The 9 Classes of Hazardous Materials Guide

The 9 Classes of Hazardous Materials Guide

In Brazil, every hazardous product must be classified into one of nine internationally standardized classes before transport. These classes follow the "Orange Book," UN Model Regulations, which was created with the purpose of standardizing hazardous materials transport rules worldwide. Brazil's ANTT Resolution 5.998/22 adopts this international system and establishes how products must be packaged, labeled, documented, and handled during road transport.

Critical Distinction: The hazardous materials classification for transport (also referred to as TDG - Transportation of Dangerous Goods from the UN), is NOT the same as the GHS classification (Global Harmonized System, also from the UN). The systems are different because they have different objectives - TDG uses 9 classes focused on the risk each product presents when transported, such as flammable, corrosive, while GHS is broader, covering health, physical and environmental hazards, with a total of 29 classes and subclasses. GHS is used in Section 2 of Safety Data Sheets (SDS, formerly MSDS). This confusion between the two systems is not just a simple mistake, it is a serious error that can constitute a violation of Brazilian law.

Who Classifies Products in Brazil?

Classification responsibility belongs to:

  • The manufacturer, or
  • The shipper, guided by the manufacturer, or
  • The competent authority, when applicable

Classification is based on the product's physical, chemical, toxicological, and environmental characteristics.

The Classification Decision Process

Evaluate Product Physical, Chemical & Toxicological Characteristics
Is this product DANGEROUS for road transport under Brazilian regulations?
YES
CLASSIFY INTO ONE OF 9 CLASSES
1
Identify Primary Hazard Class (1-9)
2
Check for Subsidiary Risks
3
Determine Packing Group (I, II, III)
4
Check Brazilian List of Dangerous Products
5
Verify Special Provisions
6
Document Complete Classification
7
Prepare Labels & Transport Documents
NO
NOT REGULATED
Required Actions:
  • Document decision
  • Keep records for audit
  • No special labels needed
  • Standard transport applies

QUICK DECISION GUIDE

  • Product is Dangerous: Follow the 7-step classification process
  • Product is NOT Dangerous: Document determination and proceed with standard transport

THE 9 HAZMAT CLASSES

International UN System | Regulated in Brazil by ANTT Resolution 5.998/22
1
EXPLOSIVES
Divided into six divisions (1.1 through 1.6) based on the type and intensity of explosive hazard:
1.1 Mass explosion 1.2 Projection hazard 1.3 Fire hazard 1.4 Minor hazard 1.5 Insensitive 1.6 Extremely insensitive
2
GASES
Divided into three subclasses:
2.1 Flammable 2.2 Non-Flammable 2.3 Toxic
3
FLAMMABLE LIQUIDS
Includes paints, varnishes, thinners, and similar products. Categorized by packing groups (I, II, or III) based on danger level.
4
FLAMMABLE SOLIDS
Divided into three divisions:
4.1 Flammable solids 4.2 Spontaneously combustible 4.3 Dangerous when wet
5
OXIDIZING SUBSTANCES & ORGANIC PEROXIDES
Divided into two divisions:
5.1 Oxidizing Substances 5.2 Organic Peroxides
6
TOXIC & INFECTIOUS SUBSTANCES
Divided into two divisions:
6.1 Toxic Substances 6.2 Infectious Substances
7
RADIOACTIVE MATERIALS
Unique class with specialized labeling and handling requirements. Does not follow standard label formats used for other classes.
8
CORROSIVE SUBSTANCES
Materials that damage tissue or metals. Special labeling rule: text and numbers appear in WHITE (not black) on labels.
9
MISCELLANEOUS DANGEROUS GOODS
Products presenting transport hazards not covered by Classes 1-8. Must display Class 9 label and proper shipping name.

KEY CLASSIFICATION CONCEPTS

Primary Risk The main hazard class of the product
Subsidiary Risk(s) Additional hazards requiring extra labels
UN Number Four-digit identification code for each product
Proper Shipping Name Official transport designation for documentation

PACKING GROUPS (Classes 3, 4, 5, 6, 8)

I
High Danger
II
Medium Danger
III
Low Danger

Understanding Subsidiary Risks

Many dangerous products have more than one type of hazard. These hazards are identified through the Risk Number (top section of the orange panel) and appear on package labels:

  • Primary Risk: The main hazard class (first digit of the risk number)
  • Subsidiary Risk(s): Additional hazards (second and third digits, when present)

How to Read the Orange Risk Panel

Example 1: Product with Subsidiary Risk

X886
1831
1st digit (X): "Dangerous when wet" - product reacts with water
2nd & 3rd digits (88): Highly corrosive (repeated number = greater intensity)
4th digit (6): Toxic/poisonous (subsidiary risk)
UN 1831 = Sulfuric Acid
Primary Class: 8 (Corrosive)
Subsidiary Risk: 6 (Toxic)

Example 2: Highly Flammable Product

33
3475
1st digit (3): Flammable liquid
2nd digit (3): Flammable liquid (repeated = highly flammable)
UN 3475 = Gasoline and Ethanol Mixture
Primary Class: 3 (Flammable Liquid)
Subsidiary Risk: None - repeated number indicates high intensity

Example 3: Product WITHOUT Subsidiary Risk

40
1350
1st digit (4): Flammable solid
2nd digit (0): Zero indicates absence of secondary risk
UN 1350 = Sulfur
Primary Class: 4 (Flammable Solid)
Subsidiary Risk: None
Important Rules About Risk Numbers:
  • When a number is repeated (e.g., 33, 88), it indicates GREATER intensity of the hazard
  • When the number is 0 (e.g., 40), it indicates ABSENCE of secondary risk
  • The letter X at the beginning means the product reacts dangerously with water - DO NOT use water in emergencies!
  • Class labels must be placed close to each other on the packaging when there are subsidiary risks

The Brazilian List of Dangerous Products

Brazil maintains an official list of commonly transported dangerous products with:

  • UN Numbers
  • Proper shipping names
  • Risk classes and subsidiary risks
  • Packing groups
  • Special provisions
  • Limited quantity limits
To check the products list, access:
ABTI Dangerous Products List

GHS, SDS Classification vs. TDG, Transport Classification

What's the Difference?

GHS (Globally Harmonized System) has a broader focus on the chemical product. It evaluates not only hazards during transport, but also other risks related to the use, storage, and safe handling of chemical substances in warehouses, factories, and laboratories. It is the system that guides the preparation of Section 2 of the Safety Data Sheet (SDS, formerly MSDS). Think of it as "what happens inside the factory."

The transport classification, also called TDG (Transportation of Dangerous Goods) is detailed in the Orange Book (UN Model Regulations for the Transport of Dangerous Goods). Its objective is to identify product hazards during movement on highways, railways, airways or waterways. This classification guides emergency responders, carriers, and authorities about the risks that exist during transport. Think of it as "what happens on the road."

Aspect GHS (ABNT NBR 14725) Transport (ANTT 5.998/22)
Purpose Workplace safety - storage & handling Transport safety - movement on roads/rails/air/sea
Focus Worker protection during daily use Public safety & emergency response during transport
Classification basis Health, physical, and environmental hazards Risks during transport (fire, explosion, leakage)
Found in FISPQ/SDS Section 2 (Hazard Identification) FISPQ/SDS Section 14 (Transport Information), transport documents, labels, placards
Number of classes Multiple hazard categories 9 main classes
Used for Day-to-day operations inside facilities Shipping, emergencies, and regulatory compliance

Practical Example: Acetone

Acetone is a common industrial solvent. Here's how it's classified in BOTH systems:

GHS Classification (Workplace/Storage):

  • Flammable Liquid - Category 2
  • Eye Irritation - Category 2A
  • STOT Single Exposure - Category 3 (narcotic effects)

What this means for workers: Wear safety glasses, use in ventilated areas, avoid prolonged exposure, keep away from heat sources.

Transport Classification (Road Transport):

  • UN 1090
  • Proper Shipping Name: ACETONE
  • Class: 3 (Flammable Liquids)
  • Packing Group: II (Medium danger)

What this means for transport: Must use approved packaging, display Class 3 labels, carry emergency response information, follow specific routing restrictions.

Why the Same Product Has Different Classifications

The systems evaluate different risks:

  • GHS looks at what happens when workers handle the product daily - chronic exposure, skin contact, inhalation over time
  • Transport looks at what happens in an accident - immediate fire risk, explosion potential, environmental damage from a spill

Example: A product might be highly toxic if inhaled daily (important for GHS) but stable during transport (less critical for transport classification). Conversely, a product might be safe for daily use but extremely flammable during transport.

Critical Rule: NEVER use only the GHS classification from your FISPQ/SDS for transport purposes. You must perform a separate transport classification according to ANTT regulations. Both are legally required, and both serve different purposes.

Where to Find Each Classification

  • GHS Classification: Section 2 of the FISPQ/SDS (Hazard Identification)
  • Transport Classification: Section 14 of the FISPQ/SDS (Transport Information) - but always verify independently

For more information specifically about GHS, access: https://pubchem.ncbi.nlm.nih.gov/ghs/

Classification Steps for Brazil

1
Evaluate the product's physical, chemical, and toxicological properties
2
Determine if it's dangerous for transport under Brazilian regulations
3
If dangerous, identify the primary hazard class (1-9)
4
Check for subsidiary risks
5
Consult the official Brazilian List of Dangerous Products
6
Determine packing group (if applicable)
7
Document everything for transport documents and labels

Special Cases in Brazil

Empty and Uncleaned Packaging

Except for Class 7 (radioactive), empty packaging that contained dangerous products must be classified and labeled according to what they last contained.

Format: UN 3509 EMPTY PACKAGINGS, UNCLEANED, 9

Limited Quantities

When transporting small quantities that meet limited quantity limits, certain requirements may be exempted. The document must include the notation "QUANT. LTDA".

Waste Products

Add "WASTE" before the shipping name:

Example: UN 1824 WASTE SODIUM HYDROXIDE SOLUTION 8 II

Why Accurate Classification Matters

For Emergency Response First responders need correct hazard information immediately
For Compatibility Prevents dangerous reactions between incompatible materials
For Legal Compliance Protects against criminal prosecution under Brazil's Environmental Crimes Law
For Safety Ensures proper precautions throughout the transport chain
Consequences of Incorrect Classification:
  • Personal injuries or environmental damage
  • Criminal liability under Article 56 of Environmental Crimes Law
  • Immediate fines and cargo detention
  • Business license suspension
  • Reputational damage

Required Documentation in Brazil

Classification information must appear in:

Transport Document Complete with UN number, proper shipping name, class, and packing group
FISPQ/FDS (ABNT NBR 14725) Section 14 contains transport information
Emergency Information Sheet (ABNT NBR 7503) No longer mandatory, but still recommended for safety and quick reference
Labels and Placards Visual identification on packages and vehicles

Quick Reference Guide

MANDATORY LEGAL REQUIREMENTS

  • Brazil requires transport classification, not just GHS
  • Classification must be done before transport
  • Both shippers and carriers are responsible for errors
  • Documentation must be in Portuguese
  • Criminal penalties apply for violations

OPERATIONAL BEST PRACTICES

  • Review classifications regularly as regulations update
  • Train all personnel on classification requirements
  • Maintain documentation for audit purposes
  • Verify classifications provided by suppliers
  • Consult experts when uncertain

Common Classification Errors

  • Using only GHS classification
  • Assuming foreign classifications apply in Brazil
  • Omitting subsidiary risks
  • Wrong packing group designation
  • Incomplete product descriptions
  • Not classifying empty containers
  • Failing to update after formulation changes

Conclusion

The international 9-class dangerous products system, adopted by Brazil through ANTT regulations, ensures consistent hazard communication throughout the transport chain. Despite the complexity of regulations for handling and transporting hazardous materials, companies can achieve compliance quickly with robust processes and proper checks, operating safely and in full compliance.

KEY TAKEAWAYS

  • Classification is mandatory before transport in Brazil
  • Transport classification differs from GHS classification
  • Both shippers and carriers are legally responsible
  • Incorrect classification can result in criminal charges
  • When in doubt, consult qualified experts. Hazmat Line can recommend the most suitable professional for your case.

Invest in proper classification and solid processes—your company can achieve full compliance safely and efficiently.

Need Help with Hazardous Materials Transportation Compliance? Contact Hazmat Line. Click Here

This article provides educational information about dangerous products classification in Brazil. It does not constitute legal advice and does not replace official regulations. For specific classification questions, consult qualified Brazilian regulatory experts.
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