This article focuses on 20-foot and 40-foot general-purpose dry containers used for export and multimodal transport. The principles on structure, cleanliness, weatherproofing, doors, floors and safety marks also apply to other cargo transport units.

Reefer, tank, open-top, flat-rack, flexitank, dangerous-goods, food, pharmaceutical and high-hygiene cargoes require additional checks, such as reefer PTI, tank inspection data, tarpaulin and header checks, load-bearing verification and cargo-specific cleaning.

KEY TERMS

Term	Operational meaning	Control role
CTU – Cargo Transport Unit	A freight container, swap body, vehicle, rail wagon or similar unit used in multimodal transport.	The unit whose fitness must be established before packing.
Container condition check	Inspection of structure, weatherproofing, cleanliness, floor, doors, securing points, labels and safety marks.	Determines whether the container is fit for purpose for the cargo and route.
EIR – Equipment Interchange Receipt	Depot/terminal handover record showing equipment identity, time and visible damage remarks.	Important evidence, but not a complete cargo-specific acceptance check.
CSC Safety Approval Plate	Safety plate under the CSC showing data such as maximum gross mass and allowable stacking mass.	Shows safety approval status and operating limits; it does not replace a physical condition inspection.
ACEP	Approved Continuous Examination Programme mark near the CSC plate.	One of the two post-approval examination arrangements: a dated periodic examination or an approved ACEP.
Weather-tight	Ability to prevent weather ingress under normal transport conditions.	Directly affects wet damage, mould, corrosion and package strength.
Light test	Observation of light entering a closed container to identify possible holes or leaks.	An indicator only; it does not replace an approved leak test when required.
Cargo-worthy	Operational term for a container suitable for a defined cargo.	Cargo-specific: a unit acceptable for steel may be unacceptable for food or odour-sensitive goods.

HOW THE RISK MECHANISM WORKS

1. The CTU operator and the packer have different responsibilities

The CTU Code assigns the CTU operator responsibility for supplying a unit that is fit for purpose, structurally safe and clean, without cargo residues, noxious material, plants, plant products or visible pests. The shipper should request equipment suitable for the cargo and journey. The packer nevertheless remains responsible for checking the unit before packing, controlling floor loading and load distribution, and confirming that it is suitable for the intended cargo.

2. A structurally usable container may still be cargo-incompatible

A unit with no major distortion can still have a pinhole, leaking gasket, chemical odour, oily floor, moisture or weak tie-down points. These may be acceptable for some rough commodities but not for paper, textiles, cosmetics, food, corrosion-sensitive machinery or high-value cargo.

3. Once packed, an equipment defect becomes a cargo-loss mechanism

Roof or door leakage damages cartons and pallets; weak floors can fail under concentrated loads; nails tear packaging; residues cause cross-contamination; defective locking gear compromises sealing; and failed lashing points invalidate the securing plan.

4. Missing pre-loading evidence weakens recovery and cost allocation

If a defect is discovered only after stuffing, the depot or carrier may question whether it pre-existed or was caused by packing operations. Time-stamped photographs, a light-test video, EIR remarks and a written replacement request help separate equipment condition from packing damage.

5. A valid CSC plate does not prove cargo suitability

The CSC plate and a valid periodic-examination date or ACEP mark indicate safety approval and the examination regime. They do not by themselves prove that the container is dry, odour-free, weather-tight, uncontaminated or suitable for a particular commodity.

Equipment release→Depot check→Warehouse recheck→Record/reject if needed→Pack and secure→Close and seal

Control point: do not place the first package into the container until the inspection is complete, evidence is retained and an authorized person has accepted the unit or requested replacement.

RISK ANALYSIS

Unchecked item	Hidden defect	Cargo/schedule impact	Cost or dispute	Control
Frame, corner posts, rails and roof	Distortion, cracks or poor repairs.	Unsafe handling/stacking, rejection or leakage.	Replacement, restuffing, missed cut-off and survey disputes.	Inspect all sides, corner fittings, patches and rust streaks; view the roof only from a safe position or suitable equipment, and do not climb onto it without controlled work-at-height measures.
CSC plate and examination status	Missing plate, an overdue next-examination date, or an ACEP status that cannot be verified.	Stop packing and require the CTU operator to verify, remedy or replace the unit; control action may occur during transport.	Truck/depot delay and rebooking.	Photograph the plate, maximum gross mass and date/ACEP mark.
Doors, locking bars and gaskets	Jammed doors, weak sealing or damaged gaskets.	Water/dust ingress, insecure seal or difficult opening.	Wet damage, security concern and repair charges.	Operate both doors and check hinges, locking gear and seals.
Roof/walls and light test	Pinholes, cracked patches or leakage points.	Wet cartons, mould, corrosion and package collapse.	Complex causation between external water and internal moisture.	Use the light test and additional approved testing for highly sensitive cargo.
Floor	Rot, breaks, moisture, oil/chemical stains or protrusions.	Floor failure, torn packaging, slip risk and contamination.	Cargo damage, safety liability and cleaning/repair cost.	Inspect the full floor under safe conditions; do not touch or deliberately smell unknown residue. Isolate, photograph and request assessment by the CTU operator or a competent cleaner; transfer testing should only be done under an approved procedure with suitable PPE.
Odour and residues	Persistent chemical, seafood or agricultural odours.	Cross-contamination and buyer rejection.	Reconditioning, disposal or insurance dispute.	Open the doors in a well-ventilated area and assess from outside without deliberate deep inhalation. If chemicals, fumigants or a hazardous atmosphere are suspected, prohibit entry until competent gas testing confirms safety.
Pests, soil and plant debris	Contamination in rails, fork pockets or corners.	Quarantine hold, treatment or re-export.	Cleaning, fumigation and delivery delay.	Inspect internal and external contamination hotspots.
Securing points	Bent, corroded, loose or missing rings/cleats.	Cargo shift, overturning and dangerous door load.	Major cargo loss and weak securing evidence.	Verify condition and do not assume a safe working load. For heavy cargo, use strength data from the operator/manufacturer or an engineered securing plan.
Old placards and marks	Previous DG placards or labels remain.	Incorrect hazardous-cargo handling or terminal rejection.	Gate delay and cleaning/replacement.	Remove obsolete cargo marks but never permanent equipment marks.
Container type	Wrong size/type or unsuitable payload/fittings.	Temperature, volume, floor-load or securing failure.	Equipment change, booking amendment and waiting time.	Match size/type with booking, packing plan and commodity needs.

DOCUMENTS AND DATA TO CHECK

Document/data	Issuer/preparer	Use stage	Fields to match
Booking / equipment release	Carrier, agent or forwarder	Before empty pickup.	Size/type, depot, quantity, commodity restrictions and cut-off.
Gate-out EIR	Depot/terminal	At empty handover.	Container number, time, truck/driver, damage remarks and cleanliness.
CSC plate/examination mark	Affixed to container	Exterior inspection.	Maximum gross mass, stacking mass and date/ACEP.
Inspection checklist	Warehouse/shipper/packer	Before the first package enters.	Exterior, interior, floor, doors, gaskets, light test, odour, pests and lashing points.
Condition photos/video	Driver, warehouse or QA	Before packing and when defects are found.	All sides, number, CSC, floor, roof/walls, doors and close-ups.
Replacement request/record	Shipper, forwarder, carrier and depot	When a unit fails inspection.	Defect, evidence, old/new unit and cost authorization.
Packing plan/cargo data	Shipper/packer	Cargo-specific fitness assessment.	Piece weight, total payload, COG, moisture sensitivity, load distribution and securing.
Reefer PTI record	Carrier/reefer operator	Before refrigerated loading.	Machinery, set point, ventilation, alarms, cable, floor and drains.
Seal record and final photos	Warehouse/shipper	After packing.	Container, seal, doors locked, date/time and witness.

PRE-PACKING INSPECTION PROCESS

Match the equipment release: confirm size/type, container number, depot, booking and intended commodity.
Check the CSC plate: photograph it and verify maximum gross mass and either a valid next-examination date or ACEP mark. If missing or unverified, stop packing and require operator confirmation or replacement.
Inspect the exterior: frame, corner posts/fittings, rails, walls, repairs, cracks, distortion and rust streaks; view the roof only from a safe position/equipment and do not climb without work-at-height controls.
Operate the doors: open and close both panels; check hinges, locking bars, cams/keepers, gaskets and seal point.
Control the atmosphere before entry: open the doors in a well-ventilated area and stand clear of the escaping air. If there is a fumigation sign, taped vents, abnormal odour, or suspected chemical/asphyxiant atmosphere, do not enter until competent testing confirms safety.
Inspect the interior: only after the atmosphere is confirmed safe; check the floor, walls, roof, projections, holes, moisture, liquid, residual odour, debris, old securing material and labels.
Perform a light test: close the unit and look for light ingress. It is only an indicative check; for highly moisture-sensitive cargo, use an additional test approved by the CTU operator or a competent provider.
Check cleanliness and pests: include bottom rails, fork pockets, twist-lock areas, underside and hidden corners.
Confirm cargo compatibility: floor loading, payload, odour, dryness, securing points, ventilation and temperature needs.
Record and decide: accept, conditionally accept or reject. Obtain written repair/replacement approval before packing.

COMMON ERRORS

Error	Cause	Impact	Control
Depot-only inspection	Time pressure or overreliance on the EIR.	Defects or contamination may be missed or arise en route to the warehouse.	Use two checks: gate-out and immediately before packing.
Photos do not show the container number	Only close-up defect images were taken.	Evidence cannot be tied to the correct unit.	Take a wide identity image, then detailed defect images.
No EIR remark	The driver rushed or the depot refused to note it.	Dispute over pre-existing versus shipper-caused damage.	Send time-stamped email/photos immediately if the EIR cannot be amended.
Light test used as the only proof	No light was assumed to mean watertight.	Door or gasket leaks may still occur under transport stress.	Combine with gasket, repair and rust-streak inspection and suitable leak testing.
Odour masking instead of replacement	Attempt to avoid an equipment change.	Persistent contamination and possible chemical impact.	Replace or use an approved cleaning method.
Dirty floor accepted because cargo is palletized	Pallets were assumed to isolate the cargo.	Vapours, liquids and slip risk remain.	Require a clean, dry floor; use barriers only after technical assessment.
Unauthorized repair at the warehouse	Operational pressure.	Changed liability and possible repair charges.	Repair only with written operator/carrier authorization.
Packing first, replacement later	Fear of missing production timing.	Restuffing, additional damage and missed cut-off.	Give QA/warehouse staff stop-work authority.
No written equipment-change record	Telephone-only coordination.	Weak allocation of waiting, handling and restuffing costs.	Confirm in traceable email/chat linked to the booking.

LEGAL AND TECHNICAL SOURCES

Sources reviewed on 21 July 2026. The 2014 CTU Code issued as MSC.1/Circ.1497 remains the official version published by IMO. UNECE’s “2025 revision” is a working document for the WP.24 session scheduled for October 2026 and was not a final replacement at the update date. The CTU Code is non-mandatory in itself; contracts, carrier procedures, national rules and insurance conditions may impose additional requirements.

Source	Role	Application note
IMO/ILO/UNECE CTU Code	Responsibility and safe practice framework for selecting, checking, packing, securing and unpacking CTUs.	The 2014 Code was issued through MSC.1/Circ.1497 and is non-mandatory by itself.
MSC.1/Circ.1497 – CTU Code full text	Chapter 4 assigns responsibilities; chapter 8 covers approval plates, exterior/interior checks and cleanliness.	Primary technical source for the checklist.
MSC.1/Circ.1498 – Informative Material	Provides practical background supporting the CTU Code.	It does not form part of the CTU Code.
International Convention for Safe Containers – CSC 1972	International framework for safety approval, examination and maintenance of containers.	The owner is responsible for subsequent maintenance and periodic examination.
IMO – Safe transport of containers	Explains the roles of SOLAS, CSC, IMDG Code and CTU Code.	Use to identify each instrument’s scope; consult the detailed text for application.
UNECE – CTU Code 2025 revision (working document)	Shows the ongoing revision and restructuring process under WP.24.	A working document for the October 2026 session, not a final replacement as at 21 July 2026.

Translation note: English summaries are for operational reference and do not replace the official source texts.

FAQ

1. If the depot says the container is cargo-worthy, must the warehouse inspect it again?

Yes. Cargo-worthy is a general operational assessment; the packer must still confirm suitability for the specific commodity, moisture/odour sensitivity, load and securing plan.

2. Does a clean EIR mean the container has no defects?

No. An EIR reflects what was recorded at interchange. Pinholes, odour, moisture, gasket defects or weak securing points may require a closer warehouse check.

3. Is a light test enough to prove watertightness?

No. A light test only identifies visible light-entry points. Gaskets, repairs and rust streaks must also be checked, and any extra test for water-sensitive cargo should be approved by the CTU operator or a competent provider.

4. Can a container with a valid CSC plate still be rejected for a dirty floor?

Yes. CSC approval addresses safety, not cargo cleanliness. Transferable stains, liquids or odours may make the unit unsuitable.

5. Who pays for a container replacement?

It depends on cause, timing, EIR, contract and carrier/depot policy. Pre-loading evidence is critical to cost allocation.

6. Can the shipper patch a hole or replace a gasket at the warehouse?

Not without approval. Unauthorized repairs may create liability and safety issues; obtain written CTU-operator/carrier instructions.

7. Does a checklist replace photographs and video?

No. The checklist records the decision; images prove identity, timing and observed condition. Keep both with the EIR and correspondence.

APPLICATION NOTE: Acceptance depends on equipment type, commodity, route, moisture/odour sensitivity, loading, carrier requirements and contract. If structure, fumigants/hazardous atmosphere, chemical residue or load capacity is in doubt, stop packing; do not enter the unit and consult the CTU operator, a competent gas tester or a surveyor as appropriate.

ELECTRICAL – ELECTRONICS – IT EQUIPMENT

F&B

MACHINERY

HOUSEHOLD GOODS

COSMETICS – PERSONAL CARE

ELECTRICAL – ELECTRONICS – IT EQUIPMENT

F&B – FOOD & BEVERAGE

MACHINERY

HOUSEHOLD GOODS

COSMETICS – PERSONAL CARE

QUICK SUMMARY

SCOPE