Class 2 dangerous goods: gases and their transport

Transporting Class 2 dangerous goods requires rigor, training, and strict compliance with transportation regulations. These materials include various gases, whether flammable, toxic, or simply compressed. After reviewing Class 1 dangerous goods together, let’s now explore everything you need to know about Class 2 hazardous materials.

What is a Class 2 dangerous good?

Class 2 includes gases in different forms: compressed, liquefied, or dissolved under pressure. These hazardous materials require controlled handling since their mere release can pose risks of explosion, fire, or poisoning. Unlike flammable liquids from Class 3 or corrosive materials from Class 8, gases have invisible physical properties, making them more complex to manage.

At Enviro Urgence, we assist companies that need to transport these materials in full regulatory compliance. If you regularly handle pressurized containers, we can help you secure your operations.

The subclasses of Class 2

The Transportation of Dangerous Goods Regulations (TDGR) define three main subcategories. Each has a specific primary class.

Class 2.1 – flammable gases

Subclass 2.1 covers flammable gases. Propane, butane, and acetylene are among them. These materials are widely used in industry but present a high risk of explosion when improperly stored. Transporting this type of hazardous material requires certified containers and clear labelling.

Class 2.2 – non-flammable and non-toxic gases

This subclass includes non-flammable, non-toxic gases such as nitrogen or carbon dioxide. Although they are not combustible, these gases can cause asphyxiation in confined spaces. As with other materials, proper classification remains essential to avoid incidents.

Class 2.3 – toxic gases

Subclass 2.3 includes toxic gases such as chlorine or ammonia. These materials are extremely dangerous and can cause severe poisoning. Handling them requires specialized protective equipment and strict protocols.

How to identify a Class 2 material

A Class 2 dangerous goods can be identified by several mandatory elements defined in the TDGR. Identification is based on official classification and standardized labels. Here are the main points to check:

• UN number: each material has a unique code (for example, UN 1978 for propane).
• Pictogram: gases are identified by a diamond-shaped label. Red for Class 2.1 (flammable gases), green for Class 2.2 (non-flammable, non-toxic gases), and white with a skull for Class 2.3 (toxic gases).
• Primary class mention: always indicated on the shipping document and containers.
• Shipping documents: confirm classification, risks, and applicable safety measures.

Which products fall under this class of hazardous materials?

Class 2.1

• Propane
• Butane
• Isobutane
• Acetylene
• Ethylene
• Methane
• Hydrogen
• Compressed natural gas (CNG)
• Liquefied petroleum gas (LPG)

Class 2.2

• Nitrogen
• Carbon dioxide (CO₂)
• Helium
• Argon
• Neon
• Krypton
• Xenon
• Oxygen (oxidizing but classified as 2.2)
• Compressed steam (rare)

Class 2.3

• Anhydrous ammonia
• Chlorine
• Phosgene
• Sulfur dioxide (SO₂)
• Fluorine
• Methyl bromide
• Hydrogen chloride (HCl gas)
• Ethylene oxide

Risks and dangers

Class 2 dangerous goods pose various risks depending on their subclass. Flammable gases can explode if exposed to a spark, while toxic gases can cause severe poisoning even at low concentrations. Non-flammable, non-toxic gases, although seemingly harmless, can lead to asphyxiation when they displace oxygen in enclosed spaces.

Every product, whether propane, ammonia, or nitrogen, requires special attention and proper training to prevent accidents.

Laws and regulations

In Canada, the Transportation of Dangerous Goods Regulations (TDGR) strictly govern the handling and movement of dangerous goods. These regulations require certified containers, standardized labeling, and complete documentation for each shipment. Failure to comply can result in heavy fines and criminal penalties. In Quebec, inspectors ensure compliance with these rules to guarantee the safety of both the public and workers.

Transport and storage

Transporting and storing Class 2 dangerous goods requires rigorous logistics. Gases must be kept in certified containers, protected from heat, and properly ventilated. During transportation, vehicles must display the appropriate hazard labels, and drivers must undergo specific training. Constant monitoring helps prevent leaks, explosions, and poisoning, ensuring the safe delivery of these sensitive products. Below is a table of requirements for the transport and storage of Class 2 gases:

Enviro Urgence, your trusted partner for transporting Class 2 hazardous materials

At Enviro Urgence, we understand the importance of complying with every transportation regulation for hazardous materials. Whether flammable, non-flammable, or toxic gases, we provide reliable and secure service. Our team assists you with classification, packaging, transportation, and storage of your products to reduce risks and remain compliant with Canadian standards. Trust our expertise to protect your employees, your clients, and your operations. Contact us today to discuss your specific needs.