An ISO tank is a standardized, intermodal container designed specifically to transport and store liquid chemicals, gases, and other hazardous or non-hazardous substances in bulk. Built to ISO (International Organization for Standardization) specifications, these cylindrical stainless steel tanks are mounted within a rectangular frame that fits standard shipping dimensions, making them compatible with road, rail, and sea transport. The sections below answer the most common questions chemical shippers ask about ISO tank uses, capacity, safety, and when to choose them over alternative containers.
What types of chemicals are transported in ISO tanks?
ISO tanks are used to transport a wide range of liquid chemicals, including hazardous and non-hazardous substances. Common cargo includes industrial solvents, acids, alkalis, resins, foodstuffs, lubricants, and specialty chemicals. Their sealed, inert stainless steel construction makes them suitable for both aggressive chemicals and sensitive food-grade or pharmaceutical liquids.
The versatility of the ISO tank container comes from the ability to specify lining materials, heating coils, and pressure ratings to match the product being carried. Heated ISO tanks, for example, allow viscous substances such as resins or molasses to remain fluid during transit even in cold climates. Tanks rated for hazardous goods comply with ADR, IMDG, and RID regulations, covering dangerous goods by road, sea, and rail, respectively. This regulatory coverage means a single container type can legally carry everything from cleaning chemicals to specialty industrial fluids across international borders.
How does an ISO tank keep chemicals safe during transport?
An ISO tank keeps chemicals safe through a combination of robust construction, pressure management, and regulatory compliance. The inner vessel is typically made from food-grade or industrial-grade stainless steel, surrounded by insulation and a protective outer shell. Pressure relief valves, bottom discharge valves, and sealed manholes prevent leaks and contain vapours throughout the journey.
Safety in chemical transport depends on matching the container specification to the product. ISO tanks are fitted with safety accessories such as emergency shut-off systems, anti-surge baffles, and grounding points to prevent static discharge with flammable liquids. The standardized frame protects the inner vessel from impact during loading, stacking, and transit. Drivers and handlers working with hazardous cargo must hold ADR certification, and the tanks themselves undergo regular inspection and testing under international standards. Together, these layers of protection make the ISO tank one of the safest formats available for bulk chemical logistics.
What is the difference between an ISO tank and a chemical drum or IBC?
The key difference between an ISO tank, a chemical drum, and an intermediate bulk container (IBC) is capacity and reusability. An ISO tank holds between 14,000 and 26,000 litres as a single sealed unit, while a standard chemical drum holds around 200 litres and an IBC typically holds between 600 and 1,250 litres. ISO tanks are built for repeated, long-term use; drums and IBCs are often single-use or limited-cycle.
Beyond volume, each format serves a different logistical purpose:
- ISO tanks suit large bulk shipments moving internationally by sea, road, or rail. They eliminate the need to repackage product and reduce handling steps, lowering contamination risk.
- IBCs work well for mid-volume shipments where the buyer needs to decant product into smaller batches. They are palletized and fork-truck compatible, making warehouse handling straightforward.
- Drums remain practical for small quantities, samples, or products that need to be distributed to multiple end users in fixed-size units.
For chemical shippers moving consistent, high-volume product flows, the ISO tank delivers a lower cost per litre of product transported and significantly less packaging waste compared to drums or IBCs.
Can ISO tanks be used for storage as well as transport?
Yes, ISO tanks can be used for on-site storage as well as transport. Because they are self-contained, structurally robust, and already compliant with chemical containment regulations, they are frequently positioned at production sites, distribution terminals, and warehouses as temporary or semi-permanent storage vessels. This dual-use capability is one of the practical advantages of the ISO tank format.
Using an ISO tank for storage avoids the need to transfer product into a fixed tank, which reduces the risk of contamination and simplifies inventory management. Heated tanks maintain temperature-sensitive products during storage just as effectively as during transit. That said, long-term static storage in an ISO tank requires regular inspection to maintain certification, and some jurisdictions impose specific requirements on tanks used as fixed installations. Working with a specialist chemical logistics provider ensures that storage-in-transit arrangements meet all applicable safety and regulatory standards.
What are the size and capacity options for ISO tanks?
ISO tanks are available in several standard sizes, with the most common being the 20-foot equivalent unit (TEU). A standard 20-foot ISO tank container has an outer frame measuring approximately 6.1 metres in length and an inner vessel capacity ranging from 14,000 to 26,000 litres, depending on the product density and the tank’s pressure rating.
Capacity varies based on several design factors:
- Pressure rating: Higher-pressure tanks for gases or volatile liquids have thicker walls, which reduces internal volume.
- Insulation and heating: Tanks fitted with insulation jackets or heating coils have slightly reduced net capacity compared to uninsulated models.
- Product density: Regulations limit the fill weight as well as fill volume, so dense chemicals may not fill a tank to its geometric maximum.
For most bulk liquid chemicals, a single 20-foot ISO tank effectively replaces between 80 and 130 standard 200-litre drums, making it a highly efficient format for high-volume chemical transport.
When should a chemical shipper choose an ISO tank over other options?
A chemical shipper should choose an ISO tank when moving large volumes of liquid product internationally, when minimizing handling and repackaging is a priority, or when the chemical requires temperature control during transit. ISO tanks become the most cost-effective and safest option at volumes above roughly 10,000 litres per shipment on a regular trade lane.
Specific scenarios where ISO tanks outperform alternatives include:
- Regular bulk imports or exports of solvents, acids, resins, or food-grade liquids where drum handling costs are significant
- Shipments requiring heated transport for viscous or temperature-sensitive chemicals
- Intermodal routes combining sea freight with road or rail legs, where the standardized frame simplifies transshipment
- Supply chains where product purity is critical and each transfer point introduces contamination risk
- Situations where the shipper wants to consolidate multiple product lines into one container format across their logistics network
Conversely, if volumes are low, the product is sold in retail-sized units, or the destination requires final-mile delivery in small quantities, IBCs or drums remain more practical. The decision ultimately comes down to volume, frequency, product sensitivity, and total landed cost per unit.
How KEMITO helps with ISO tank chemical logistics
KEMITO is a full-service chemical logistics provider with direct experience managing ISO tank operations across EMEA and worldwide destinations. As a specialist in chemical transport and storage, KEMITO offers end-to-end support for shippers who want to move bulk liquids safely and efficiently. Key capabilities include:
- Heated ISO tank services for temperature-sensitive and viscous chemicals
- Intermodal transport by road, rail, and sea using a dedicated fleet of ADR-certified drivers and equipment
- Chemical storage and drumming at distribution centres across Belgium, France, Italy, the Netherlands, Turkey, and the United Kingdom
- End-to-end supply chain management including customs, freight forwarding, and blending or repacking at destination
- Flexible solutions for single shipments and fully outsourced distribution programmes
Whether you are shipping for the first time in ISO tanks or looking to optimize an existing bulk chemical supply chain, KEMITO provides the expertise and infrastructure to make it work. Contact the KEMITO team to discuss your requirements and receive a tailored logistics solution.