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Dangerous Goods Classes & Regulations - Flammable Solids

An in-depth look at one of the nine classes of dangerous and hazardous goods: Class 4 – Flammable Solids

Shipping Class 4 Dangerous Goods

There are a total of nine dangerous/hazardous goods that we use within the logistics industry. Each product, when transported, can pose risk to safety – whether that be to personal health or environmentally. Depending on the type of damage said product deals and what they are formed of, they are divided into one of the nine classes.

On the Tudor website you will find information in respect of each class of the nine classes of dangerous goods. If you want a full overview of the dangerous goods topic before delving in to the specifics, be sure to check out our previous blog here.


What is a Class 4 Dangerous Good?

Class 4 Dangerous Goods are flammable solids.This category of hazardous cargo represents substances which are liable to spontaneous combustion and goods that emit flammable gases when they come into contact with water.

Metal powders are particularly hazardous as they are more difficult to extinguish when on fire. A lot of extinguishers contain Carbon Dioxide or water; however, both of these could increase the danger when used on a flammable metal.

If you are looking for Flammable Liquids, you can read our blog about those instead, here.


Class 4: Flammable Solids – Sub Divisions:

Like the majority of the classes of dangerous goods and as briefly touched on above, flammable solids are also placed into their own sub-divisions, in which there are three.

Division 4.1: Flammable solids

Goods that fall under division 4.1 will burn extremely easily, much easier than your ordinary combustible material such as wood and paper. In fact, some items that fall under sub division 4.1 are desensitised explosives such as trinitrotoluene (TNT). . Without the densitisation, products such as TNT would fall under Class 1 – Explosives.


Division 4.2: Substances liable to spontaneously combust

Division 4.2 can be complex in that these goods can be either solids or liquids. Dissimilar to Class 3 however, these will ignite spontaneously when in contact with oxygen. These materials need to be kept in airtight packages or as liquids under an inert gas/liquid blanket at all times.


Division 4.3: Dangerous when wet (Substances that emit flammable gases when they come into contact with water)

Division 4.3 hazardous goods do exactly as they say on the tin, they react with water and become dangerous when wet, generating flammable gas. This gas can be ignited by the heat of the reaction and must be kept in watertight containers that are hermetically sealed to avoid the entry of moisture or water vapour.


Flammable Solids Sign

There are three commonly used dangerous goods labels that you are likely to see used for flammable solids. Each signage is significant to one of the three sub divisions noted above; Division 4.1, Division 4.2 and Division 4.3. All the labels can be seen pictured below.



Do Any of Your Goods Fall Into The Category of Class 4: Dangerous Goods?

Commonly Transported Class 4 - Flammable Solids:

  • Sulphur
  • Matches 
  • Sodium Batteries
  • Alkali Metals
  • Certain Metal Powders


If you have any other questions or concerns surrounding Dangerous Goods or Flammable Solids as a specific, or are just unsure what category your goods fall under, please do not hesitate to get in touch and we will be happy to help -

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