Permanent magnets, electric motors, loudspeakers, magnetrons, magnetic separators, and assemblies that contain them all share a quiet property: they project a magnetic field beyond their own surface. On a bench, that field is a feature. Loaded into an aircraft, a strong enough field can pull on the compass and direction finding instruments a flight crew relies on. That single concern is why air transport rules treat magnetized material as a regulated dangerous good, and why the rule looks nothing like the rules for a flammable or a corrosive.
What makes magnetized material unusual is that the hazard is purely an aviation problem. There is no fire, no toxicity, no reactivity. There is only the magnetic field and the aircraft’s instruments. As a result, magnetized material is regulated for air but is generally not a dangerous good by road, rail, or sea. Below is what shippers and forwarders need to know to classify it correctly, pack it so it is acceptable, label it, and document it on the air waybill.
What counts as “magnetized material”?
For air transport, magnetized material is defined by a measured field strength rather than by what the item is. A material is treated as magnetized material when, packaged for air transport, it produces a magnetic field strength of 0.159 A/m (about 0.002 gauss) or more at a distance of 2.1 m (7 ft) from any point on the surface of the package. If the field at that distance is below the threshold, or the package produces no significant compass deflection (less than half a degree), the item is not restricted as magnetized material and can move as ordinary cargo.
The key word is packaged. The number that matters is not the raw strength of the magnet but the field that escapes the finished, padded, shielded package. The same magnet can be a regulated dangerous good in one box and unrestricted in another. Items that commonly trip the threshold include:
- Neodymium and alnico permanent magnets, and magnet assemblies
- Electric motors, generators, and alternators
- Loudspeakers and audio drivers
- Magnetrons and certain measuring instruments
- Magnetic separators, chucks, and clamping tools
- Components and subassemblies built around strong magnets
It is a Class 9 hazard, but only in the air
Magnetized material is assigned UN 2807, Class 9 (miscellaneous dangerous goods), and is handled in the air regulations under Packing Instruction 953. Because the hazard is interference with aircraft navigation, the regulation lives in the air framework (the ICAO Technical Instructions and the IATA Dangerous Goods Regulations) and, in the United States, in 49 CFR when material is offered for transport by aircraft.
By other modes the picture changes. Under the IMDG Code, magnetized material is not subject to the Code’s provisions for sea transport, and by highway or rail it is generally not classified as a hazardous material. That is the opposite of most Class 9 entries, which travel as dangerous goods across modes. It is worth stating plainly to anyone preparing a multimodal move: the magnetized material rules attach when the box goes on a plane, and the same box may carry no dangerous goods obligations on the truck that brings it to the airport.
A package’s stray magnetic field can deflect the aircraft’s magnetic compass and disturb direction finding equipment. The regulation is built around keeping that field small enough, and stowed far enough from the instruments, that it cannot mislead the flight crew. That is the entire purpose of the limits, the label, and the loading rules below.
The numbers that decide everything (PI 953)
Two measurement distances do the work: 2.1 m (7 ft) and 4.6 m (15 ft) from any point on the surface of the package. The field is measured with a gaussmeter, or assessed by the compass deflection method, around the fully assembled package. Three outcomes follow.
- Below the floor, not restricted. If the packaged field is less than 0.159 A/m at 7 ft (or there is no significant compass deflection), the shipment is not magnetized material and ships as ordinary cargo.
- Regulated but acceptable, UN 2807. If the field is above that floor yet does not exceed 0.418 A/m (about 0.00525 gauss) at 15 ft (equivalently, no more than two degrees of compass deflection at that distance), the shipment is magnetized material and travels under PI 953 with the handling label, air waybill statement, and prior operator arrangement described below.
- Above the ceiling, shield it down. If the field still exceeds the 15 ft limit, the package is not acceptable as offered. The field must be reduced, through shielding, keeper bars, or repacking, until it is within limits. Carriers routinely refuse magnetized material that exceeds this ceiling.
How magnetized material is prepared under PI 953
Getting a shipment from “too strong” to “acceptable” is a packing problem, and the field falls off quickly with distance. Standard measures include:
- Shielding. Steel-lined boxes or layers of soft iron sheeting redirect and contain the field. The goal is to bring the measured field below the limit at the required distance.
- Keeper bars. Where practical, fitting keeper bars across the poles of permanent magnets closes the magnetic circuit and cuts the stray field.
- Opposing polarities. Devices such as magnetrons and light meters can be packed so the polarities of individual units oppose one another, reducing the combined external field.
- Spacing and cushioning. Non-magnetic cushioning that holds the magnetized article away from the outer wall can reduce the magnetic field measured outside the package and protect the contents in transit. The finished package should still be tested to confirm it is below the applicable limit.
- Prior arrangement with the operator. The shipper must identify the magnetized material to the carrier in advance, so the package is recognized, labeled, and stowed correctly.
The Magnetized Material label
An acceptable magnetized material shipment carries the Magnetized Material handling label. It is a handling mark, not a hazard class diamond: its job is to tell ground crews and loaders to keep the package away from the aircraft’s compass detector unit during loading and flight.
On the aircraft, operators stow magnetized material away from the compass and direction finding equipment. The label is how that requirement travels with the package from the dock to the hold.
Documentation: why no Shipper’s Declaration is required
Most dangerous goods offered for air require a completed Dangerous Goods Declaration (DGD). Magnetized material is one of a short list of entries that does not. Instead of a Declaration, the required information is carried on the air waybill itself:
, Packing Instruction 953, documentation provision
A few practical points follow from this. The UN number is not required for magnetized material in the air waybill statement; the words “magnetized material” and the package count do the job. And waiving the Declaration does not waive everything else: the prior arrangement with the operator, the handling label, and PI 953-compliant packing all still apply. When a shipment also contains other dangerous goods that do require a Declaration, or when you want the documentation handled correctly the first time, DGM New York issues dangerous goods declarations for air, sea, and ground on the shipper’s behalf.
Where magnetized material shipments go wrong
- Assuming “it’s just a magnet.” The threshold is a measured field, not a guess. Strong assemblies frequently exceed it.
- Testing the magnet, not the package. Shielding and packing change the answer. Measure the field that escapes the finished package.
- Skipping the air waybill statement or the operator arrangement. Even with no Declaration required, the “Nature and Quantity of Goods” entry and the prior arrangement are not optional.
- Offering a package that is too strong. Above the 15 ft ceiling it will be refused; shield first, then tender.
- Letting air training lapse. Anyone preparing these shipments needs current air training. Under the IATA cycle, recurrent training runs every 24 months, tighter than the U.S. ground cycle. See how often hazmat training is required, and DGM’s dangerous goods air training.
| UN number | UN 2807 |
|---|---|
| Class | Class 9, Miscellaneous dangerous goods |
| Packing Instruction | PI 953 (passenger and cargo aircraft, and cargo aircraft only) |
| “Not restricted” floor | < 0.159 A/m (0.002 gauss) at 2.1 m / 7 ft, or no significant compass deflection |
| Acceptance ceiling | ≤ 0.418 A/m (0.00525 gauss) at 4.6 m / 15 ft |
| Label | Magnetized Material handling label, “keep away from aircraft compass detector unit” |
| Shipper’s Declaration | Not required if the air waybill shows “magnetized material” and the package count |
| Other modes | Not subject to the IMDG Code (sea); generally not regulated by road or rail |
Shipping magnets, motors, or magnet assemblies by air?
DGM New York classifies magnetized material, helps you measure and shield the packaged field to PI 953, prepares the air waybill statement, and, where other dangerous goods are in the box, issues the Dangerous Goods Declaration. We also run IATA dangerous goods air training and broader hazmat training so your team stays current. Bring us the shipment before it is tendered, and we will catch the compliance issues before they become delays.
Call DGM New York: 908-862-1010
Frequently asked questions
Is magnetized material considered dangerous goods?
For air transport, yes. It is UN 2807, Class 9, when the packaged field reaches the threshold. Below the floor (less than 0.159 A/m at 7 ft, or no significant compass deflection) it is not restricted. By sea it is not subject to the IMDG Code, and by road or rail it is generally not regulated.
What is the UN number for magnetized material?
Magnetized material is UN 2807, Class 9 (miscellaneous dangerous goods), shipped by air under Packing Instruction 953.
Do I need a Shipper’s Declaration for magnetized material?
No. A Shipper’s Declaration for Dangerous Goods is not required as long as the words “magnetized material” and the number of packages appear in the “Nature and Quantity of Goods” box on the air waybill (or the equivalent location on alternate transport documentation). The handling label, PI 953 packing, and prior arrangement with the operator still apply.
What label does magnetized material need?
The Magnetized Material handling label, which instructs handlers to keep the package away from the aircraft compass detector unit. It is a handling mark rather than a hazard class diamond.
How is the magnetic field measured?
With a gaussmeter, or by the compass deflection method, around the fully packaged item at 2.1 m (7 ft) and 4.6 m (15 ft) from any point on the surface. The field at 7 ft sets whether it is restricted; the field at 15 ft sets whether it is acceptable as offered.
Is magnetized material regulated for ocean or ground shipping?
The regulated mode is air. Under the IMDG Code, magnetized material is not subject to the Code for sea transport, and by highway or rail it is generally not classified as a hazardous material. The obligations attach when the package is offered for transport by aircraft.
Disclaimer: This article and any material on this website are for general informational purposes only and do not constitute dangerous goods training, consulting, legal advice, or shipment specific compliance guidance. A qualified subject matter expert must be consulted to evaluate the applicable regulations, including 49 CFR, the ICAO Technical Instructions, the IATA DGR, and the IMDG Code, for any specific shipment, product, operation, or training requirement.