Chemical bunds are used when handling or storing hazardous liquids as a means to protect the surrounding area and people from contamination.  There are several considerations to take into account when selecting chemical bunds, such as the type of chemicals you’ll be storing and the environment in which the bund will be used.

We frequently receive questions about the purpose, importance, maintenance and requirements for chemical bunds. To help you understand everything you need to know about bunds, we’ve developed the complete guide which answers all of your FAQ’s.

What is a chemical bund?

A bund is essentially a large tray into which or on which you sit your chemical containers or drums, so that if they leak the spilled chemical is captured and retained in the chemical bund. The bund should capture a leak which might otherwise go unnoticed. Bunds are required under chemical storage tanks or drum storage areas where chemicals, hazardous substances, flammable or toxic liquids are held.

Why should I use IBC bunds or pallet bunds?

Storing your IBCs, drums or containers on chemical bunds ensures that any major spill or incidental leaks are contained before they hit the ground. Chemical bunds protect the environment, the workplace and importantly, your employees and customers, from contact with any hazardous material stored in your containers.

What size chemical bund do I need?

Bunds should be sized to hold 110% of the maximum capacity of the largest tank or drum in the chemical store. This will allow some additional space for the addition of foam during emergency response. In Chemical stores with multiple containers/drums stored, the bund capacity should be 110% of the volume of the largest container or 25% of the total volume stored – whichever is the larger. Incompatible substances should always have separate bunds.

What are bunds made from?

Bunds typically feature a moulded plastic or steel construction. Plastic bunds are usually manufactured from low density polyethylene (LDPE) which is the same material that the chemical drums, containers and IBCs are manufactured from.

Plastic chemical bunds are normally static and are not usually stable enough to be transported on forklifts. If you need to be able to transport your chemical containers by forklift and the chemicals contained are not corrosive, then you should choose steel bunds. If you are storing corrosive chemicals, you should choose a plastic bund or a plastic bund liner in a steel bund.

Why should chemical bunds be tested?

In order to comply with U.K. legislation, all bunds must pass a “Bund Integrity Test” at least every 3 years. As bunds can contain high risk material, you need to be confident that they are undamaged and will still contain a chemical spill.

Are there any U.K. legislative requirements regarding chemical bunds?

Using chemical bunds as a form of secondary containment is recommended in numerous U.K. codes of chemical safety practice. All hazardous substances, be it oil, chemicals or liquid waste, must be stored on chemical bunds which are a minimum 110% of the capacity of the largest container stored in the area.

In HS(G)71 Chemical warehousing: the storage of packaged dangerous substances, HSE, 199,
Paragraph 108 recommends bunds are used to ensure segregation of incompatible materials should leaks occur. HS(G)176 The storage of flammable liquids in tanks also recommends individual bunds are used for large flammables storage units. Other important, relevant pieces of U.K. legislation include PPG26 – Storage and Handling Chemical Drums & IBC’s and HS(G)51 – The Storage of Flammable Liquids in Containers.

Do I need to maintain a chemical bund?

Maintenance of chemical storage bunds is very important, especially for external uncovered bunds which are open to the elements and will fill with rainwater. However, maintenance is often overlooked. The bund should be routinely inspected, and efforts made to maintain the integrity of the bund.

Drainage of external bunds is particularly important to allow the removal of rainwater. Failure to remove rainwater will reduce the capacity of the bund and could cause water to mix with incompatible chemicals.

Which chemical bund is right for me?

Many people immediately think that a steel bund is a superior bund, but this is not always the case. It really depends on the application and environment in which the bund will be used. At Safety Storage Systems we have over 20 years of experience with handing and storing hazardous chemicals. If you are unsure about which chemical bund you should use in your facility, reach out to one of our experts or check out some of our other articles.

Want to learn more about chemical safety?  Read our chemical storage principles and best practices guide.