Spill Control & Secondary Containment: Code Basics & Solutions

Many of Hallam-ICS’s clients use hazardous materials as part of their process. Statutory codes provide several requirements depending on the material properties and quantities of hazardous materials. This blog focuses on the requirements for spill control and secondary containment.

This blog outlines the code requirements for secondary containment and spill control when handling hazardous materials. It compares  editions of the International Fire Code (IFC) and NFPA 1/NFPA 400, explaining when and how these requirements apply. You’ll also find practical examples of containment solutions used in industrial facilities to help you evaluate or design compliant systems.

Statutory Codes

The codes in effect in the United States differ by state and municipality. In general, the fire code in effect is an edition of one of the following:

1. International Fire Code (IFC) as published by the International Code Council (ICC).
2. NFPA 1: Fire Code as published by the National Fire Protection Association (NFPA).
   1. NFPA 1 references NFPA 400 for sites where quantities of hazardous materials exceed the Maximum Allowable Quantity.

Both organizations publish an edition of their fire code every three years. Municipalities then adopt a specific edition, usually with some modifications.

For the purposes of this article, I will focus on the 2021 editions of both fire codes. It is important to check which edition of which is statutory for your facility and if there are any modifications by your local municipality.

What are Secondary Containment and Spill Control?

These two terms are often confused because the solution for spill control and secondary containment is often a single solution.

Spill Control

Spill control refers to controlling liquid spread in the event of a container tipping or otherwise spilling. Some common examples:

1. Tipping and spilling the contents of a container.
2. Spilling a container while transferring material.

Secondary Containment

Secondary containment refers to controlling the contents of tanks or piping in the event of a mechanical failure. This could be a tank, valve, pipe, fitting, or other component. Some common examples:

• Primary tank failure.
• Pipe flange leak.
• Pipe break.
• Valve or fitting leak.

Fire Protection Water and Rainfall Containment

Where codes require secondary containment, they may also require containing additional water that may enter the containment. This is to prevent the runoff of hazardous materials to other building areas and to the exterior. The requirements for this are:

• Fire protection water
  1. A minimum of 20 minutes of fire protection water for indoor storage, use, dispensing, and handling areas.
  2. The volume required for this additional containment depends on the sprinkler design. For ordinary hazard group 1 or 2, the maximum flow rate is 0.20 gpm/ft² which equates to 6.4 inches of additional containment height.
• Rainfall
  1. The International Fire Code (IFC) requires containing 24-hours of rainfall of a 25-year storm for outdoor storage, use, dispensing, and handling areas open to rainfall.
  2. NFPA 400 does not require containing rainfall, but it is good practice.

Where Required

The requirement for spill control and secondary containment depends on the quantities of materials stored compared to the Maximum Allowable Quantity (MAQ) for that material. In general, statutory codes require both spill control and secondary containment for quantities exceeding the Maximum Allowable Quantity for that material. 

Key Spill Control and Containment Requirements by Code and Volume Thresholds

Code Path

If you need to review these code requirements for your own project the following will help point you in the right direction.

Both fire codes have similar logic to requiring spill control and secondary containment, but the code path is different.

• 2021 International Fire Code (IFC)
  1. Chapter 50, “Hazardous Materials-General Provisions,” provides requirements for hazardous materials.
  2. Section 5003.1.3 requires following sections 5001 through 5003 for quantities not exceeding Maximum Allowable Quantities (MAQs).
  3. Section 5003.1.4 requires following all of chapter 50 including 5004 and 5005 for quantities exceeding Maximum Allowable Quantities (MAQs).
  4. Sections 5004 and 5005 provide requirements for spill control and secondary containment.
• 2021 NFPA 1: Fire Code
  1. Chapter 60, “Hazardous Materials,” provides requirements for hazardous materials.
  2. Section 60.4.1.1 allows storage and use of hazardous materials in the following ways:
     1. In quantities not exceeding Maximum Allowable Quantities (MAQs).
     2. In quantities exceeding Maximum Allowable Quantities (MAQs) indoors following 60.4.3 which requires following NFPA 400 chapters 6 and 11 through 21.
     3. In quantities exceeding Maximum Allowable Quantities (MAQs) for outdoor locations following 60.4.4 which requires following NFPA 400 chapters 6 and 11 through 21.
• NFPA 400 chapter 6 provides requirements for spill control and secondary containment.

Common Solutions

There are many solutions for spill control and secondary containment. This section shows some of the more common solutions with generic examples. Note that there are often variations to these that work better for different projects.

Double Walled Tanks

These are tanks specifically constructed to contain a leak if the primary tank fails.

This design is often compact but can be complex. Depending on the material there are additional code requirements and best practices. For example, a bottom connection on the tank is a single point of failure for the tank. Generally piping connections should be located on the top of the tank, and the design should incorporate a method to prevent siphoning liquid from the tank.

Figure 1: Double Walled Tank

Containment Berms

Containment berms are a common solution. These are often constructed of concrete. If the area surrounding the tank area is large, this berm often does not need to be very high.

Several products exist to provide temporary berms for operations such as portable tank or truck loading.

Figure 2: Containment Berm

Sloped Flooring

For smaller quantities of material, the storage room floor can be sloped and sealed so a spill will stay within the room. Depending on the room size, this is often a simple cost effective solution. Note that this solution alone does not provide fire protection water containment.

Figure 3: Sloped Flooring

Recessed Flooring

Providing a lower floor than the surrounding area can contain liquids. Depending on the height of this recess this can also contain fire protection water.

The entry to this room will require a ramp or step. This requires coordination with the architect.

Figure 4: Recessed Flooring

Grated Floor with Containment Below

For this strategy the walking surface is grating with solid surface below the grating. The solid surface often slopes toward a low point for cleaning or pumping.

One major drawback to this strategy is that the area below the grating is difficult to safely access for piping modifications or cleaning.

Figure 5: Grated Floor With Containment Below

Pop-Up Spill Barrier

Several vendors offer pop-up spill barriers intended to prevent spills from exiting through a doorway. With this solution, the product is recessed into the floor. If liquid enters the product, it causes a containment berm to rise and block liquid from passing through the doorway.

Figure 6: Pop-Up Spill Barrier

Low Point Containment

This solution drains liquids in the space to a low point in the room. There are several options for this low point:

1. Recessed space with no drainage
2. Floor drain or trench drain
   1. For this solution, the design should consider where hazardous materials will flow in the event of a spill and where fire protection water will flow in the event of a release. Often the solution is a separate underground tank. If liquid enters this tank, the facility owner can test and dispose of the liquid safely after a release.

Figure 7: Low Point Containment

Understanding and applying code requirements for secondary containment and spill control is essential to ensure safety, regulatory compliance, and environmental protection. If you're planning a new facility, reviewing existing infrastructure, or navigating code requirements for hazardous materials, Hallam-ICS can help. Contact our team to discuss your project needs or schedule a code compliance review with one of our experts.

About the Author

Ash Kreider is a Mechanical Engineer at Hallam-ICS. He has process engineering experience in multiple industries. He currently designs systems for a wide range of applications including gas distribution, cryogenic fluid recovery, process equipment hookup and HVAC.

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About Hallam-ICS

Hallam-ICS is an engineering and automation company that designs MEP systems for facilities and plants, engineers control and automation solutions, and ensures safety and regulatory compliance through arc flash studies, commissioning, and validation. Our offices are located in Massachusetts, Connecticut, New York, Vermont and North Carolina  Texas, Florida and our projects take us world-wide.