What Is Secondary Containment? Understanding OSHA and EPA Regulations

Key Takeaways

• Secondary containment serves as a backup to prevent hazardous materials from spreading if the primary container fails, and it’s relevant to both large- and small-scale operations.
• OSHA and EPA secondary containment requirements are triggered by specific scenarios, such as the storage of flammable liquids, hazardous waste, or oil, each with distinct thresholds and enforcement criteria.
• Choosing the right types of secondary containment depends on the material, volume, and setup, with systems like berms, drip pans, and spill pallets commonly used across industries.
• Noncompliance, whether due to missing systems, poor maintenance, or overlooked small-scale risks, can lead to serious fines and health hazards, even without a major spill.

What Is Secondary Containment?

I’ve heard more than a few people say secondary containment is only something big industrial sites need to worry about. But the truth is, I’ve seen small operations get hit just as hard when a single leak goes unchecked. It doesn’t take a massive spill to cause serious damage—financial or environmental.

So what is secondary containment, really?

It’s the backup plan. A system or setup that catches or contains hazardous material if the primary container—like a drum, tank, or tote—leaks, cracks, or fails. Think of it as a safety net under a tightrope. You hope you never need it, but when things go sideways, it keeps everything from hitting the ground.

Smaller leaks are often the real troublemakers. They sneak past attention, especially in busy warehouses or storage rooms where chemicals are stacked on shelves. I’ve walked through spaces where five-gallon buckets of solvent sat unsecured on warped wooden shelves—no spill containment, no liners, nothing. That’s the kind of setup where one bumped shelf can turn into a major incident.

Secondary containment is not a formality. It must be functional and maintained. A system that sits in place without regular inspection or upkeep offers no real protection.

Who Needs Secondary Containment?

In 2019, the Environmental Protection Agency (EPA) estimated that around 550,900 facilities in the U.S. would fall under SPCC regulations. That number reflects how common secondary containment needs really are, and that it’s not limited to chemical plants or oil terminals. A wide range of operations, across many sectors, are expected to prevent spills before they spread.

The question isn’t whether your industry sounds high-risk. It’s whether you store, handle, or move materials that could cause harm if released. Many facilities miss the mark not because of intent, but because they don’t realize containment applies to their setup.

Below is an overview of key industries and the common hazardous materials they use:

Each of these industries deals with substances that pose significant risks if released into the environment. Implementing appropriate secondary containment measures is not simply a regulatory requirement but a critical component of responsible environmental stewardship.

For waste management facilities, proper containment is particularly crucial due to the diverse nature of hazardous wastes handled. According to the Washington State Department of Ecology, businesses generating dangerous waste must use containers that are compatible with the waste, properly labeled, and stored with appropriate secondary containment to prevent leaks and spills, as shown in the image below.

Types of Secondary Containment Systems

There isn’t a one-size-fits-all approach when it comes to secondary containment systems. The right setup depends on what’s being stored, how it’s being used, and how much of it there is. I put together this comparison based on the most common types of secondary containment I’ve come across in facilities, job sites, and reports.

OSHA Secondary Containment Requirements

OSHA secondary containment requirements are scattered across several standards, each tied to the type of hazard or material involved. There’s no single rule that covers every scenario, but the expectation is clear: if a substance can harm workers or ignite, it needs to be controlled. Containment is part of that control.

29 CFR 1910.106 – Flammable Liquids

This regulation directly addresses the requirements for storing and handling flammable and combustible liquids in the workplace. These regulations aim to protect workers by ensuring that flammable substances, such as fuels, solvents, alcohols, and even oily rags, are safely stored and handled.

Key Requirements:

• 1910.106(d)(4)(i): For inside storage rooms, openings to other rooms or buildings must be provided with noncombustible liquid-tight raised sills or ramps at least 4 inches in height, or the floor in the storage area shall be at least 4 inches below the surrounding floor. This provides passive spill control.
• 1910.106(b)(2)(vii): The area surrounding a tank or group of tanks shall be provided with drainage or shall be diked to prevent accidental discharge of liquid from endangering adjoining property or reaching waterways. This applies to aboveground tanks regardless of size.
• 1910.106(e)(2)(iii): Areas in which flammable liquids are transferred from one tank or container to another container shall be separated from other operations and drainage or other means shall be provided to control spills.

While not all sections use the term “secondary containment,” the function—catching and isolating a spill—is clearly required. A containment berm, spill pallet, or double-walled tank often meets these expectations depending on size and layout.

29 CFR 1910.120 – HAZWOPER

This standard applies to facilities involved in hazardous waste treatment, cleanup, or emergency response. Containment is central to both the prevention and mitigation strategies OSHA requires here.

Key Requirements:

• Employers must develop a written safety and health program, including procedures for hazardous material handling, storage, and spill control (1910.120(b)).
• Appendix C (non-mandatory guidance) emphasizes traditional containment methods such as diking, sorbent booms, and portable containment units. It also encourages employers to evaluate new containment technologies.
• Containment of hazardous materials during emergency response is expected under site control procedures (1910.120(d)).

Even when not spelled out in mandatory language, the control of leaks through secondary systems is integral to the intent and application of HAZWOPER.

29 CFR 1910.1450 – Occupational Exposure to Hazardous Chemicals in Laboratories

This standard covers laboratory operations involving hazardous chemicals and requires employers to implement a written Chemical Hygiene Plan.

Key Expectations:

• While the regulation doesn’t list specific containment equipment, it mandates the use of engineering controls to minimize employee exposure to hazardous chemicals (1910.1450(e)(3)(ii)).
• In practice, OSHA expects containment trays, spill guards, vented cabinets, and secondary containers for storing reactive, volatile, or corrosive materials.
• Section (h)(1) requires facilities to maintain fume hoods and other protective devices in working order, reinforcing that physical controls are part of spill prevention.

Labs may store smaller quantities, but containment failures can have serious consequences. OSHA’s expectation is that hazards are isolated and exposure is minimized.

General Duty Clause – Section 5(a)(1)

The Occupational Safety and Health Administration (OSHA) uses this clause to cite hazards that are not addressed by specific standards. If a chemical presents a risk of exposure or harm, and a reasonable employer would use secondary containment to prevent it, failing to do so can result in a citation.

How It Applies:

• If a facility stores chemicals in quantities below formal thresholds but still presents a risk (e.g., toxic pesticides, corrosives near drains), containment may still be required.
• OSHA looks at industry-recognized practices. If similar operations use spill containment systems, failing to do so may be treated as negligence.

This clause is used when the risk is real, the solution is reasonable, and the harm is preventable.

Compliance Inspections, Violations, and Penalties

Containment violations are regularly cited during OSHA inspections. Even without a spill, a facility can be penalized if it lacks systems to prevent one.

Common Violations:

• Storing bulk storage containers without berms, curbing, or other secondary containment measures in place.
• Using plastic spill pallets incompatible with the stored material (e.g., strong acids that degrade the pallet).
• Lack of maintenance—containment units that are cracked, sagging, or filled with rainwater.
• Inadequate employee training on spill procedures, even when containment systems are present.

Penalty Overview:

• First-time violations can still lead to significant fines if the risk is deemed serious.
• Repeat or willful violations tied to missing secondary containment, often lead to sharply increased penalties.
• OSHA may issue combined citations under multiple standards if containment failures endanger both workers and the environment.

Some time ago, I came across an OSHA enforcement case involving a hospital facility. Inspectors found incompatible laundry chemicals—a peroxide-based oxidizer and a caustic detergent—stored side by side on shelves and floors without any secondary containment measures. OSHA flagged this as a significant hazard, noting it could easily lead to dangerous chemical reactions.

OSHA cited the facility under the General Duty Clause, initially proposing a fine of around $14,000. Although the penalty was later reduced after corrective actions were taken, it highlighted how strictly OSHA enforces proper chemical storage and containment practices. Cases like this underscore the importance of chemical compatibility and secondary containment—not just in heavy industrial sites, but in workplaces of all types.

EPA Secondary Containment Requirements

While OSHA focuses on protecting workers, the EPA’s role focuses on protecting the environment, particularly water sources. EPA secondary containment regulations are designed to prevent the release of oil, hazardous waste, and other harmful substances into soil, groundwater, or surface water. Most of these requirements are outlined in the SPCC rule (40 CFR Part 112) and various containment mandates under RCRA regulations (40 CFR Parts 264 and 265) for hazardous waste tanks and storage areas.

What makes EPA regulations unique is that they apply based on environmental risk, not industry type. Whether it’s an oil tank on a farm or a hazardous waste unit at a treatment facility, the expectation is the same: leaks or spills must be contained before they escape the site.

40 CFR Part 112 – Spill Prevention, Control, and Countermeasure (SPCC)

This rule applies to facilities that store oil above certain thresholds and could potentially spill into navigable waters or shorelines. If a facility has more than 1,320 gallons of oil in aboveground containers or 42,000 gallons in underground tanks (not regulated as underground storage tanks under 40 CFR Part 280), it likely falls under SPCC.

Facilities under SPCC must have a written plan that includes both secondary containment and containment for transfer areas. The containment system must hold the volume of the largest single container plus enough extra capacity for precipitation, and it must be constructed from materials that are impermeable to oil. Common setups include containment berms, concrete dikes, and double-walled tanks.

40 CFR 264.193 – Hazardous Waste Tank Systems

Part of the Resource Conservation and Recovery Act (RCRA), this regulation applies to tank systems that store hazardous waste. It requires secondary containment capable of detecting and collecting any leaks, spills, or overflows.

The containment must be large enough to hold 100% of the largest tank’s contents and must keep out external water (run-on) from entering the system. Materials must be chemically compatible with the waste stored, and leak detection must be integrated. This rule is typically enforced at treatment, storage, and disposal facilities (TSDFs).

40 CFR 267.195 – Tank Systems 

This regulation outlines the secondary containment requirements for tank systems at facilities operating under a standardized permit. Key requirements include:

• Design and Operation: Secondary containment systems must be designed, installed, and operated to prevent any migration of wastes or accumulated liquid to the soil, groundwater, or surface water during the use of the tank system.
• Leak Detection: The system must be capable of detecting and collecting releases and accumulated liquids until they are removed.
• Construction Materials: Containment systems must be constructed of or lined with materials compatible with the waste and have sufficient strength and thickness to prevent failure due to various factors, including pressure gradients and climatic conditions.
• Foundation Requirements: The system must be placed on a foundation capable of providing support and preventing failure due to settlement or uplift.
• Drainage and Removal of Liquids: The design must allow for the drainage and removal of liquids resulting from leaks, spills, or precipitation. Spilled or leaked waste and accumulated precipitation must be removed from the containment system within 24 hours, or as promptly as possible if removal within 24 hours is infeasible, to prevent harm to human health and the environment.

These measures ensure that any potential leaks or spills from tank systems are promptly detected and contained, minimizing environmental contamination.

40 CFR Part 280 – Underground Storage Tank (UST) Regulations

The EPA's UST regulations establish technical standards to prevent, detect, and respond to releases from UST systems containing petroleum or hazardous substances. The regulations have been updated to enhance environmental protection, with significant revisions effective April 11, 2016.

Key Requirements

• Secondary Containment for New and Replaced Systems: Tanks and piping installed or replaced after April 11, 2016, must be secondarily contained and use interstitial monitoring. The secondary containment must:
• Contain regulated substances leaked from the primary containment until they are detected and removed.
• Prevent the release of regulated substances to the environment at any time during the operational life of the UST system. 

Piping Requirements:

• Pressurized Piping: Must be monitored for releases at least every 30 days and be equipped with an automatic line leak detector.
• Suction Piping: Must be monitored for releases at least every 30 days unless it meets specific design criteria that exempt it from release detection requirements.

Compatibility:

UST systems must be constructed or lined with materials that are compatible with the substance stored to prevent corrosion and structural failure.

These regulations aim to prevent environmental contamination by ensuring that UST systems are properly designed, constructed, and monitored throughout their operational life.

Consequences of Noncompliance

The EPA can issue significant penalties for failures related to secondary containment, even when no spill has occurred. Civil fines under the Clean Water Act and RCRA can exceed $60,000 per violation per day, especially when violations are ongoing or tied to environmental harm.

Violations typically fall into these categories:

• SPCC-related: No plan in place, incomplete documentation, or containment systems that can't hold the required volume.
• Hazardous waste tanks (RCRA 264/267): Damaged or missing secondary containment, poor maintenance, or lack of leak detection.
• UST systems (40 CFR 280): Improper installation, failure to upgrade to double-walled tanks or sumps, and missing release detection.

Other common triggers for enforcement:

• Failure to remove accumulated spills or rainwater from containment areas.
• Use of incompatible materials in containment systems.
• Lack of weekly inspections or system integrity checks.
• Inadequate training or absence of site-specific procedures for managing hazmat.

One case I found involved multiple hazardous waste facilities where secondary containment systems for tanks weren’t properly maintained. The EPA and DOJ issued a civil penalty of $1,162,500, and the operator was required to upgrade systems across several states. It stood out to me because the violations weren’t hidden—most were conditions that could’ve been caught with basic inspections.

Containment issues like these are treated as avoidable. When the systems are ignored or allowed to break down, enforcement usually follows.

When Is Secondary Containment Required?

Secondary containment isn’t always triggered by law, but that doesn’t mean it shouldn’t be used. Plenty of facilities choose to install containment around storage areas, tanks, or transfer points simply to reduce risk or meet internal standards. Whether or not it’s required, it remains one of the most effective ways to minimize damage from leaks or spills.

That said, there are specific situations where secondary containment requirements are enforceable under OSHA and EPA secondary containment regulations.

When OSHA Secondary Containment Is Required

• Flammable Liquids Storage (29 CFR 1910.106): Facilities storing flammable liquids must have containment systems to prevent the spread of spills. For instance, storage areas should be graded to divert spills away from buildings or surrounded by curbs of at least 6 inches high.
• Construction Sites (29 CFR 1926.152): No more than 25 gallons of flammable liquids shall be stored in a room outside of an approved storage cabinet.

When EPA Secondary Containment Is Required

• SPCC Rule (40 CFR 112): Facilities with aboveground oil storage exceeding 1,320 gallons, and a reasonable expectation of discharge into navigable waters must implement secondary containment measures.
• Hazardous Waste Tank Systems (40 CFR 264.193): Owners and operators of new tank systems must ensure secondary containment that includes an external liner, a vault, a double-walled tank, or an equivalent device approved in writing by the Regional Administrator.
• Underground Storage Tanks (USTs) (40 CFR 280): UST systems must have secondary containment capable of containing regulated substances that leak from the primary containment until they are detected and removed, preventing environmental release.

Are You Overlooking Smaller Risks?

One of the most common misconceptions I’ve run into is that secondary containment requirements only matter when you’re dealing with massive tanks or large-scale chemical transfers. But in reality, it doesn’t take hundreds of gallons to cause serious harm. Small spills—especially in overlooked areas—can lead to injuries, contamination, or expensive shutdowns if they’re not controlled quickly.

A single leaking container, an overfilled drum, or a disconnected hose at a maintenance sink can all cause slips, skin contact, or chemical reactions if nothing’s in place to catch and contain the release. I’ve seen people overlook these small sources just because they didn’t think the volume “qualified” for secondary containment requirements.

I read a case where a worker at a water treatment facility was responding to what started as a small leak during an acid transfer. A coworker cut a zip tie and opened the cam locks without depressurizing the line, which led to a sudden discharge of fluorosilicic acid under pressure. The worker nearby wasn’t wearing respiratory protection and had to be hospitalized for several days after inhaling the vapors.

The system wasn’t built to contain a failure like that, even though the transfer involved a hazardous substance. The volume released came fast, but the root problem started with one weak connection and no backup containment.

It’s easy to overlook these smaller risks, especially in areas where things “usually don’t leak.” But that’s exactly where secondary containment makes the most difference—not just around tanks, but anywhere something dangerous is being moved, handled, or stored.

FAQs

What is secondary containment vs. primary containment?

Primary containment is the first layer that holds a hazardous material—like a tank, drum, or pipe. Secondary containment is a backup system (like a berm, sump, or double-walled tank) that captures the material if the primary system fails.

What is sized secondary containment?

Sized secondary containment refers to systems that are built to hold a specific volume—typically 100% of the largest container in the area, plus additional capacity for rainfall if outdoors. This is a standard requirement under EPA’s SPCC and RCRA regulations.

When must you use secondary containment for the transport of hazardous chemicals on-site?

Secondary containment is required when transferring hazardous chemicals in a way that could expose workers or the environment to a spill. If materials are moved by hose, pipe, or open containers—especially across paved or drain-connected surfaces—OSHA and EPA regulations may apply, depending on the volume and substance.

What waste needs secondary containment?

Hazardous waste stored in tanks or containers generally requires secondary containment under 40 CFR 264 or 267, especially if it contains free liquids. Waste oils, solvents, and corrosive substances are common examples that must be stored with containment systems in place.

What is primary and secondary containment for biohazards?

In lab and medical settings, primary containment for biohazards includes tools like biosafety cabinets or sealed tubes. Secondary containment refers to room-level barriers or sealed transport containers that protect against a release if the primary system is breached, especially in BSL-2 and BSL-3 environments.

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