What is Secondary Containment and When is it Required?

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December 1, 2019
 

What is secondary containment?

A primary container is the vessel that holds the hazardous substance, for example a bottle, 20L container, 200L drum or 1,000L IBC (intermediate bulk container). Secondary containment could be best described as the system in place to contain spills, leaks or the failure of the primary container stored on it.

 

Why is it required?

In the many workplaces storing or using hazardous substances, the primary containers that hold such liquids are vulnerable to damage. This vulnerability can come from poor storage practices, mismanaged decanting or transfer procedures, or damage from vehicles such as forklifts.

A secondary containment system is often required to contain these hazardous liquids if they escape from the primary container, and to prevent them from escaping into the wider environment.

That environment might be the immediate workplace and therefore may put employees and other personnel at risk. Or it might be a nearby waterway which will quickly pollute and impact marine and bird life, as well as their ability to be used for domestic, commercial or recreational purposes.

 

How is it achieved?

Secondary containment has been historically achieved by building ‘berms’ from concrete or block walls, earth mounds or large tubs.  In recent years however, it has been made much less complex with low profile work floors, spill containment pallets and flexible bunding options. These are designed to be quickly repositioned as your site and operational requirements change over time.

 

At what point is it required?

The point at which your worksite requires secondary containment depends on what class of liquids you have on site, and in what quantities.  For really hazardous liquids, it is required from very low levels. For others, you are allowed to have a larger amount before secondary containment is required, while for many non-hazardous substances, little to none may be needed at all.

While not exhaustive, the below table details some of the more common classes, and at what point secondary containment is required:

Hazard Classification
Amounts Where the Need For Secondary Containment Is Triggered:

Class 5.1.1A

50L

Class 5.1.1B

500L

Class 5.2A, 5.2B

10L

Class 5.2C, 5.2D

25L

Class 5.2E, 5.2F

100L

Class 6.1A, 6.1B, 6.1C

100L

Class 6.1D, 6.5A, 6.5B, 6.7A

1,000L

Class 8.2A

100L

Class 8.2B

1,000L

Class 8.2C, 8.3A

10,000L

Class 9.1A

100L

Class 9.1B, 9.1C

1,000L

Class 9.1D

10,000L

 

Further information including classes beyond those listed above, visit the WorkSafe website.  

 

What level of secondary containment is required if the above amounts are triggered?

The below table is a summary of the requirement levels for secondary containment, as per the Health & Safety at Work (Hazardous Substances) Regulations 2017:

Requirements for Class 1-5:
Container size
Total pooling potential
Secondary containment capacity

Up to 60L

Less than 5,000L

At least 50% of the total

5,000L or more

2,500L or 25% of the total*

More than 60L and up to 450L

Less than 5,000L

At least that total potential

5,000L or more

5,000L or 50% of the total*

More than 450L

Less than 5,000L

At least that total potential

5,000L or more

5,000L or 50% of the total*

 

Requirements for Class 6-9: 
Container size
Total pooling potential
Secondary containment capacity

Up to 60L

Less than 20,000L

At least 25% of the total

20,000L or more

5% of the total or 5,000L*

More than 60L and up to 450L

Less than 20,000L

25% of the total,or 110% of the capacity of the largest container*

20,000L or more

5% of the total or 5,000L*

More than 450L

Less than 20,000L

25% of the total,or 110% of the capacity of the largest container*

20,000L or more

5% of the total or 5,000L*

*whichever is greater

This is a summary of Regulations 13.30, 13.31, 13.32 and 13.33 of the abovementioned Regulations and should be used as a guide in the context of all other components within it.

 

Creating safer working environments

At Hazero our mission is zero hazards. Our extensive range of quality products will help you storecontain and control and clean-up dangerous goods and hazardous substances.

View our full range of Controlco secondary containment products here.

Need help creating a safer working environment? Contact our team today on 0800 688 844 or email us at info@hazero.co.nz. Our team are also available for on-site assessments across New Zealand, click here to request a site visit.

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