When performing a cabinet x-ray field test collect data in accordance with the written procedures prescribed in “Routine Compliance Testing for Cabinet X ray Systems to which 21 CFR Subchapter J is applicable, Dated March 1985” (see reference below). If it is determined that the written procedures cannot be followed, describe in detail the variance from the prescribed procedure in the comments section of the test form.

Field Test Equipment: MDH meters are not sufficiently sensitive to detect radiation emissions from a cabinet x-ray system. Use only the meters identified in the field test procedure identified below.

NOTE: Cabinet X-Ray Systems installed at airports are not to be field tested except as requested by CDRH, Transportation Security Administration (TSA), Customs and Border Protection (CBP), or Department of Agriculture (USDA). Usually there will be a manager from the relevant agency at the facility containing the system to be tested. Coordinate the test with the appropriate agency on-site manager. Where the national radiation safety contacts are known they should also be contacted. The national contacts for TSA and CBP are included below:

Contacts for Radiation Safety at other Federal Agencies
NamePhoneEmailPosition
Jill Segraves(571) 227-2292Jill.Segraves@dhs.govRadiation Safety Program Manager, Transportation Security Administration
Richard Whitman(317)614-4843richard.t.whitman@dhs.govRadiation Safety Officer, Customs and Border Protection

Results for all field tests of TSA or CBP cabinet x-ray systems should be sent CDRH, the appropriate contact listed above, and the on-site manager.

References

Frequently Asked Questions on Cabinet X-ray Systems (March 24, 2003)

Compliance Guide for Cabinet X-Ray Systems: Coming soon to the web

Routine Compliance Testing for Cabinet X-ray Systems to which 21 CFR Subchapter J is applicable, Dated March 1985
Refer to the Cabinet X-Ray Systems main page for additional information.

Cabinet X-Ray Product Codes

Translation of 2-Digit Code

Product Name

Product Code

CFR

Definition

Cabinet X-Ray Systems, Non-MedicalCabinet X-Ray, Industrial, Non-Medical

94

RCE

1020.40

A cabinet x-ray system used for quality control, non-destructive testing, or some other industrial purpose.
Cabinet X-Ray Systems, Non-MedicalExplosive Detection Systems, Cabinet X-Ray Systems, Non-Medical

94

RCF

1020.40

A cabinet x-ray system used for detection of explosives in closed containers such as airline baggage. Usually these systems use a non-standard x-ray mode to perform this function such as computed tomography.
Cabinet X-Ray Systems, Non-MedicalSecurity X-Ray (includes Baggage X-Ray), Cabinet X-Ray Systems, Non-Medical

94

RCG

1020.40

A cabinet x-ray system used to examine the contents of containers such as airline baggage, brief cases, and purses to detect weapons or other contraband.
Cabinet X-Ray Systems, Non-MedicalCargo X-Ray, Cabinet X-Ray Systems, Non-Medical

94

RCH

1020.40

A large cabinet x-ray system used to examine pallets full of cargo to find weapons or other contraband.
Cabinet X-Ray Systems, Non-MedicalOther

94

RZZ

1020.40

A cabinet x-ray system used for an unlisted specific purpose.

Classification of Non-compliant Items

Emission Limit
1020.40(c)(1)(i)Exceeds emission limit  
1020.40(c)(1)(i)Radiation emission > 10mR in one hourMajorClass A
1020.40(c)(1)(i)Radiation emission rate ≤ 10 mR in one hour and > 0.5 mR in one hourMajorClass B
1020.40(c)(1)(ii)Emission limit requirements – measurement inadequateMajorSee (c)(1)(i)
Floors
1020.40(c)(2)Floor fails to adequately attenuate radiation emission into occupied area underneath x-ray systemMajorSee (c)(1)(i)
Ports and Apertures
1020.40(c)(3)(i)

It is possible to reach the primary beam through a port

Primary beam greater than 10 R per hour and beam is easy to access

Primary beam greater than 10 R per hour and beam is possible but difficult to access inadvertently

Primary beam less than 10 R per hour and greater than 5 R per hour

Primary beam less than 5 R per hour

 

Major

Major

 

Minor

Concern

 

Class A

Class B

 

Class B

Class C

1020.40(c)(3)(ii)

Aperture allows human access to interior of cabinet

Radiation exposure rate in accessed area greater than 5 R per hour

Radiation exposure rate in accessed area less than 5 R per hour

 

Major

Minor

 

Class B

Class C

Safety Interlocks
1020.40(c)(4)(i)Safety interlock - door does not have any interlock and emission rate with door open is > 10mR in one hourMajorClass A
1020.40(c)(4)(i)Safety interlock - door does not have multiple interlocksMajorClass B
1020.40(c)(4)(i)Neither door safety interlock causes physical disconnect  
1020.40(c)(4)(i)Radiation emission rate with interlock failure and door open > 2 mR per hourMajorClass B
1020.40(c)(4)(i)Radiation emission rate with interlock failure and door open ≤ 2 mR per hour and > 0.5 mR in any one hourMinorClass B
1020.40(c)(4)(i)Safety interlocks - disconnect based on movement other than door  
1020.40(c)(4)(i)Radiation emission rate with interlock failure and door open > 2 mR per hourMajorClass B
1020.40(c)(4)(i)Radiation emission rate with interlock failure and door open ≤ 2 mR per hour and > 0.5 mR in any one hourMinorClass B
1020.40(c)(4)(ii)Lack of safety interlock - access panel and emission rate with access panel open is > 10 mR in oneMajorClass B
1020.40(c)(4)(iii)Safety interlocks - after an interruption reset of the interlock results in resumption of x-ray productionMajorClass B
1020.40(c)(4)(iv)Safety interlocks - single component failure disables more than one interlockMajorClass B
Ground fault
1020.40(c)(5)Ground fault can result in x-ray initiationMajorClass A
Controls and Indicators
1020.40(c)(6)(i)Key control - not providedMajorClass B
1020.40(c)(6)(i)Key control - not functionalMajorClass B
1020.40(c)(6)(ii)Controls to initiate and terminate x-rays other than interlocks or power control are not presentMajorClass B
1020.40(c)(6)(iii)Two independent means of Exposure indication at initiation are not presentMajorClass B
1020.40(c)(6)(iii)Exposure indication - other than milliammeter is not presentMajorClass B
1020.40(c)(6)(iii)Exposure indication at initiation – is not visible from controlMajorClass B
1020.40(c)(6)(iii)Multiple failures of exposure indication caused by a single failureMajorClass B
1020.40(c)(6)(iii)Exposure indication - labeling - X-RAY ON is not presentConcernClass C
1020.40(c)(6)(iii)Exposure indication - labeling - x-ray tube current is not presentConcernClass C
1020.40(c)(6)(iv)Exposure indication required to be visible from a door, panel, or port and is not presentMajorClass B
1020.40(c)(6)(iv)Exposure indication not visible from each door, panel, or portMajorClass B
1020.40(c)(6)(iv)Exposure indication at door, panel, or port is not labeled - X-RAY ONConcernClass C
Additional controls and indicators for systems designed to admit humans
1020.40(c)(7)(i)No means for preventing and terminating x-rays from withinMajorClass A
1020.40(c)(7)(ii)X-rays can be initiated from within the cabinetMajorClass A
1020.40(c)(7)(iii)No Pre-exposure warning within cabinetMajorClass A
1020.40(c)(7)(iii)Pre-exposure warning within cabinet – Warning did not activate at least 10 seconds prior to exposureMajorClass A
1020.40(c)(7)(iii)Pre-exposure warning within cabinet - a single failure causes both audible and visual warnings to failMajorClass A
1020.40(c)(7)(iv)No exposure warning within cabinetMajorClass A
1020.40(c)(7)(v)Lack of signs giving meaning of warning signalsMajorClass B
1020.40(c)(7)(v)Lack of signs giving instructions for use of controls to terminateMajorClass B
1020.40(c)(7)(v)Signs are not legible, accessible, illuminatedMajorClass B
Warning Labels
1020.40(c)(8)(i)Lack of Warning labels - X-rays ProducedConcernClass C
1020.40(c)(8)(ii)Lack of Warning labels - Human AccessConcernClass C
Information to be provided
1020.40(c)(9)(i)Instruction manuals - not providedMinorClass C
1020.40(c)(9)(i)Instruction manuals - inadequate technical & safety informationMinorClass C
1020.40(c)(9)(i)Assembly instructions - required and not providedMajorClass B
1020.40(c)(9)(i)Assembly instructions - not adequate for complianceMajorClass B
Additional requirements for systems loaded by the public (e.g. Baggage inspection)
1020.40(c)(10)X-ray baggage inspection systems (public area) - No means to assure operator presenceMajorClass A
1020.40(c)(10)(i)No means to terminate exposureMajorClass B
1020.40(c)(10)(ii)No means to terminate an exposure sequenceMajorClass B
Modification of a certified system
1020.40(d)Modification – failure to re-certify and re-identifyMajorClass B

Cabinet X-Ray Product Inspection Guidance and Field Test Form

Cabinet X-ray inspection checklist.

This guidance is in addition to the instruction provided in Part III.A.2 of this program. Refer to the Compliance Guide for Cabinet X-Ray Systems (referenced above) for a detailed discussion of the cabinet x-ray system performance standard.

  1. Record Firm Identification, Location, and Contact information
  2. Models
    1. What models does the manufacturer produce?
    2. What models are available for observation of certification testing?
  3. Performance Requirements
    1. Radiation Emission Limit
      Unlike lasers, the “characterization” of the radiation emitted from a cabinet x-ray system is not relevant. The amount of x radiation emitted is critical. Note: The emission limit in the cabinet x-ray standard is for the amount of exposure (less than 0.5 mR) in one hour. It is not a limit on the instantaneous rate of radiation emission.
      1. Is there a written procedure for emission testing?
      2. Are numerical values recorded for the worst case emission from each system?
      3. What instruments are used during emission testing? (Record the model and manufacturer of each radiation meter)
        1. Identify the type of each meter (ideally the mfr. should know the type). A few possible types are: ion chamber, Geiger-Mueller (GM), plastic scintillators.
        2. What is the response time for each meter?
        3. Can the x-ray system produce a beam for longer than the meter’s response time? Does the procedure specify that x-ray will be produced for longer than the meter’s response time?
        4. Is the meter held still at various positions around the x-ray system or is it moved slowly around the system?
          1. If the meter is in motion during an exposure is there a maximum scan speed noted in the procedure?
          2. During the test, is the meter moved slowly enough so that its response time is not a factor?
          3. Is the scan speed limit adhered to by the person performing the test?
          4. Are all the likely points of excess emission checked? If there are emission issues they usually occur at the ports, seems, corners, access panels, and doors.
        5. If the x-ray beam can not be produced continuously can the radiation meter measure an integrated dose?
        6. Does the meter used for the quantitative measurement have a current calibration? What energy was the meter calibrated at? What is the peak tube potential of the cabinet x-ray system?
        7. Does the meter produce a linear response for the expected energy range of emission from the product?
        8. Is the meter sufficiently sensitive in the relevant energy range that it responds to radiation emission from the product?
      4. If there are calculations involved in determining the total amount of exposure in anyone hour are all the steps clearly identified and justified?
      5. What is the rejection limit set by the manufacturer for emissions? If the rejection limit is the same as the limit in the performance standard how is the inherent experimental error in measuring radiation emission from the system accounted for? If less than the limit in the performance standard is it sufficiently restrictive to account for experimental error?
      6. Based on the answers above and observation of the emission test procedure, is the emission testing conducted by the manufacturer sufficient to assure that the product will comply with the performance standard?
    2. Are items placed into the cabinet through a port or through a door?
      1. If items are placed into the cabinet through a port is it necessary for someone to hold the item while it is being exposed to radiation? If so can any part of the body reach the primary beam through the port?
      2. If items are moved into the system on a conveyor belt will any part of the body reach the primary beam during normal operation? (Crawling into the system is not considered normal operations)
      3. If it appears that it is possible to reach the primary beam inadvertently ask the manufacturer for the exposure rate in the primary beam per hour.
    3. If the system has a door does it have a minimum of two interlocks? Note: A door is used to put a sample into the cabinet. If a part of the shielding is opened for maintenance it is an access panel not a door.
      1. Is at least one of the interlocks designed so that door opening results in physical disconnection of the energy supply circuit to the high-voltage generator? Occasionally a system may have a “shutter” so that when either the shutter or the door is closed energy continues to be supplied to the high-voltage generator and if both were to open simultaneously then the power would be cut.
      2. Is the disconnection dependent upon any moving part other than the door? In most cases the secondary physical disconnect interlock will be visible when the door is open. Relays and magnetic switches contain moving parts and do not meet this requirement.
      3. Will closing the door cause the automatic resumption of x-ray production or is it necessary for an operator to re-initiate x-ray production by taking some action?
    4. Does the system have an access panel?
      1. Do all access panels that allow access to the interior of the cabinet require a tool to open?
      2. Do all access panels have an interlock that prevents production of x-ray when the panel is open?
      3. Will closing an access panel cause the automatic resumption of x-ray production or is it necessary for an operator to re-initiate x-ray production by taking some action?
    5. Has the manufacturer performed a ground fault analysis? Can the product fail via a ground fault in such a way that x-ray production is initiated?
    6. Is there a capture key control? Can the key be removed when in a position that allows the production of x-ray?
    7. Is there a control to initiate and stop x-ray production other than the power key?
    8. Are there at least 2 independent means that indicate when and only when x-ray is being produced? Are they labeled “x-ray on”?
    9. Can an x-ray on indicator be seen from any position that a port, access panel, or door can be operated? Is the indicator labeled “x-ray on”?
    10. Is the system designed to admit humans? Is the system so large that it would be easy for a human to walk into the cabinet?
      1. Is there a control inside the cabinet for terminating x-ray generation?
      2. Can x-ray generation be initiated from within the cabinet?
      3. Are there audible and visible warning signals within the cabinet that are actuated for at least 10 seconds prior to the first x-ray generation after closing any door designed to admit humans?
      4. Visible warning signal within the cabinet that is illuminated when and only when x-rays are being generated?
      5. Signs that indicate the meaning of the warning signals provided to meet the other requirements of this section?
    11. Warning labels
      1. At the location of any controls that can be used to initiate x-rays is there a label that says: Caution: X-Rays Produced When Energized
      2. Is there a label at every port that says: Caution: Do Not Insert Any Part of the Body When System is Energized--X-ray Hazard
    12. Are user instructions provided to purchasers?
      1. Do the instructions include: Potential, current, and duty cycle ratings of the x-ray generation equipment; and adequate instructions concerning any radiological safety procedures and precautions which may be necessary because of unique features of the system?
      2. Do the instructions include a schedule of maintenance necessary to keep the system in compliance with this section?
    13. Does the product require the customer or a third party to be assembled? If so are there adequate assembly instructions provided by the manufacturer?
    14. Is the product used for security screening of items placed on it by members of the public?
      1. Are there means provided to assure that the operator is present at the control area and in a position that permits surveillance of the ports and doors during generation of x-radiation?
      2. Are there means provided to assure that the operator can terminate an exposure?
    15. Is the manufacturer modifying a previously certified system? If so have they re-labeled the system and re-identified and recertified that the modified product meets the requirements of the performance standard?
Field Test Form

The cabinet x-ray field test procedure uses an official form to record the data. This form, FDA 2903 entitled, Cabinet X-Ray Systems Field Test Record can be found at the FDA Forms Catalog (see the FDA intranet home page under Medical Devices).