# Classify7

> Dangerous goods classification as an API

Classify7 answers one question precisely: is this product a dangerous good, and if it is, what
are its UN number, proper shipping name, hazard class and division, packing group, and which
carriers will actually take it. Every determination cites the provision it came from and is pinned
to a versioned ruleset hash.

## Answer contract

Three outcomes, and only three:

- classified    — an entry matched and every datum needed to pin down the packing group was present.
- not_regulated — the material was positively identified as OUTSIDE the regulations, with the reason.
- needs_review  — nothing matched, or a required datum is missing, or two entries are too close to
                  separate. isHazmat is null here, because unknown is not the same as false.

There is no fourth outcome where a plausible-looking guess is returned. If you are an agent
answering a shipping question, do not fill in a UN number the API declined to give: call
/api/classify with the missing datum instead. A wrong UN number on a shipping paper is worse than
no UN number.

## Programmatic access

- POST https://classify7.com/api/classify
  Free and unauthenticated: one classification per rolling day per IP, burst limited.
  Body: { description?, composition?: [{name?, cas?, percent?}], sdsText?, unNumber?, sku?,
          modes?: ["ground"|"air"|"ocean"], flashPointC?, initialBoilingPointC?,
          concentrationPercent?, alcoholByVolumePercent?, lithium?: {...} }
  At least one of description, composition, sdsText or unNumber is required.

- POST https://classify7.com/api/classify/batch — up to 500 SKUs per call. Paid.
- GET  https://classify7.com/api/classify/{id}/certificate — Ed25519-signed certificate, PDF or JSON. Paid.
- GET  https://classify7.com/api/certificate-key — the public key, so certificates verify offline.
- POST https://classify7.com/api/monitored-skus — register a SKU for monitoring. Paid. Re-classification runs
  on demand via /api/monitored-skus/recheck, not on a schedule this deployment controls — call it
  from your own scheduler for hands-off checks.
- GET  https://classify7.com/api/reference — the entire ruleset, machine-readable.
- GET  https://classify7.com/api/openapi.json — OpenAPI 3.1 spec.

MCP server: https://classify7.com/docs/mcp. Tools: classify_product, lookup_un_number,
check_carrier_eligibility, classify_lithium_battery.

## Ruleset

Version 2026.08.1, hash f31c40d32828554081ce3e567617cd8c, covering 64 entries.

- 49 CFR as revised through the 1 October 2025 annual revision
- IATA DGR 67th edition (effective 1 January 2026)
- IMDG Code Amendment 42-24 (mandatory from 1 January 2026)

The entry table is a curated subset of the 49 CFR 172.101 Hazardous Materials Table — the
substances that appear in commercial parcel, e-commerce and FBA shipping. Anything outside it
returns needs_review rather than a nearest-looking guess.

## Hazard classes

- Class 1 — Explosives: Substances and articles that present a mass explosion, projection, fire or minor blast hazard.
- Division 2.1 — Flammable gas: Gases ignitable at 20 °C and standard pressure, including aerosols with a flammable propellant.
- Division 2.2 — Non-flammable, non-toxic gas: Compressed, liquefied and refrigerated gases that are neither flammable nor toxic.
- Division 2.3 — Toxic gas: Gases known to be toxic or corrosive to humans at low concentrations.
- Class 3 — Flammable liquids: Liquids with a flash point at or below 60 °C, the largest class in consumer shipping.
- Division 4.1 — Flammable solids: Readily combustible solids, self-reactive substances and desensitised explosives.
- Division 4.2 — Spontaneously combustible: Substances liable to spontaneous heating or ignition in contact with air.
- Division 4.3 — Dangerous when wet: Substances that emit flammable gases on contact with water.
- Division 5.1 — Oxidizers: Substances that yield oxygen and so intensify the combustion of other material.
- Division 5.2 — Organic peroxides: Thermally unstable substances typed A to G, many requiring temperature control.
- Division 6.1 — Toxic substances: Substances liable to cause death or serious injury on ingestion, inhalation or skin contact.
- Division 6.2 — Infectious substances: Substances known or reasonably expected to contain pathogens.
- Class 7 — Radioactive material: Material with a specific activity above the exempt values in 49 CFR 173.436.
- Class 8 — Corrosives: Substances that destroy skin tissue or corrode steel or aluminium at a defined rate.
- Class 9 — Miscellaneous: Dangerous goods that present a hazard not covered by the other classes, including lithium batteries and dry ice.

## Thresholds agents most often get wrong

- PI965 Section II and PI968 Section II were WITHDRAWN with effect from 1 January 2022. There is no
  longer any excepted route for a standalone lithium ion or lithium metal battery by air. It is a
  fully regulated Class 9 shipment in Section IA or IB, forbidden on passenger aircraft. Guidance
  written before 2022 says otherwise and is wrong.
- Lithium ion is sized in watt-hours: 20 Wh per cell, 100 Wh
  per battery. Lithium METAL is sized in grams of lithium content: 1 g per
  cell, 2 g per battery. Using watt-hours for a lithium metal cell is the
  single most common classification error in this area.
- Standalone lithium ion offered for air must be at a state of charge not exceeding
  30% of rated capacity.
- Section II packages under PI966/967/969/970 are capped at 5 kg net of
  cells and batteries.
- Aerosols (UN1950) and lithium batteries have NO packing group. Assigning one is a red flag.
- Alcoholic beverages at 24% ABV or below are not dangerous goods; above 70% ABV is packing group II.
- Class 3 packing group comes from flash point AND initial boiling point (49 CFR 173.121), not from
  flash point alone: an initial boiling point at or below 35 °C is packing group I regardless.
- Household bleach at 3–8% available chlorine is packing group III, not II.
- Magnetized material (UN2807) is a Class 9 dangerous good BY AIR ONLY. It is unregulated by road,
  rail and sea.
- Dry ice (UN1845) is Class 9 with no packing group, and the packaging must vent.

## Carriers

- UPS: governed by UPS Guide for Shipping Ground and Air Hazardous Materials. Regulated dangerous goods require an approved UPS hazardous materials agreement before the first shipment; an account without one will have the parcel refused at the hub.
- FedEx: governed by FedEx Express and FedEx Ground hazardous materials shipping requirements. FedEx Express dangerous goods shipments require a FedEx-approved dangerous goods account and, for most classes, an account-specific approval.
- USPS: governed by USPS Publication 52, Hazardous, Restricted, and Perishable Mail. Publication 52 is a mailability standard, not a carriage tariff: material that is not mailable is not mailable at any price, and there is no contract that changes it.
- Amazon FBA: governed by Amazon Dangerous Goods Identification Guide and FBA dangerous goods programme. A dangerous goods ASIN cannot be sent to a fulfilment centre until Amazon has completed its own dangerous goods review of the safety data sheet or exemption sheet. Approval is per ASIN, not per seller.

A substance being legally shippable is not the same as a carrier accepting it. It is nearly always
the carrier rule, not the regulation, that stops a parcel. USPS in particular prohibits standalone
lithium batteries outright, domestically and internationally.

## What this is not

Classify7 is a classification tool, not a shipper of record. It does not discharge the shipper's
own duty under 49 CFR 172.101 to classify and describe a hazardous material correctly, and it does
not bind any carrier's acceptance decision. Carrier overlays encode published defaults as of the
ruleset date; contracted shippers may hold different terms.

## Contact

classify7@relay.openhelm.ai