What this is
What is an x-ray inspection check?
What is an x-ray inspection check?
Routine verification that the x-ray system is detecting to its validated sensitivity, performed with certified test pieces of defined material and size passed through the system in representative product, with the reject function confirmed and the result recorded.
What does x-ray detect that metal detection does not?
X-ray discriminates by density, so it detects glass, stone, bone, dense plastics, rubber and ceramic that metal detection cannot see. It also handles metallised film and foil packaging that defeats metal detection. What it does not reliably detect are low-density materials: most soft plastics, wood, cardboard, hair, paper and insects.
Scope
When is a x-ray inspection check required?
This check verifies detection performance. The radiation safety obligations run alongside it and are frequently held nowhere.
Use this template when
- Routine verification of detection sensitivity with certified test pieces at defined frequency
- Start of run, after any stoppage, at product changeover and at run end
- After maintenance, adjustment or software change to the system
- When a new product is introduced, requiring its own sensitivity validation
- Following a foreign material finding that the system should have detected
Do not use it for
- Sensitivity validation, which establishes the achievable detection level per product and is performed on introduction and change
- The radiation survey and state registration, which are radiation safety obligations rather than food safety ones
- Operator radiation safety training, which is a separate requirement with its own record
- The foreign material report, which records an actual finding and its investigation
- Metal detection verification, which is a different technology with different capabilities and its own record
Compliance mapping
Which BRC 4.10 requirements does this satisfy?
X-ray inspection sits under food safety scheme requirements for detection and under a federal radiation performance standard for the equipment itself.
| Clause | Requirement | Where it lands |
|---|---|---|
| BRCGS Issue 9 cl.4.10 | Foreign body detection equipment: validation, verification with test pieces, failure procedures and records | Test pieces |
| 21 CFR 117.130 | Hazard analysis identifying physical hazards requiring a preventive control | Header |
| 21 CFR 117.145 | Monitoring of preventive controls with records signed and dated | System function |
| 21 CFR 117.150 | Corrective action where a preventive control is not properly implemented | Failure response |
| 21 CFR 1020.40 | Cabinet x-ray performance standard: 0.5 mR per hour at 5 cm, interlocks, indicator lights, warning labels | System function |
| State radiation control | Registration of the equipment by the owner with the state radiation control programme, varying by state | Header |
| SQF Edition 9 cl.11.2 | Foreign matter control including detection equipment and incident response | Failure response |
| 9 CFR 417 | Where detection is a CCP, monitoring, corrective action and verification requirements apply | Test pieces |
What it does not cover
- Sensitivity validation per product, which establishes what is achievable and is performed on introduction and on change.
- Radiation survey and state registration, which are equipment obligations distinct from food safety verification.
- Operator radiation safety training, required separately from food safety training on the same equipment.
- The foreign material report, which handles an actual finding and its source investigation.
- Metal detection verification, which covers a different technology with different blind spots.
How to complete it
How to complete a x-ray inspection check, step by step
The check is short. What makes it meaningful is the test piece regime behind it and knowing what happens to product when it fails.
Test pieces should be certified for material and size, and passed through in product rather than through an empty system. Product effect is substantial in x-ray: density, depth, packaging and product presentation all change what is achievable, and a test through air demonstrates the machine works rather than that the inspection works.
Detection varies across the belt width and with the orientation of the object. Test pieces should be presented at the position and orientation where detection is hardest, typically the belt edges and with the piece oriented to present its smallest cross-section. Testing at the easy position produces reassurance rather than verification.
Everything produced since the last successful check is suspect if a check fails. Frequency is therefore a decision about how much product you are willing to hold, not a compliance minimum. Hourly is common; high-risk lines run more often. Decide the number explicitly rather than inheriting it.
A detection that does not result in the pack leaving the line has not protected anyone. The check should confirm the reject mechanism operated, the pack reached the reject bin, and where fitted that bin-full and air-pressure failsafes are functional. Detection without effective rejection is the failure mode that produces product in the market.
What auditors find
Most common x-ray inspection check findings
X-ray findings divide between detection verification and the radiation obligations that frequently have no owner.
| Finding | Clause | What fixes it |
|---|---|---|
| Test pieces passed through an empty system rather than in product. | BRCGS 4.10 | Test in representative product; product effect materially changes achievable sensitivity. |
| Sensitivity validated for one product and applied to others. | BRCGS 4.10 | Validate per product; density, depth and packaging all change what is detectable. |
| Test pieces presented at the easiest position on the belt. | BRCGS 4.10 | Test at the least favourable position and orientation. |
| Reject function not confirmed as part of the check. | 21 CFR 117.145 | Confirm the pack left the line; detection without rejection protects nobody. |
| No defined hold rule when a check fails. | 21 CFR 117.150 | Define in advance what is held; deciding scope after a failure produces narrow decisions under pressure. |
| Equipment not registered with the state radiation control programme. | State regulation | Registration sits with the owner; check state requirements at installation and on relocation. |
| Interlocks, indicator lights or warning labels defeated or missing. | 21 CFR 1020.40 | These are required safety features; a defeated interlock is a radiation safety failure. |
| Operators trained on food safety use but not on radiation safety. | 21 CFR 1020.40 | Provide radiation safety training as a distinct requirement. |
| X-ray assumed to detect low-density material such as wood or soft plastic. | BRCGS 4.10 | Document detection capability by material; low-density contaminants remain a gap. |
| No verification after maintenance or software change. | BRCGS 4.10 | Reverify after any intervention; settings and calibration can change without notice. |
Case in point
Case in point: the upgrade that narrowed the net
A processor replaced metal detection with x-ray on a packing line, on the reasonable basis that x-ray detects more contaminant types and handles the metallised film they had moved to. Validation was performed with certified test pieces, verification ran hourly, records were complete, and the system performed exactly as specified.
Some months later a customer complaint identified a wood splinter from a pallet in a finished pack. The x-ray had not detected it, correctly by its own specification: wood density sits close to many food matrices, and low-density material is where x-ray is weakest. Metal detection would not have found it either.
The gap was not the equipment. It was that the change from metal detection to x-ray had been treated as an upgrade rather than as a change in detection profile, and nothing in the hazard analysis had been revisited to ask what the new system could and could not see.
The template
The template, field by field
The form exactly as it installs. Every field, option, score and conditional rule is editable, and the links to other templates come with it.
4 sections
- Reference
- QUA-021
- Archetype
- Checklist
- Record ID
- CHK-2026-000
- Scoring
- Pass or fail
- Direction
- High is good
- Singleton
- No
- Basis
- BRC 4.10, FSMA
- Links
- Links Asset; feeds Hold
- Tags
- Quality, Food safety, CCP
- Sections
- 4
- Fields
- 41
- Follow up fields
- 4
- Repeating sections
- 0
- Links out
- 4
Header
16 fieldsCheck ID*
Auto sequence. Format CHK-2026-00000.
The record's own ID. Other templates point at this value.
Status*
Drives who this goes to next.
- Planned2 pts
- In progress2 pts
- Complete3 pts
- Deferred0 pts
- Open0 pts
- Closed3 pts
- Overdue0 pts
Date and Time*
Raised By*
Site*
Site ID*
Format SITE-000.
Links to FDN-001 Site ID
Line*
Shift*
Line Lead
Batch Number*
Numeric key joining to your ERP batch record.
Links to External system reference
Product*
Production Date*
X-Ray Unit*
Asset ID*
Format AST-0000.
Links to FDN-002 Asset ID
Check Point*
Last Passing Check At*
Test pieces
8 fieldsFerrous Result*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Non Ferrous Result*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Stainless Result*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Glass Result*
X-ray detects glass where metal detection cannot. This is the main reason for having it.
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Stone Or Ceramic Result
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Dense Plastic Result
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Bone Detection Where Applicable
Relevant for meat products. Bone fragment detection has its own sensitivity.
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
All Test Pieces Recovered*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
System function
6 fieldsCorrect Product Programme Selected*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Image Quality Acceptable*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Reject Mechanism Operated*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Radiation Safety Interlocks Intact*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Warning Lights Functioning*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Operator Radiation Training Current*
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Failure response
11 fieldsAny Test Failed*
- No3 pts
- Yes0 pts
Product Affected By The Failure*
- No3 pts
- Yes0 pts
Quantity Affected
Hold ID
Raise the hold record, then enter its reference.
Links to QUA-003 Hold ID
Product Location
Where the affected product physically is right now.
Work Order ID
Links to MNT-002 Work Order ID
Case ID
Thread key
Operator*
Signature*
Quality*
Second Signature*
QUA-021 · record IDs look like CHK-2026-000 · Links Asset; feeds Hold
Open in KnowellaRun it with agents
From a document you fill in to a programme that runs itself
The check is a test piece and a signature. What fails is the reject nobody confirmed, and the radiation registration nobody owns.
Holds validated sensitivity per product, drives the test piece regime, and applies the defined hold rule automatically when a check fails.
Registers the system as an asset with its radiation obligations attached, including survey and state registration alongside routine maintenance.
Flags a change of detection technology as a management of change event, so the hazard analysis is revisited rather than assumed to improve.
Covers radiation safety training as a distinct requirement from food safety operation of the same equipment.
This template lives in KnowQuality — quality and food safety. HACCP, nonconformance, traceability, laboratory and customer complaints.
Meet KnowQuality→Glossary
X-Ray Inspection Check definitions and key terms
- Product effect
- The influence of product density, depth, packaging and presentation on achievable detection sensitivity.
- Certified test piece
- A sphere or rod of stated material and diameter, traceable, used to verify detection performance.
- Least favourable position
- The location and orientation where detection is hardest, typically belt edges and smallest cross-section presentation.
- Cabinet x-ray system
- An enclosed x-ray system regulated under 21 CFR 1020.40, with required interlocks, indicators and emission limits.
- Reject confirmation
- Verification that a detected pack physically left the line and reached the reject container.
- Failsafe
- A function stopping the line or diverting product when reject air pressure fails or the reject bin is full.
- Sensitivity validation
- Establishing the smallest reliably detectable object per product, performed on introduction and on change.
- Radiation survey
- Measurement confirming emission remains within the performance standard limit at the equipment's external surfaces.
FAQ
Frequently asked questions about x-ray inspection check
Does x-ray detect everything metal detection does?+
Not identically. X-ray detects by density and finds glass, stone, bone, dense plastic, rubber and ceramic that metal detection cannot see, and it works in metallised packaging that defeats metal detection. Fine low-density metals in some product presentations can be harder for x-ray than for a well-set metal detector, and low-density contaminants generally remain a gap for both.
What does x-ray miss?+
Low-density material: most soft plastics, wood, cardboard, paper, hair, string and insects. Wood is the important case because its density sits close to many food matrices and it caused one of the largest US recalls of 2025 by weight. Where these are credible hazards, the control has to be at source rather than at detection.
Do we need to register the equipment?+
In most US states, yes. An x-ray inspection system is a cabinet x-ray system under 21 CFR 1020.40, and state radiation control programmes generally require the owner to register it. The obligation sits with the site rather than the equipment supplier, and it is frequently discovered during a state inspection rather than at installation.
How often should test pieces be run?+
Frequency is a commercial decision constrained by risk, because everything produced since the last successful check is suspect when a check fails. Hourly is common and higher-risk lines run more often. The useful question is how much product you are prepared to hold, and the interval follows from that answer rather than from a scheme minimum.
Does the check cover the reject mechanism?+
It should. Detection that does not physically remove the pack has protected nobody, and reject failures are a recognised route by which detected product reaches the market. Confirm the pack reached the reject container and that failsafes for air pressure and bin-full conditions are functional.
Is a validated sensitivity transferable between products?+
No. Density, depth, packaging and presentation all affect what is achievable, so each product requires its own validation. Applying one product's sensitivity to another produces a documented figure that the system cannot deliver for the product actually running.
Keep going
Related templates and programmes
Industries this is written for
Programmes this belongs to
Used together in Nonconformance and Complaints
Root Cause Analysis
Finds out why something happened rather than who was involved
Corrective and Preventive Action
The single action record used everywhere
Product Nonconformance Report
Records product that does not meet specification
Process Deviation Report
Records a process that ran outside its set limits, even where the product still passed
Hold and Release Record
Places suspect product on hold and records the decision to release, rework or scrap it
Rework Authorization
Authorises rework on nonconforming product and sets out exactly what will be done
More in Quality Inspections
Incoming Material Inspection
Checks material against specification before it is accepted into stock
First Article Inspection
Checks the first piece from a new setup or changeover against every specified characteristic
In Process Inspection
Checks product at set points during production, against the control plan
Final Product Inspection
Checks finished product before it is released to the customer
Packaging Inspection
Checks packaging integrity, labelling, coding and seal quality
Label Verification Check
Confirms the label on the line matches the product being run, including allergens, weight and date code
Written and reviewed by
Siddarth Singh
Founder & Chief Executive Officer, Knowella
Certified Safety Professional and industrial and systems engineer with more than a decade inside food supply chain, freight and manufacturing operations. This page was written against the current text of the standards it cites, not against secondary summaries of them.
- Certified Safety Professional (CSP), Board of Certified Safety Professionals
- MBA, University of Chicago Booth School of Business
- MS and BS, The Ohio State University, Industrial and Systems Engineering
- Six Sigma Black Belt
Sources and last review. Reviewed 16 August 2026 against:
- 21 CFR 1020.40, cabinet x-ray systems performance standard, FDA
- FDA Compliance Guide for Cabinet X-Ray Systems
- BRCGS Food Safety Issue 9 clause 4.10, foreign body detection and removal
- 21 CFR 117, hazard analysis and risk-based preventive controls, FDA
- USDA FSIS 2025 recall data on foreign material
This page is general guidance, not legal advice. Confirm requirements with your jurisdiction’s regulator.