Magnetic Cargo: Classification and Air Shipping Rules

Speakers, motors, and instruments can be 'magnetic cargo' - regulated for air because strong fields can affect aircraft instruments.

On this pageWhy magnetism matters in air freight The 0.418 A/m rule Products commonly affected The magnetic test report Packaging and stowage

Why magnetism matters in air freight

A magnetic field strong enough to interfere with aircraft navigation or compass systems is regulated. Airlines measure the field at a set distance to decide if the package is acceptable.

The 0.418 A/m rule

Under IATA, if the magnetic field strength at 2.1 m (7 ft) from any surface of the package exceeds 0.418 A/m (or 4.6 kg for certain references), the package is classified as magnetic dangerous goods and needs a magnetic test report and special stowage (often away from the aircraft's compass area).

Products commonly affected

Loudspeakers and audio equipment with large magnets
Electric motors and generators
MRI and medical imaging components
Some meters, sensors, and scientific instruments
Magnetized steel products and tooling

The magnetic test report

A qualified test measures the field at 2.1 m and 4.6 m and states whether the package meets the limit. If it exceeds the limit, demagnetization, shielding, or re-packaging may be required; otherwise the package may be refused.

Packaging and stowage

Keep magnets grouped to reduce external field where possible
Use steel shielding or distance packing to lower the measured field
Mark the package and provide the test report to the airline
Expect stowage restrictions on passenger aircraft

Even if a product 'works fine', the field measurement decides the rule. Always test before booking magnetic goods by air.

Frequently Asked Questions

Does the 0.418 A/m limit apply to sea freight?

Sea (IMDG) has its own magnetic provisions; the 2.1 m air rule is an IATA standard, but strong magnets are still managed.

My speaker is small - is it still magnetic cargo?

Small speakers may fall under the limit, but only a test confirms it. Do not assume.

What if the test fails?

You can demagnetize, add shielding, or repack to reduce the field, then re-test.