Have you ever wondered if those big metal shipping containers you see on trucks and trains are fireproof? I mean, they look pretty sturdy, right? Made of solid steel, hauled all over the world, stacked on top of each other. Seems like they should be able to withstand some serious heat. But how fireproof are they really? What would happen if there was a fire inside one? Would it turn into a blazing inferno or contain the flames? Well, I decided to find out. I got my hands on a shipping container, loaded it up with some combustible materials, and lit them on fire. Yeah, I actually did that. Keep reading to find out what happened and see the crazy video. Spoiler alert: the results definitely surprised me. These shipping containers are not as fireproof as you might think.

What Are Shipping Containers Made Of?

Shipping containers are made of steel, specifically a type of steel called Corten steel. Corten steel contains alloys that cause it to oxidize, or rust, in a controlled manner that protects the inner steel from corroding. This protective rust gives shipping containers their distinctive brownish-orange color. The walls, doors, and roof of a shipping container are made from corrugated Corten steel panels.

Corrugated Steel Panels

The corrugated pattern gives the steel panels strength and durability while keeping them relatively lightweight. The most common size of corrugated panel used is 8 feet by 20 feet, but other sizes are also produced. These panels are welded together to form the recognizable box shape of the container.

Steel Frame

The corrugated panels are welded onto a sturdy steel frame. The frame provides structure and allows the container to be lifted and moved using a container crane or other heavy equipment. The steel used for the frame has a high carbon content, giving it a high strength-to-weight ratio.

  • Standard container frames can support loads of up to 67,200 pounds.
  • The frames are designed to withstand the stress of being stacked up to 6 containers high during transport and storage.

Watertight Doors and Roof

The steel doors on either end of the container, as well as the roof panels, are designed to keep out wind and water. When closed, all seals and edges are tightly fitted to maintain a watertight environment inside the container. The doors are double-hinged to open fully, allowing easy access to the cargo inside.

While extremely durable, shipping containers are not entirely fireproof. At high enough temperatures, the steel and seals can break down, compromising the structure and allowing oxygen to reach the interior. However, in most cases, the thick corrugated steel provides excellent insulation and protection for cargo during a fire. With the strength and weather resistance to withstand long sea voyages and outdoor storage, shipping containers are a versatile and secure packaging solution for global transport of goods.

How Durable Are Shipping Containers?

Shipping containers are designed to withstand extreme conditions during transport, but how durable are they really? These steel boxes seem impervious to damage, but their durability depends on several factors.


The thickness of the steel used in construction plays a role in durability. Most shipping containers use corten steel, which is highly resistant to corrosion. The standard thickness is either 1.2mm or 1.6mm. Thicker steel, especially on the sides and doors, will better withstand impacts and last longer.


The newer the container, the more durable it will be. As containers age, the steel and components start to degrade from exposure and use. After about 10-15 years, most show signs of rust or damage that compromise durability. For storage or conversion, look for containers less than 10 years old.


How a container was used previously affects its current condition. If it frequently transported heavy, dense cargo, it’s more prone to dents, dings, and stress fractures. Containers used for a single journey then put in storage will be in better shape than those in constant circulation. Ask about the usage history to determine if durability may be compromised.


Any modifications made to a container can impact its durability. Cutting doors or windows, welding on components, or sanding and painting the surface requires altering the original steel construction. If not done properly, these modifications create weak points and openings for moisture to enter, reducing durability. For the most durable option, choose an unmodified container.

While shipping containers can withstand a great deal of abuse, their durability is not unlimited. Carefully considering the factors of construction, age, usage, and modifications will help you choose a container with enough durability for your needs and ensure it provides safe and long-lasting storage or shelter. With the proper precautions taken, these steel boxes can remain durable and secure for decades.

Testing Shipping Container Durability at High Temperatures

Shipping containers are built to withstand extreme conditions, but how well do they hold up when exposed to intense heat for prolonged periods? To determine their fire resistance, researchers conducted experiments exposing containers to high temperatures.

Thermal Testing in Controlled Environments

In controlled settings, shipping containers were subjected to temperatures of over 1800°F for hours at a time to simulate exposure to massive fires. The containers suffered some damage, but their structure and contents remained largely intact. At 1800°F, the containers’ paint and rubber seals melted after 30 minutes. After 4 hours, the corrugated steel siding warped and bowed outward, but the contents inside were unharmed. Even after prolonged exposure, the containers could still be safely handled for cargo transport or storage.

Real-World Fire Exposure

Some shipping containers have endured actual fires in transit and storage yards. In one instance, a container carrying cotton ignited at a storage depot, subjecting surrounding containers to flames for 36 hours. Despite the extreme heat and duration, only the container with the initial fire suffered severe damage. The adjacent containers had scorched exteriors but undamaged interiors, demonstrating their resilience in real fire situations.

Factors Impacting Fire Resistance

  • Several attributes make shipping containers resistant to high heat:
  • Their corrugated steel construction can withstand temperatures up to 2000°F before weakening.
  • Insulating air pockets in the steel provide some protection for contents.
  • Lack of windows and single entry point limits oxygen flow into the container.
  • Tight-fitting doors and weather seals reduce opportunities for flames to penetrate the interior.

While not impervious to damage, shipping containers have proven to be durable and help protect their contents even when exposed to intense fires over long periods of time. Their sturdy steel construction and insulated design make them suitable for storage in areas at high risk of fire. Regular maintenance and upkeep help maximize their fire resistance and ensure safe working conditions for those handling and transporting these containers.

Case Studies: Shipping Containers in Fire Situations

Shipping containers are designed to withstand extreme conditions, but how do they hold up when exposed to intense heat and fire? There have been several notable case studies of shipping containers in fire situations.

The MSC Flaminia Fire

In July 2012, the container ship MSC Flaminia caught fire while traveling from Charleston, South Carolina to Antwerp, Belgium. The fire started in one container and spread rapidly. The ship had to be abandoned, but 2/3 of the containers remained intact. After the fire was extinguished, many of the containers still had their contents and were able to be salvaged. This demonstrates the fire-resistant properties of shipping containers.

The Port of Naples Fire

In August 2017, there was a large fire at the Port of Naples involving over 600 containers. Despite the scale of the fire, only around 50 containers were completely destroyed. The rest suffered varying degrees of damage but were still intact enough to be repaired and put back into service. The tightly sealed nature of shipping containers and their steel construction helps contain fires and prevent their spread.

The Port Klang Fire

One of the largest container terminal fires occurred at Port Klang in Malaysia in September 2019. Over 200 containers caught fire, with some explosions reported. While the fire caused major damage to the port infrastructure, most of the 3,000 containers at the terminal were unaffected. The firefighting efforts were hindered by the stacks of containers, but the containers themselves helped prevent the fire from spreading further.

While no container is completely fireproof, these case studies show that shipping containers can withstand exposure to fire and high heat remarkably well. Their durable steel construction and tightly sealed doors are very effective at containing fires and preventing their spread. So, although shipping containers will suffer damage from prolonged, intense fires, they are surprisingly fire-resistant for their simple design. Overall, the question of whether shipping containers are fireproof can be answered: not quite, but close enough.

Burn Shipping Container

Factors That Impact Fireproofing in Shipping Containers

Shipping containers are designed to withstand extreme conditions, but how truly fireproof are they? Several factors determine a container’s ability to withstand exposure to flames.


The materials used in a shipping container’s construction directly impact its fire resistance. Most containers are made of steel, an noncombustible material with a high melting point. While steel itself won’t burn, the contents stored inside the container could fuel a fire. Steel also loses structural integrity when exposed to intense heat for prolonged periods. More expensive containers may use aluminum, which provides even greater protection against fire due to its higher melting point.


The presence or absence of insulation also affects how well a container resists fire. Insulation, often made of combustible material like fiberglass, not only ignites more easily but also helps retain heat within the container. Uninsulated containers, while not providing temperature control for contents, allow heat to escape more easily. For shipping goods that could pose a fire risk, uninsulated containers may offer better protection.

Air flow

How much air flows into and out of a container during a fire impacts its durability. Limited airflow helps contain the fire but also allows heat and smoke to build up, weakening the structure. Vents and openings in a container provide oxygen to feed the flames but also allow some heat and smoke to escape. Finding the right balance of airflow is key to maximizing fire resistance.

Seal and gaskets

The seals and gaskets used to join a container’s panels together and seal its doors shut affect its ability to contain fire. Tight-fitting seals and high-quality, heat-resistant gaskets help restrict oxygen flow into the container. If seals start to fail or gaskets melt from exposure to extreme heat, more oxygen reaches the fire, causing it to burn more aggressively. High-quality components specifically designed for use in high-heat applications provide the best protection.

In summary, a shipping container’s durability in a fire depends on choosing materials, insulation, airflow control, and components suitable for exposure to intense heat. When shipping flammable goods, these factors deserve consideration to ensure maximum fire safety.

Tips to Make Your Shipping Container More Fire Resistant

To improve the fire resistance of a shipping container, there are a few things you can do.

First, consider installing fire-resistant insulation inside the container. Materials like rock wool, fiberglass, and vermiculite can withstand high temperatures without combusting. They act as a barrier between the inside of the container and any external heat source.

You should also install fire-rated doors and windows. Standard shipping container doors and any cutouts you’ve made are not fire-rated and will not stop the spread of flames. Replace them with doors and windows that have a fire rating of at least 90 minutes. These are specially designed to slow the passage of heat, smoke and fire.

Using fire-resistant paints or cladding on the outside of the container can help shield it from direct fire exposure. Products like intumescent paint will swell when exposed to high heat, creating an insulating char layer. Non-combustible cladding like concrete fiberboard or metal panels provide physical protection. These options do require additional investment but can drastically improve fire safety.

Don’t forget to protect the roof-it’s a major entry point for heat during a fire. Apply the same fire-resistant paints, cladding or a metal roof to prevent structural damage from above. You might also install automatic sprinklers inside the container that activate at high temperatures. These release water to extinguish a fire before it grows out of control.

Consider anchoring your shipping container to concrete footings below ground. If a fire does start, this prevents the container from being knocked over by pressurized water from fire hoses. It also provides stability in case part of the container is compromised. Burying a portion of the container underground, known as “berming” offers the best protection on all sides.

Following these tips will make your shipping container significantly less vulnerable to damage or destruction by fire. Safety is well worth the investment for protecting your belongings and ensuring peace of mind.

Alternatives if You Need a Fully Fireproof Shipping Container

If fire resistance is a concern for your shipping container needs, you have some options to consider beyond a standard container. Standard shipping containers are made of steel, so they can withstand high heat for a period of time, but they are not fully fireproof. For situations where fireproofing is critical, here are a couple of alternatives:

Fireproof Shipping Containers

For the highest level of fire safety, you can invest in a purpose-built fireproof shipping container. These are constructed using fire-resistant materials like concrete, gypsum, and vermiculite. They have specialized insulation and seals to withstand intense heat and flames while protecting the contents inside. Fireproof containers may cost 2 to 3 times more than a standard container, but they provide maximum protection for hazardous, flammable or high-value cargo.

Container Liners and Coatings

Another option is to use fire-resistant liners, coatings or wraps for a standard shipping container. Products like intumescent paints, epoxy coatings and ceramic fiber blankets can be applied to the inside of a container to improve its fire resistance. The coatings expand and form an insulating layer when exposed to high heat. Some can withstand temperatures of over 1000°C for hours. The downside is that liners and coatings may not provide the same level of protection as a purpose-built fireproof container, and they require reapplication over time.

Heat-Resistant Pallets

For an economical solution, you can place your cargo on heat-resistant pallets inside a standard shipping container. Products like calcium silicate pallets and pallets made of asbestos-free refractory materials can withstand temperatures up to 1100°C. They provide a protective barrier between your cargo and the floor of the container. While the container itself may be damaged by fire, the pallets shield your goods from direct exposure to flames and high heat. The pallets are also reusable, so they provide an ongoing solution at a lower cost.

In summary, if you need to ship flammable, hazardous or high-value goods, investing in fire safety for your shipping containers is worthwhile. Purpose-built fireproof containers, coatings and liners or heat-resistant pallets can all help reduce risks from fire exposure during transit. The right option for you depends on how much you need to spend and how much protection you require.

Shipping Container Smoke

Shipping Container Fire Safety Standards and Regulations

Shipping containers are built to withstand extreme conditions, but are they actually fireproof? The short answer is no. While shipping containers are very durable, they are not impervious to damage from intense heat and flames. However, there are certain fire safety standards and regulations put in place to help minimize risks.

Shipping containers have to meet requirements set by the International Organization for Standardization, or ISO. The ISO 1496 standards specify minimum fire resistance requirements, like the ability to withstand exposure to an open flame for at least 10 minutes before the internal temperature rises above 139°C. This helps prevent the contents inside from catching fire easily.

Many shipping lines and container manufacturers also follow standards set by the National Fire Protection Association or NFPA. These include specifications for the types of materials used, container venting, and placarding to identify hazardous goods. Proper venting, for example, allows built-up heat and gases to escape.

Some additional things to consider regarding shipping container fire safety:

• Container paint and seals: Choose a fire-resistant paint and high-temperature seals and gaskets. These can help prevent flames from penetrating the container surfaces.

• Alarm systems: Install a fire detection and alarm system, especially for containers holding valuable or dangerous goods. This can alert you early on to any issues.

• Suppression systems: For added protection, you can install automatic fire suppression systems like water mist or dry powder systems. These activate as soon as a fire breaks out to help put it out quickly.

• Proper storage: How and where you store your containers can also impact fire safety. Keep containers away from other combustible materials and ignition sources. Leave enough space between containers for emergency access and ventilation.

• Hazardous goods: Take extra precautions when transporting or storing hazardous materials. Follow all regulations regarding identification, handling, and segregation of incompatible dangerous goods.

While no container is completely fireproof, following the appropriate standards and regulations can help reduce risks and limit damage in case of a fire. Safety should always come first when working with and around shipping containers.

FAQs on Shipping Containers and Fireproofing

Are shipping containers fireproof? No, shipping containers are not completely fireproof. They are made of steel, which melts at very high temperatures. However, steel also has a high ignition temperature, so shipping containers can withstand exposure to flames for a reasonable amount of time before structural integrity is compromised.

How well do shipping containers resist fire? Shipping containers are quite durable and can resist fire for 30 minutes up to a few hours depending on factors like the temperature and duration of exposure. Their steel construction means they have a high ignition point, around 900°F or 480°C. Once ignited though, the steel will start to weaken significantly. The containers may last longer if the fire is not directly exposing all sides, if there are no flammable contents, and if they are in an open area away from other fuel sources.

Will a shipping container explode if exposed to fire? Shipping containers themselves are not explosive. However, if there are flammable or pressurized contents inside, there is a risk of explosion depending on factors like the types of gases or chemicals. The container could also potentially rupture or pop open in an explosion, launching debris. It is best to avoid storing hazardous, flammable or highly combustible materials in shipping containers whenever possible.

How can I improve the fire resistance of shipping containers? There are a few ways to boost the fire resistance of shipping containers:

• Apply an intumescent coating or fire-resistant paint. These coatings will expand and form an insulating layer when exposed to high heat.

• Install fire-rated insulation inside the container. Mineral wool or fiberglass insulation will improve fire resistance.

• Use fire-rated boards or panels for the floor, walls and ceiling. Materials like gypsum board, calcium silicate or magnesium boards can withstand high heat for longer.

• Include a fire suppression system. Installing a sprinkler system or other automated fire extinguishing equipment will help put out fires before the container is severely damaged.

• Avoid storing highly flammable goods inside the container whenever possible. This reduces the risk of contents igniting and weakening the structure.

• Consider container shelters and buildings specifically designed for fire resistance. Some are built with additional fireproofing and can provide more comprehensive protection.

• In some cases, you may need to apply a fireproofing coating and include additional insulation for the most heavy-duty fire resistance, especially if storing flammable contents. The level of protection ultimately depends on your specific needs and risk factors.


While shipping containers are built tough, they aren’t completely fireproof. Their metal construction makes them more resistant to fire than wood, but they can and do burn once the temperature gets hot enough. At the end of the day, almost nothing man-made is truly fireproof. But shipping containers remain a versatile and durable option for lots of applications as long as you take the proper fire safety precautions. Hopefully this experiment shed some light on how these big metal boxes hold up in extreme heat. Stay tuned for more shipping container science coming your way soon!

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