Spill Bund 101: What Bunding Does Your Workplace Require?

Aug 25, 2021 Posted by Walter Ingles

To manage the hazards associated with chemical spills, bunding is required as part of your secondary containment strategy. Put simply, a spill bund is an embankment or wall that form part, or all, of the perimeter of your spill containment area. Examples of bunding systems commonly used in workplaces can include steel bunds, floor bunds, drum bunds, intermediate bulk container bunds, bunded storage and bunded shelving — to name just some of the many solutions on the market.  

In this blog, we look at the hazards associated with chemical spills and explain why the dangerous goods classification of the chemical that you are storing is the first step in determining what bunds you’ll need. 

Hazards Associated with Chemical Spills and Leaks

Spills and leaks within the workplace can result in a range of serious issues including: 

  • Health hazards – people are harmed due to contact with the chemical spill, leak and/or associated vapours 
  • Property damage – chemicals such as flammable liquids, explosives and compressed gases can cause extensive damage to property  
  • Risk of fire and explosion – certain chemicals can catch on fire or explode if they are near an ignition source 
  • Water pollution – if secondary containment measures are not employed, chemicals can enter the water systems through drains or seepage 
  • Soil contamination – chemical spills can seep into the soil and contaminate the environment 

Types Of Bund Products

There are a variety of spill containment bunds with temporary and permanent options available.  

Some types of bunds commonly found in Australian workplaces include: 

Your choice of bund will be determined by the class of dangerous goods that you are using and storing in your organisation, as well as the individual requirements of your operation. 

Most organisations will have to use a variety of bunding products to provide a complete secondary containment solution for their workplace. 

The EPA recommends that bunding and secondary containment measures are determined on a site-by-site basis. This ensures that they are meeting the needs of the organisation and that the bunding solutions are compliant with WHS regulations. 

Regulations For Spills and Dangers 

Regarding the containment and management of chemical spills in the workplace, Australian businesses are bound by law to comply with WHS Regulations. 

The WHS Regulation states that: 

Subdivision 2 Spills and Damage

357 Containing and managing spills  

  1. A person conducting a business or undertaking at a workplace must ensure, so far as is reasonably practicable, that where there is a risk from a spill or leak of a hazardous chemical in a solid or liquid form, provision is made in each part of the workplace where the hazardous chemical is used, handled, generated or stored for a spill containment system that contains within the workplace any part of the hazardous chemical that spills or leaks, and any resulting effluent.  

According to the WHS Regulations, provision must be made in workplaces to ensure a spill containment system is utilised where there is a risk from a spill or leak of a hazardous chemical.  

Individuals can face fines up to $6 000 and body corporates up to $30 000 if the spill is not adequately contained. 

Bunding For Flammable or Combustible Substances 

Bunding is designed to not only contain spills, but to prevent further workplace hazards from occurring. When dealing with flammable or combustible substances, the chemical spill can quickly travel — increasing the potential for hazard by coming into contact with possible ignition sources such as flames and hot surfaces as well as electrical, mechanical or chemical ignition sources. Common workplace equipment such as electric motors, soldering irons equipment and even stoves can be an ignition source for flammable chemical substances.   

As well as the risks involved with damage to property and the environment, there are serious health hazards involved with chemical spills and leaks. Chemicals may be accidently inhaled, ingested, splashed into eyes or absorbed through the skin when a spillage occurs, which puts the people in your organisation at risk of acute health effects. 

If your organisation works with or stores flammable liquids or combustible substances, you must manage the risks involved with chemical spills. You are required by law to devise a secondary containment plan, and apply the appropriate bunding products to your secondary containment areas. 

Steel Bunds Vs Polyethylene Bunds

As secondary containment and bunding is a legal required as stated in WHS Regulation, it’s important to make the provision for a bunding solution that is safe and compliant. 

Spill bunds may be manufactured from steel (metal bunds) or polyethylene (plastic bunds), with each bunding material suiting a specific class of dangerous goods. 

Steel Bund Applications 

The Australian Standard (AS 1940-2017) details the requirements for storage and handling of flammable and combustible liquids.  

In reference to the spill containment of flammable liquids, AS 1940-2017 states: 

4.4.3 Spillage containment 

Provision shall be made to contain any leaks or spillages, and to prevent them from 

contaminating the surrounding soil or entering any watercourse or water drainage system. 


The following requirements apply: 


(a) A spillage containment compound shall be sufficiently impervious to retain spillage 

and to enable recovery of any such spillage. The compound shall be chemically 

resistant and fire resistant as far as is necessary to fulfil its functions. 


NOTE: Portable bunding units, e.g. bunded pallets, or flexible bunding units are not suitable for permanent storage as there are no uniform performance criteria for chemical resistance or fire resistance and they can be easily moved to an unsuitable location. They may be suitable for the short-term holding of damaged packages, or where goods are in transit or in manufacturing and handling areas. 

According to the standard, if flammable liquids are used or stored in your workplace, bunds must be chemically and fire-resistant with the substance being stored. 

Therefore, when choosing bunds for this type of spillage containment compound, you should focus on permanent bunding solutions instead of temporary bunds such as portable or collapsible bunds – which are designed for remote worksites or temporary storage facilities.  

Steel bunds are suitable for the storage of: 

  • Flammable Liquids 
  • Toxic Substances 
  • Oxidising Agents 
  • Organic Peroxides 

NOTE: If steel bund systems (such as a heavy duty steel bund) are custom made with corrosive resistant sump liners, they can be used to store corrosive substances. 

Polyethylene Bund Applications 

According to the Australian Standard (AS 3780-2008) for the storage and handling of corrosive substances, corrosives are: 

Substances that, by chemical action, will cause severe damage when in contact with living tissue, or in the case of leakage, will materially damage, or even destroy, other goods or the means of transport; they may also cause other hazards. Such substances are listed as Class 8 corrosive substances in the ADG Code or meet the classification criteria specified in that Code for corrosive substances. 

The standard states the requirements for bunds and containment compounds when managing the risks of corrosive substances spills and leaks: 


5.4.3 Design and construction  

Compounds and, where they are provided, bunds shall comply with the following requirements:  

(a) The materials of construction shall be substantially immune to attack by any corrosive substance that they may be required to contain.  
(b) They shall be sufficiently impervious to retain and to enable the recovery of any spillage.

Polyethylene bunds are suitable for the storage of: 

  • Corrosive Substances 
  • Toxic Substances 
  • Oxidising Agents 
  • Organic Peroxides

Selecting Spill Bunds By Dangerous Goods Class

To summarise information from the Australian Standard, if you are storing flammable liquids, they must be kept in steel bunds to prevent a fire hazard. 

If you are storing corrosive substances, you will need to make sure that the bund will not succumb to a chemical attack caused by the corrosive chemical. Therefore, polyethylene bunds are suitable for the safe storage of corrosive substances, as well as other non-flammable substances.  

Is Your Bunding Compliant?

Secondary containment and bunding is an essential element of your spill and leak prevention plan. To manage the risks posed by hazardous substances at your workplace, you must first understand what dangerous goods you are carrying and then implement a secondary containment plan that is compliantThe class of dangerous goods that you are storing, such as flammable liquids, will determine the products that you select. If you’d like to learn more about bunds and how to prevent the hazards associated with chemical spills, you can download our FREE eBook. Essential Considerations When Storing Flammable Liquids Indoors contains details about how to select, install and maintain an indoor safety cabinet that’s been manufactured to AS1940:2017 – The storage and handling of flammable and combustible liquids. Click on the image below to access it today. 

Essential Considerations when Storing Flammable Liquids Indoors download Free eBook

Walter Ingles

Walter Ingles Compliance Specialist

Walter is STOREMASTA’s Dangerous Goods Storage Specialist. He helps organisations reduce risk and improve efficiencies in the storage and management of dangerous goods and hazardous chemicals.

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