iata-dangerous-goods 0.2.3

A small, manually verified dangerous-goods shipment validator

IATA dangerous-goods validator

A deliberately small Python validator for a shipper who handles a known set of dangerous goods. It checks package and inner-receptacle quantities, approved packaging configurations, aircraft limitations, and whether the selected rule requires a Shipper's Declaration.

[!IMPORTANT] This project is decision support, not a replacement for the current IATA DGR, its addenda, applicable national rules, operator variations, or trained-person review.

Installation

iata-dangerous-goods requires Python 3.11 or later and has no runtime dependencies.

python -m pip install iata-dangerous-goods

The PyPI distribution is named iata-dangerous-goods; the Python import package is named dg:

from dg import Shipment, validate_shipment

Design

• dg/models.py contains facts about a proposed shipment.
• dg/regulations.py defines versioned regulatory records and transport rules.
• dg/packagings.py catalogs the physical packaging configurations in use.
• dg/un_numbers.py is the manually verified registry for the supported UN numbers.
• dg/validation.py evaluates eligible modes and returns an explainable report.
• dg/declarations.py builds structured declaration fields only after a shipment passes validation.

Regulatory data is rejected outside its encoded effective dates. Forbidden transport is represented explicitly rather than as a zero quantity.

Shipment does not require the caller to choose an aircraft category. After validation, ValidationReport.aircraft_limitation is derived from the selected transport rule and is used automatically when declaration data is generated.

Add a UN number

Transcribe each definition from an authorized copy of the current IATA DGR and check the List of Dangerous Goods entry, every referenced packing instruction, special provisions, current addenda, and relevant operator/state variations. Then create a DangerousGoodsDefinition in dg/un_numbers.py and register it.

When one UN number has multiple proper shipping names, give each definition a stable variant and register both. UN3481 is represented by separate packed_with_equipment (PI 966) and contained_in_equipment (PI 967) definitions. A shipment selects the applicable entry:

Shipment(
    un_number=3481,
    definition_variant="contained_in_equipment",
    lithium_ion_batteries=(
        LithiumIonBattery(watt_hour_rating=Decimal("95"), quantity=2),
    ),
    # ...
)

TransportRule.packing_instruction_section distinguishes Section I, IA, IB, and II rules. Sectioned definitions must encode separate rules for their different quantity, packaging, aircraft, and declaration requirements. For UN3481, set section_determination to SectionDeterminationMethod.LITHIUM_ION_BATTERY_WATT_HOURS. Every battery at or below 100 Wh then selects Section II; any battery above 100 Wh selects Section I. This simplified application accepts batteries only, not individual cells. Battery reports also warn that the indicated battery level must be below 25%; that warning does not collect or verify the actual level.

Packaging is represented by stable application-owned codes. Each code should describe one exact configuration you actually use; for example, outer package, inner receptacles, closures, absorbent material, and performance standard.

The starter catalog contains:

• Plastic bottle in a 4G UN specification box with vermiculite
• Laptop or equipment in a hard-shell Pelican-style case with foam
• Bottle or cartridge wrapped in absorbent mat inside a plastic bag

Cataloging a configuration does not approve it for dangerous-goods transport. After checking the applicable packing instruction, reference the catalog entry from the corresponding rule:

from .packagings import PLASTIC_BOTTLE_IN_4G_BOX_WITH_VERMICULITE

TransportRule(
    # ...
    permitted_packagings=(
        PLASTIC_BOTTLE_IN_4G_BOX_WITH_VERMICULITE,
    ),
)

Shipment packages also use the catalog object directly:

Package(
    packaging=PLASTIC_BOTTLE_IN_4G_BOX_WITH_VERMICULITE,
    # ...
)

Package.packaging_code remains available when a stable string identifier is needed for JSON, forms, or database storage.

Each starter entry has verified_against_dgr=False. Set that flag and add its packing-instruction source references only after checking the exact physical configuration against the current DGR.

PackagingDefinition.dgd_packaging_description stores the controlled package type wording required in the declaration's Quantity and Type of Packing field. For example, the 4G box configurations use Fibreboard Box, producing output such as 1 Fibreboard Box, 4 L. Friendly display names and free-text packaging instructions are never substituted into this DGD field. Declaration generation stops if the selected packaging has no verified DGD wording.

For a generic or N.O.S. entry that requires a technical name, set technical_name_required=True on its DangerousGoodsDefinition. Supply the shipment-specific value when creating the shipment:

Shipment(
    # ...
    technical_names=("chemical A", "chemical B"),
)

The declaration builder renders these immediately after the base proper shipping name as PROPER SHIPPING NAME (chemical A, chemical B).

Run the tests

Install an editable development copy with the packaging tools:

python -m pip install -e ".[dev]"

python -m unittest discover -v

Build the same wheel and source archive that are published to PyPI:

python -m build
python -m twine check dist/*

See the release guide for the Trusted Publishing release process.

The test UN9999 entry is fictional and exists only inside the test suite.