What are you shipping?

Why three regulations matter for every shipment

Hazardous materials shipping in the United States and globally is governed by overlapping regulatory frameworks. A single shipment crossing borders or modes of transport may be subject to all three of the following, simultaneously. Misclassifying a material — or applying the wrong regulation for the mode of transport — can result in civil penalties, criminal liability, or, more importantly, catastrophic incidents that endanger lives and property.

49 CFR — The U.S. Backbone

Title 49 of the Code of Federal Regulations, Subchapter C (Parts 171–180), is administered by the Pipeline and Hazardous Materials Safety Administration (PHMSA). It defines the Hazardous Materials Table (49 CFR §172.101), which assigns proper shipping names, hazard classes, identification numbers (UN/NA), packing groups, and labeling/placarding requirements for every regulated material moving by highway or rail in the United States. Compliance is not optional — shippers, carriers, and consignees all bear distinct responsibilities, and PHMSA enforces civil penalties up to roughly $96,624 per violation per day, with criminal penalties for willful violations.

IATA DGR — The Standard for Air

The IATA Dangerous Goods Regulations are updated annually and incorporate the ICAO Technical Instructions, which carry treaty force under the Chicago Convention. Air shipments carry stricter quantity limits, packaging requirements, and documentation than ground — for good reason. A leak at 35,000 feet has nowhere to vent. Lithium battery shipments in particular have driven significant DGR revisions over the last decade following multiple in-flight incidents.

IMDG Code — Maritime

Adopted by the International Maritime Organization (IMO), the IMDG Code is mandatory under the SOLAS Convention for vessels carrying dangerous goods at sea. It harmonizes with the UN Recommendations on the Transport of Dangerous Goods (the "Orange Book") but adds maritime-specific provisions: stowage and segregation requirements, marine pollutant designations, and limitations on what may be carried on passenger vessels.

The ERG — Your First-Response Bridge

The Emergency Response Guidebook (ERG), updated every four years by PHMSA in cooperation with Transport Canada and Mexico's SICT, is what links the regulatory world to the operational one. When responders arrive at an incident, they do not have time to consult 49 CFR. They look up the UN number on a placard or shipping paper, find the assigned ERG guide number (a three-digit number from 111 to 174 in the 2024 edition), and follow the standardized actions for that guide. This tool surfaces that same ERG guide number from your UN-identified material, so you can attach it to your shipping documents and emergency response plans before anything goes wrong.

UNLookup is a reference utility. It is not a substitute for current editions of 49 CFR, the IATA DGR, the IMDG Code, or the ERG. Always verify against the official source applicable to your mode of transport before tendering a shipment.