Dangerous Goods Class 2

A flammable gas is any gas or gas mixture that is sufficiently flammable that it can be ignited when mixed with air in a proportion within a flammable range for that substance at 20°C and at a pressure of 101.3 kPa absolute pressure

What is a Liquified gas

A gas which, when packaged under pressure for transport, is partially liquid at a temperature above –

What is a Permanent gas

• A gas that has a critical temperature below -10°C.
• (In everyday terms a gas that cannot be liquefied by increasing pressure at ambient temperatures e.g. oxygen, nitrogen, argon). 50°C

What is vapour?

vapour means a gaseous form of a hazardous substance released from its liquid or solid state

What is a class 2 substance ?

• compressed gases,
• liquefied gases,
• dissolved gases,
• refrigerated liquefied gases,
• mixtures of gases and aerosol dispensers/articles containing gas.

There are 3 sub-divisions:

• Division 2.1: Flammable gases
• Division 2.2: A gas which is non-flammable, non-toxic, non-oxidising, and is resistant to chemical action under normally encountered conditions
• Division 2.3: Toxic gases are known to be so toxic or corrosive to humans as to pose am hazard to health; or are presumed to be toxic or corrosive to humans because they have an LC50 value (as defined in 2.6.2.1) equal to or less than 5,000 ml/m3 (ppm).

Which are the most common class 2.1 flammable gasses ?

Ignitable at 13% volume in air or have a flammable range with air of 12%, regardless of LFL

LPG Silver Cylinder

• Flammable Extremely hazardous
• ‘Stenched’ (odourised) and has a distinctive odour
• Will ignite and burn instantly from a spark or piece of hot metal
• Heavier than air and will collect in ducts, drains etc., and low lying areas
• Fire and explosion hazard
• Highly flammable
• Must Eliminate all ignition sources near the substances

What is LPG?

LPG means liquefied petroleum gas

Acetylene Maroon cylinder

• Flammable Extremely hazardous
• Distinctive garlic smell
• Fire and explosion hazards are greater than LPG but it is slightly lighter than air and less likely to collect in ducts and drains
• Requires minimal energy to ignite in air or oxygen
• DO NOT use with copper or high copper brass alloys because copper materials form explosive compounds with Acetylene

Hydrogen Signal Red cylinder

• Flammable Extremely hazardous
• Odourless
• Much lighter than air and will collect at the highest point in any enclosed space unless ventilated at high level
• Fire and explosion hazard
• Very low ignition energy
• Burns with an invisible flame

Which are the most common class 2.1.2 gasses?

Pressurised mixture containing a gas, compressed, liquefied, or dissolved under pressure; comprising 5%, by mass, flammable ingredients; under a pressure > 100 kPa

Aerosols; some fly sprays and spray paints

Which are the most common class 2.2 non-flammable, non-toxic, non-oxidising gasses?

Nitrogen, compressed or liquefied Black cylinder

Is commonly used in refrigeration, automotive, hydraulics, aviation and metal processing, and as an assist gas for laser cutting stainless steel. It is ideal for blanketing or purging, displacing or diluting other gas vapours.

Oxygen, compressed or liquefied – white cylinder

• The main industrial application for oxygen is combustion efficiency.
• As combined with a fuel gas it will produce much higher flame temperature
  It is used in conjunction with acetylene and LPG for brazing, glass blowing and cutting.
• It is also used in conjunction with acetylene for welding and LPG for brazing, glass blowing and jewellery manufacture.
• Other uses include beer brewing and fish tank oxygenation.

Carbon dioxide, compressed or liquefied –grey cylinder

CO2 is commonly used as a shielding gas for MIG welding steel up to 10mm, welding carbon and alloy steel, and stainless steel with flux cored wires.

Nitrous oxide, compressed – blue cylinder

Is used especially as an anesthetic in dentistry and as a fuel, and that is an atmospheric pollutant and greenhouse gas produced by combustion.

Argon Peacock Blue cylinder

• Odourless
• Asphyxiant
• At high concentrations almost instant unconsciousness may occur, followed by death
• No warning signs before unconsciousness occurs
• Argon is heavier than air
• Does not burn
• Inert

Which are the most common Class 2.3: Toxic gases?

Ethylene oxide (sterilising gas)

EtO is found in the production of solvents, antifreeze, textiles, detergents, adhesives, polyurethane foam, and pharmaceuticals.

Chlorine, compressed or liquefied 

• Its most important use is as a bleach in the manufacture of paper and cloth
• used to make pesticides (insect killers), rubber, and solvents.
• Chlorine is used in drinking water and swimming pool water to kill harmful bacteria.

Ammonia, anhydrous, liquefied

• Ammonia is used in wastewater treatment, leather, rubber, paper, food and beverage industries.
• It also is used cold storage or refrigeration systems
• in the production of pharmaceuticals
• Ammonia is used in the printing as well as cosmetics industries.
• It is also used in fermentation

Sulfur dioxide, compressed or liquefied

Although its chief uses are in the preparation of sulfuric acid, sulfur trioxide, and sulfites,

• is used as a disinfectant,
• a refrigerant,
• a reducing agent,
• a bleach,
• a food preservative, especially in dried fruits.