Bung

What Is a Bung?

A bung is a closure device used to seal the opening of a drum, barrel, or tank that stores or transports liquids. While the term is often associated with 55-gallon drums (compared to the 42-gallon standard crude oil barrel), the bung itself is the stopper or plug, not the drum. It is inserted into the bunghole to prevent the contents from leaking, spilling, or being exposed to air.

Bungs are commonly used in industries that handle fuels, chemicals, food products, and waste materials, where maintaining a tight seal is essential for safety and compliance.

How a Bung Works

A bung fits securely into a threaded or press-fit opening on a drum or tank. Once installed, it creates a sealed closure that prevents fluid movement unless intentionally opened.

To function properly, a bung must:

• Withstand internal pressure from the liquid inside the container
• Remain stable during transport and handling
• Prevent leakage, vapor escape, or contamination

Because drums may experience movement, vibration, and pressure changes, bung adapters are typically made from rigid materials such as metal or high-grade plastic designed for industrial use.

Common Uses of Bungs in Industry

Bungs are used across a wide range of applications, including:

• Fuel and petroleum storage
• Chemical transport and containment
• Food and beverage processing (e.g., sauces, syrups, juices)
• Waste containment and recycling
• Industrial manufacturing and distribution

Their standardized design makes them a practical and widely accepted solution for liquid storage and transport.

Materials and Design Considerations

The material used for a bung depends on the contents of the drum and the operating environment. Common materials include:

• Steel or aluminum for high-pressure or chemical applications
• Plastic or polymer bungs for food-grade or non-corrosive liquids

A properly selected bung ensures compatibility with the stored substance and helps prevent degradation, leakage, or failure over time.

Reuse and Recycling of Bungs and Drums

Because 55-gallon drums are a standard industrial container, both drums and bungs are often reused or recycled, making them a cost-effective and environmentally responsible option.

Before reuse or recycling, several factors must be evaluated.

What Did the Drum Contain?

Determining the previous contents is critical. Drums that held non-hazardous materials, such as food products or washable liquids, are generally safe to repurpose. Drums that contained toxic or hazardous substances require specialized cleaning or disposal.

Is the Drum Clean?

If reuse is possible, the drum should be thoroughly cleaned. A common method is the triple-rinse technique, which helps remove residue and prepares the container for a different application.

Was the Drum Inspected?

After cleaning, inspect the drum and bung for:

• Dents or cracks
• Rust or corrosion
• Leaks or damaged threads

If the bung or drum can no longer provide an airtight seal, it should not be used for liquid storage. However, it may still be suitable for non-liquid uses such as storing solid materials.

Proper Disposal of Damaged Bungs

If a bung or drum is no longer usable, proper disposal is required. Many local recycling centers and environmental services departments accept drums that have not been used to store hazardous materials.

If hazardous substances were involved, disposal may need to be coordinated with a local hazardous waste authority or a certified drum recycling facility to ensure regulatory compliance.

Related Glossary Terms

• Drum
• Bonding
• Grounding
• Static Electricity
• Hazardous Materials