Chemical bunding is a key part of any spill containment system and is designed to protect your organisation and the environment from the hazards associated with chemical spills. But just like any risk control method, there is a right way to select, install and maintain bunding — and there also is a wrong way. In this blog, we look at 4 common chemical bunding issues and explain how you can rectify any non-compliant practices in your workplace.
Issue #1: Chemical Incompatibility
When you’re working with hazardous substances such as corrosives, flammables, toxic substances or organic peroxides, your spill containment and management system will be determined by the class of dangerous goods that you are carrying.
This is because each class of dangerous goods has its own set of physical and chemical properties —and these may react with certain substances, chemicals or materials. Because of chemical compatibility issues, the dangerous goods class of your chemicals will determine the materials that your bunding — and other risk control measures — are constructed from.
To further explain, the Australian Standard AS 1940:2017 - The storage and handling of flammable and combustible liquids states the requirements for bunds and spill compounds for those organisations who have flammable liquids. There are specific sections of the standard that refer to the way your flammables are stored — either in package stores or tank storage.
If you're holding your flammables in package stores, refer to Section 4 of AS 1940:2017:
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.
However, if your flammable liquids are stored in tanks, the following requirements in Section 5 of the standard apply:
5.8 BUNDS AND COMPOUNDS
5.8.3 Design and construction
A compound and its associated bund shall comply with the following requirements:
(a) It shall be sufficiently impervious to retain spillage and to enable recovery of any such spillage; buried HDPE, geosynthetic clay liners, concrete or other equivalent materials are deemed to be suitable materials. When earthen bunds are used, consideration shall be given to the minimization of penetration of the bund surface, because of permeability, in the event of a spill.
(b) In a fire situation, the bund shall retain the structural integrity, which includes any bund wall joints and penetrations. Such joints and penetrations shall include suitable fire resistant fillers in combination with metal waterstops.
To summarise Section 4.4.3 and 5.8.3 of the standard, if you’re carrying flammable liquids at your organisation, your bunding and spill containment compounds must be able to retain chemicals, aid in the recovery of spillage, and retain structural integrity in the event of a fire.
So, when you’re selecting your chemical bunding for your flammables, you should choose steel bunding which is manufactured to meet the requirements of AS 1940:2017. Polyethylene (plastic) bunds won’t be a compliant choice for flammable liquid spill containment.
Issue #2: Unprotected Work Areas
According to the Model Work Health and Safety Regulations, wherever there is a risk from a leak or spill of a hazardous chemical, an organisation must provide a spill containment system.
This means that spill containment issues need to address in each part of the workplace where the hazardous chemical is:
For example, you may have bunded storage and floor bunding installed in your workshop, but if you’re working with hazardous chemicals and moving them between other work areas – then you must also consider the spill bunding requirements of those workspaces.
Chemical bunding can be used in all indoor and outdoor areas of the workplace where hazardous chemicals are present.
These may include:
- Loading docks or delivery/receiving areas
- All areas where chemical decanting occurs
- Storage areas for hazardous chemicals
- Manufacturing premises
- Waste management areas
- Any work area where chemicals are transferred to, from or through
Conducting a detailed risk assessment of your workplace will help you identify all the areas where you are required to provide bunding and spill containment.
REMEMBER: If you’re using, handling, generating or storing hazardous chemicals, WHS Regulations states that you have a legal obligation to provide a compliant spill containment system.
Issue #3: Incorrect Bund Capacity
Are you confident that your chemical bunding complies with the capacities set out in the Australian Standards? It’s not just as simple as allowing for 110% capacity of your largest container (although you’ll often read that online).
To properly determine the bunding capacity for your workplace, we recommend an onsite risk assessment. However, the Australian Standard that relates to the chemicals that you’re carrying does detail the exact capacity requirements that you need to adhere to.
To help you along, we’ve summarised the spill containment capacity regulations for some common classes of dangerous goods that may be found at your workplace.
Class 3 Flammable Liquids
If your organisation carries flammable liquids, the required capacities are outlined in AS 1940:2017 – The storage and handling of flammable and combustible liquids. The standard explains that the capacity must be a minimum of 100% of the volume of the largest flammable liquids package. Plus, you must allow 25% of the storage capacity (up to 10 000 L, together with 10% of the storage capacity (10 000 – 100 000 L) and 5% (above 100 000 L).
Class 5.1 Oxidizing Agents
The Australian Standard AS 4326:2008 – The storage and handling of oxidizing agents is your go-to reference if your organisation carries any type of oxidizing agents. The standard explains that the containment area needs to be capable of holding 100% of the aggregate volume of PG 1 liquids, and 25% of the aggregate volume of PG II or III liquids.
Class 5.2 Organic Peroxides
Does your workplace handle or store organic peroxides? AS 2714:2008 – The storage and handling of organic peroxides explains that spill containment capacity should be at least 25% of the volume of liquid organic peroxides stored or the capacity of the largest container (whichever is greater).
Class 6 Toxic Substances
AS/NZS 4452-1997 – The storage and handling of toxic substances provides details for the spill containment capacity for PG I and PG II and III toxic substances. The net capacity of the spill compound should be 100% of the aggregate volume of PG I liquids kept and 25% of the aggregate volume of PG II and III liquids kept.
Class 8 Corrosive Substances
If your workplace has corrosive substances, you should refer to AS 3780:2008 – The storage and handling of corrosive substances. The standard states that the capacity of the spill compound should not be less than 25% of the aggregate volume of liquids kept or the capacity of the largest container kept (whichever is greater). The compound should not exceed 5000 L where only packages are kept.
REMEMBER: When calculating chemical bunding capacities, you should also factor in the volume of water that is dispersed by firefighting equipment in the event of a workplace fire.
Issue #4: Inadequate Maintenance Of Bunds
Spill containment systems are designed to provide a short-term solution to chemical spills and leaks. But what they’re not designed to do is hold spilt substances for longer periods of time. One of the most important things to remember after you’ve implemented spill bunding at your workplace is that you must regularly inspect, clean and maintain it.
If you have bunded storage with a spill sump, you must make sure than any chemicals in the sump are immediately cleared and discarded in a safe way. Spilt chemicals pose an array of risks due to the hazardous vapours that they emit. If they aren’t dealt with promptly by your team, the chemicals could cause serious hazards such as human harm, fire or explosion.
The effectiveness of the sump will also be compromised, as the sump is specifically designed to hold a certain capacity of spilt chemicals. This sump capacity does not include the volume of spilt chemicals that are already sitting in the sump.
It’s important to maintain a regular schedule of inspections, maintenance and housekeeping to ensure your spill containment measures stay compliant. Make sure that any chemical leaks and spills are cleaned up straight away, so your bunding can continue to provide a safe and compliant spill containment solution.
Are You Curious About Compliant Chemical Bunding?
We’ve shared 4 of the common chemical bunding issues found in workplaces and offered some advice on how to correct any of these serious compliance issues. But if you’re still curious about how to choose, install or maintain chemical bunding, our team at STOREMASTA can help. We’ve put together a helpful eBook that will assist you in controlling chemical hazards at your workplace. By adopting our 4-Step risk management methodology that’s detailed in Controlling Risks Associated With Hazardous Chemicals, you can systematically reduce the risks and hazards in your workplace. Click on the image below to access it for free today.