Hazard Class 2: Compressed Gases (2024)

FAQs

What are hazard Class 2 compressed gases? ›

Class 2 hazards are compressed gases, which are divided into four categories: flammable/combustible gases, non-flammable/non-poisonous gases, toxic/poisonous gases, and oxygen. For use as logo or map symbology. A green sign, with “non-flammable gas” displayed in the middle.

The HAZMAT Class 2 in United States law includes all gases which are compressed and stored for transportation. Class 2 has three divisions: Flammable (also called combustible), Non-Flammable/Non-Poisonous, and Poisonous.

Examples for Class 2 dangerous goods are aerosols, compressed gas, fire extinguishers, refrigerant gases, lighters, acetylene, carbon dioxide, helium, hydrogen, oxygen, nitrogen, natural gas, petroleum gases, liquified, butane, propane, methane, ethylene.

Hazard classification

Compressed gases are classified as class I, II, III, or IV in order of decreasing hazard. * Classes are based on the lethal concentration to 50% of test animals (rats) of each gas (LC50). * Note: The California Fire Code uses a different classification system.

(1) The classes of hazardous properties are as follows: (a) class 1—explosiveness: (b) class 2—flammability, gases: (c) class 3—flammability, liquids: (d) class 4—flammability, solids: (e) class 5—capacity to oxidise: Page 7 7 Hazardous Substances (Classification) Notice 2017 July 2017 (f) class 6—toxicity: (g) class 8 ...

By comparison, Class 2 compressed air dryers, with a pressure dew point of -40 °C or better, are typically specified for use in food processing, general manufacturing or industrial processes, where the air quality requirements are less stringent than those required in Class 1.

Subsets of Class 2 are:

2.1 Flammable Gas – Hydrogen Compressed, Ethylene, Butylene, Acetylene, etc. 2.2 Non-Flammable Gas – Oxygen Compressed, Nitrogen Compressed, etc. 2.3 Poisonous Gas – Phosgene, Sulfur Tetrafluoride, Insecticide Gasses, etc.

Common compressed gases are: propane, nitrogen, chlorine, helium, and oxygen.

3) Determine the hazard group

There are two hazard groups for gases and liquids. Group 1: Group 1 designates media as hazardous. Group 1 hazardous media are all media that are either explosive, extremely flammable, highly flammable, flammable, very toxic, toxic, or oxidizing. Group 2: Group 2 covers all other media.

Category 2 describes: chemicals that, based on animal studies, “can be presumed to have the potential to be harmful to human health following single exposure” (UNECE 2013).

What is gas definition for Class 2? ›

Gas is one of the three principle states of matter. The properties of gases are distinctly different from those of liquids and solids—the other principle states. Gases have neither a definite volume nor a definite shape. In contrast, both solids and liquids have a definite volume, and solids have a fixed shape.

Fire and Explosion

Compressed gases may be flammable or accelerate fires or explosions. Oxygen may turn a small fire into an explosion.

The gas cylinder pictogram is a symbol with an image of a black silhouette of a gas cylinder on a white background framed by a red diamond. If you see this pictogram on a chemical label affixed to a container, it means that the chemical is a gas under pressure.

Compressed air, even at relatively low pressures (as low as five psi) can cause serious injuries to the eyes, ears, or any other body part. Compressed air can even enter the bloodstream through a break in the skin or through a body opening and cause air bubbles in the blood that lead to serious medical problems.

Subsets of Class 2 are:

2.1 Flammable Gas – Hydrogen Compressed, Ethylene, Butylene, Acetylene, etc. 2.2 Non-Flammable Gas – Oxygen Compressed, Nitrogen Compressed, etc. 2.3 Poisonous Gas – Phosgene, Sulfur Tetrafluoride, Insecticide Gasses, etc.

b. Class II—Locations in which combustible dusts (either in suspension, intermittently, or periodically) may or may not be in sufficient quantities to produce explosive or ignitable mixtures.

Hazards associated with compressed gases include oxygen displacement, fires, explosions, and toxic gas exposures, as well as the physical hazards associated with high pressure systems. Special storage, use, and handling precautions are necessary in order to control these hazards.

Class II liquids are combustible liquids that have a flash point at or above 100 °F (37.8 °C) and below 140 °F (60 °C). Typical Class II liquids include liquids such as camphor oil, diesel fuel, pine tar, and Stoddard solvent.