Security Seal
A security seal is a tamper-evident, single-use device used to secure cargo, containers, doors, bags, or other assets so any unauthorized opening or interference leaves visible evidence. In inventory and supply chain operations, seals are applied to outbound trailers, warehouse cages, totes, drums, evidence bags, and high-value bins to prove chain-of-custody, deter pilferage, and support traceability through serial numbers, barcodes, or RFID.
On a manufacturing shop floor, a security seal is recorded against a shipment ID, container ID, lot number, or work order before dispatch. Receiving teams then verify the seal number, condition, and any mismatch against the shipping record to detect theft, substitution, or contamination before materials are released to production. Because seals are designed to be broken or destroyed on removal, their function is evidentiary: a broken seal is a tamper indicator that should trigger quarantine, count verification, and discrepancy reconciliation. In logistics, seal verification sits inside receiving inspection and chain-of-custody control, especially for regulated, high-value, or tamper-sensitive goods. High-security variants—pull seals, cable seals, bolt seals, or heavy plastic seals—offer published break strengths matched to the risk level of the load. Modern seals with sequential numbering, QR codes, or RFID tie the physical device to digital inventory records, improving auditability across transport, warehousing, and final delivery.
- Seal number mismatch at receiving: The trailer arrives with a different seal number than the ASN/BOL record, forcing a hold and manual investigation. This usually points to load substitution, a documentation error, or an unrecorded intermediate opening.
- Wrong seal strength for the application: Using a light-duty plastic seal on a high-risk door or container can allow removal without obvious damage, defeating tamper evidence and increasing shrinkage risk.
- Poor seal governance in inventory systems: Without scanning seal IDs into the WMS/ERP against the pallet, tote, or container record, the warehouse loses traceability. This makes it impossible to prove custody or isolate the affected lot after a discrepancy.
Is a security seal a security control or a tracking control?
Both. Mechanically it is a tamper-evidence control; operationally it becomes a tracking control when the seal ID is linked to shipment, lot, or asset master data in the WMS/ERP.
What data should be captured at application time?
Seal type, unique seal number, container ID, material lot, timestamp, operator ID, and departure point; in higher-control environments, add photos and GPS/trailer metadata.
What is the operational meaning of a broken seal?
It is not proof of theft by itself, but it is a tamper indicator that should trigger quarantine, count verification, and discrepancy reconciliation before material is accepted into stock.