Channing McCorriston, The Container Guy, will show you how to install Secondary Containment Pans in two different 20’ Open Side Shipping Containers for the purpose of Hazardous Material (HAZMAT) Storage.
This step-by-step container modification will take you along as we install containment pans and vents in two 20ft one-time use (like new) sea containers. We will then repaint and install the vinyl decal to complete the mod.
Purchase Container Modification World Products
Specialty Hazardous Material Storage Containers: Design, Safety, and Compliance
Storing hazardous materials inside shipping containers requires far more than simply adding shelves and locks. In this detailed walkthrough, Channing McCorriston, The Container Guy, explains how specialty 20-foot containers are engineered specifically for hazmat storage, with safety, containment, and compliance built into every component.
These units are not standard containers modified after delivery. They are purpose-built specialty containers designed to meet the strict demands of chemical storage across industrial environments.
Two Types of Specialty Containers
Two configurations are commonly used for hazardous material storage:
Four Side Door Container
This version features four individual side doors separated by structural posts. Each door opening measures approximately 47.5 inches wide, making it suitable for standard pallets up to 42 inches wide.
This design allows organized compartment access while maintaining structural strength.
Full Open Side Container
This configuration allows the entire side of the container to open using accordion-style hinged doors. With up to 18 feet of vertical lift clearance, it provides easier loading and unloading access for larger equipment and bulk storage.
Secondary Containment: The Core Safety Feature
At the heart of any hazmat container is the secondary containment system.
These containers feature 6-inch deep galvalume containment pans welded inside the structure. Each pan section measures approximately 76 inches long and connects using bulkhead fittings.
Total containment capacity is roughly 2,000 liters, or about 530 US gallons.
Regulatory guidelines typically require:
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110 percent containment of the largest drum stored, or
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25 percent of the total stored liquid volume
The pans are compartmentalized to prevent spill migration and feature smooth rounded edges for worker safety.
Bar grating sits above the pans and is removable for easy spill cleanup. Specialized clips recess fasteners below the grating surface to prevent pallet damage during loading.
After fabrication, welds are zinc-sprayed to reduce corrosion risk.
Ventilation Designed for Chemical Safety
Ventilation is critical in hazardous material storage.
Each container includes eight passive vents: four positioned high and four positioned low on opposite sides. This configuration promotes cross-flow ventilation and accommodates both lighter-than-air and heavier-than-air vapors.
Unlike small pressure-relief vents, these systems are designed for real air exchange.
Climate Control Options
Depending on the chemicals stored, containers can be configured with:
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Insulation
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Explosion-proof electrical systems
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Heating systems
For oils and lubricants that do not require freeze protection, non-insulated containers with passive ventilation may be sufficient.
The correct configuration depends entirely on the chemical properties outlined in the Safety Data Sheets provided by the customer.
Material and Coating Considerations
Material selection must align with chemical compatibility.
Options include:
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Galvanized steel
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Galvalume
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Coated mild steel
Immersion and containment compatibility must be reviewed using SDS documentation before final material selection.
Customers are responsible for specifying:
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The chemicals being stored
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Drum size and total volume
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Ventilation requirements
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Heating needs
Security and Door Safety
Security is a major consideration for hazmat storage.
Factory-installed lock boxes are preferred over aftermarket bolt-on systems. A block-style lock with an 80 mm shackle is recommended to prevent cutting or tampering.
Door lock rods are fitted with ropes to prevent doors from swinging open in windy conditions, improving both safety and operational control.
Retrofitting Existing Containers
For customers who already own containers, secondary containment pans and bar grating can be shipped separately for on-site installation.
This modular approach allows existing containers to be upgraded without purchasing a fully new specialty unit.
Quality and Final Details
After vent installation and fabrication, containers are painted to customer specifications.
Containment capacity labeling is recommended to ensure regulatory clarity.
Each finished unit reflects careful attention to safety, structural integrity, and chemical compatibility.
Key Takeaways
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Hazmat containers must be customized based on chemical type and volume
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Secondary containment is essential for spill control and compliance
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Ventilation must be engineered for vapor behavior
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Material compatibility depends on SDS documentation
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Security and door safety are critical operational considerations
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Modular systems allow retrofitting existing containers
Final Thoughts
Specialty hazardous material storage containers are engineered systems, not simple storage boxes.
By combining secondary containment, proper ventilation, chemical-compatible materials, and strong security features, these modified containers provide a safe and compliant solution for industrial chemical storage.