Field notes from the dark continent of compliance

The DG Inspector Blog

Practical, regulation-accurate guides to shipping dangerous goods. Written by the engineers building DG Inspector — no fluff, no SEO sludge, just the things we wish someone had told us when we started mapping hazmat compliance.

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Compliance · 6 min read

Preparing for a PHMSA Hazmat Compliance Audit

A PHMSA hazmat audit checks systems and records, not just a single shipment — here's what to expect and how to prepare documentation in advance.

Compliance · 5 min read

DG Training Requirements: Who Needs It & How Often

Dangerous goods training is required for anyone who classifies, packs, labels, or ships hazmat — with recurrency every 2 years under IATA, 3 under 49 CFR.

49 CFR · 5 min read

DG Emergency Response Info: What Every Shipment Needs

Every dangerous goods shipment needs a monitored 24-hour emergency response number on the shipping paper — here's what [49 CFR](/blog/49-cfr-hazmat-compliance-checklist-us) §172.604 actually requires.

Fundamentals · 6 min read

How to Choose UN-Certified Packaging for Hazmat

Choosing UN-certified packaging means matching [hazard class](/blog/complete-guide-un-numbers-hazard-classes), packing group, and material compatibility to markings tested against UN performance standards.

Fundamentals · 5 min read

Aerosols as Dangerous Goods: [UN1950](/un/un1950) Shipping Rules

Aerosols ship under UN1950 as Class 2 gases, with subcategories for flammable, corrosive, and non-flammable contents, each carrying different shipping rules.

Fundamentals · 5 min read

Dry Ice Shipping Rules Explained ([UN1845](/un/un1845), Class 9)

Dry ice (UN1845) ships as Class 9 with a 200 kg per-package limit, venting-capable packaging, and full air/vessel regulation — here's what shippers must know.

Fundamentals · 6 min read

Radioactive Materials (Class 7): Shipping Requirements

Class 7 radioactive material shipping is governed by activity thresholds, RADIOACTIVE labeling, transport index limits, and NRC licensing — here's how.

Fundamentals · 6 min read

Flammable Liquids (Class 3): Classification & Rules

Class 3 flammable liquids are classified by flash point, with packing groups, CDL thresholds, and IMDG disclosure rules that shift by boiling point too.

Fundamentals · 6 min read

Corrosive Materials (Class 8): Shipping Rules Guide

Class 8 corrosives require packing-group-matched packaging, black-and-white corrosion labels, and strict [segregation](/tools/segregation-checker) from flammables and oxidizers.

Fundamentals · 6 min read

Excepted vs. Limited Quantities in DG Shipping

Excepted quantities and limited quantities both reduce DG paperwork, but they're different provisions with different size caps, packaging, and labels.

Fundamentals · 6 min read

What Is Dangerous Goods (DG) Shipping Compliance?

DG shipping compliance means correctly classifying, packing, marking, and documenting hazardous materials under IATA, IMDG, and 49 CFR rules.

Software · 8 min read

Best Dangerous Goods Software 2026: An Honest Roundup

The six DG software platforms worth evaluating in 2026, compared honestly by workflow, strengths and pricing transparency.

Lithium Batteries · 14 min read

Lithium Battery Shipping Compliance Guide (UN3480/3481/3090/3091)

The full guide to shipping lithium batteries by air, sea and road. UN numbers, packing instructions, state-of-charge limits, marks, labels and the pitfalls that ground freight.

IATA DGR · 7 min read

IATA DGR 67th Edition: What Changed in 2026

Significant amendments in the 2026 IATA Dangerous Goods Regulations: lithium battery provisions, new entries, packing instruction updates and operator variations.

Fundamentals · 9 min read

The Complete Guide to UN Numbers and Hazard Classes

How the UN numbering system works, what each of the 9 hazard classes covers, and how to find the right entry in the Dangerous Goods List.

IMDG · 7 min read

IMDG Code Quick Reference for Marine Shippers

A practical IMDG Code cheat sheet: segregation table, marine pollutants, container packing certificates and the documents required for sea freight.

49 CFR · 7 min read

49 CFR Hazmat Compliance Checklist for US Carriers

Domestic US hazmat compliance under 49 CFR Parts 171-180: classification, packaging, marking, labeling, placarding, shipping papers and emergency response info.

ADR · 7 min read

ADR European Road Transport: A Beginner's Guide

What ADR is, who needs to comply, the structure of the agreement, transport categories, tunnel codes and the documents every European driver carries.

Documentation · 6 min read

How to Read a Shipper's Declaration for Dangerous Goods

Walk through every block of the IATA Shipper's Declaration form, what each field means, and the most common errors that get shipments rejected.

Compliance · 7 min read

Common Hazmat Shipping Mistakes That Cost $25,000+ in Fines

Misdeclaration, undeclared lithium batteries, wrong packing group, missing emergency contact: the mistakes that trigger five-figure PHMSA penalties.

Product · 6 min read

AI vs Manual DG Inspection: Speed, Cost, Accuracy Compared

How AI-assisted dangerous goods inspection compares to traditional manual review on time, cost, error rate and auditability.

Lithium Batteries · 5 min read

Lithium Battery State-of-Charge Limit Explained (PI 965 Section II)

Why standalone lithium-ion batteries shipped by air must be at 30% state of charge or less, where the rule comes from, and how to comply in practice.

Lithium Batteries · 8 min read

Are Lithium Batteries Dangerous Goods? (Yes — Here's Why)

Lithium batteries are classified as Class 9 dangerous goods under every transport regulation. Here is what that means, the four UN numbers involved, and when the lighter Section II rules apply.

Fundamentals · 7 min read

UN Number Lookup: How to Classify Dangerous Goods Correctly

A step-by-step guide to finding the right UN number and proper shipping name for any dangerous good, the mistakes that cause misdeclarations, and a free UN number lookup tool.

Fundamentals · 8 min read

IATA vs IMDG vs 49 CFR vs ADR: Which Regulation Applies?

The four major dangerous goods regulations compared by mode, geography and structure — IATA DGR for air, IMDG for sea, 49 CFR for the US, ADR for European road — and how to know which one governs your shipment.