Are Bunded Oil Tanks at Risk of Exploding? What You Need to Know

Oil storage safety is a serious concern, and many people ask whether bunded oil tanks can explode. With the right design, installation, and upkeep, the risk is very low. In this post, we’ll explain how bunded tanks work, what conditions could potentially lead to serious failure, and what you can do to make sure your tank remains safe and reliable.

Understanding Bunded Oil Tanks & Their Built-In Protections

A bunded oil tank features an inner vessel that holds the oil, surrounded by a secondary containment vessel (the bund). This dual-structure design helps:

• Prevent leaks and capture oil if there’s a breach in the inner tank.

• Limit vapour accumulation by housing ancillary equipment properly.

• Incorporate safety features like overfill alarms, venting systems, and pressure relief fittings.

UK regulations also require that such tanks follow standards on design, containment, and positioning. For example, the UK government outlines specific rules in its guide on storing oil at your home or business.

What Could Cause a Serious Incident (Including Explosion)

Though explosions are rare, certain failings can compound risk:

• Poor maintenance: rust, corrosion, worn or damaged valves, and degraded seals can let vapours escape or compromise the tank.

• Overheating or exposure: if the tank or its fittings are exposed to intense heat (e.g. from nearby fire), internal pressure can build up.

• Vapour ignition: any spark or ignition source near escaped vapours is dangerous. Ensuring proper ventilation and safe equipment placement is key.

• Non-compliant installations or modifications: altering safety components or not following regulation rules greatly increases risk.

The Health and Safety Executive provides detailed guidance in The storage of flammable liquids in tanks (HSG176), which explains how tanks should be constructed and maintained to prevent incidents.

Regulatory & Best Practice Requirements in the UK

Regulations define the safety baseline:

• The Environment Agency, via gov.uk oil storage regulations, requires bunded oil tanks to include secondary containment, siting clearances, and compliant fittings.

• For technical standards on bund capacity and spill containment, see the HSE’s Containment measures for bulk storage of liquids.

Manufacturers and responsible owners should also ensure that valves, vents, gauges, and overfill devices are installed and serviced according to OFTEC standards.

How Homeowners & Businesses Can Maximise Safety

Here are best practices you can follow:

• Hire certified professionals for installation and regular inspection.

• Keep the area around the tank clear of debris, flammable materials, and ignition sources.

• Inspect your tank and fittings monthly; schedule annual servicing.

• Follow manufacturer manuals and comply with UK regulations.

Reassurance: Explosion Risks Are Extremely Low

With all of the safety features in place—dual containment, pressure relief valves, overfill protection, proper siting, and regular inspections—bunded tanks are built to be extremely safe. Incidents are rare and almost always linked to neglect, tampering, or non-compliance.

Internal Resources at OTP Energy

• Learn more in our guide: How Bunded Oil Tanks Function & Their Benefits.

Final Thoughts

So, can a bunded oil tank explode? The short answer: only in exceptional circumstances. With proper design, installation, and maintenance, they are a safe and reliable option for heating oil storage in both domestic and commercial settings.

By following these tips and partnering with a trusted supplier like OTP Energy, you can ensure you’re getting the best possible price for your heating oil needs.