A tank container is built to the ISO Standard, making it suitable for different modes of transportation. Both hazardous and non-hazardous products can be transported in tank containers.
A tank container is a vessel of stainless steel surrounded by an insulation and protective layer of usually Polyurethane and aluminum. The vessel is in the middle of a steel frame. The frame is made according to ISO standards and is 29.8556 feet (9.10 meters) long, 7.874 feet (2.40 meters) wide and 7.874 feet (2.40 meters) or 7.874 feet 6 inches (2.55 meters) high. The contents of the tank ranges from 27,000 to 40,000 liters (5,900 to 8,800 imp gal; 7,100 to 11,000 US gal). There are both smaller and larger tank containers, which usually have a size different from the ISO standard sizes. The trade organization @TCO estimates that at the end of 2012 the global fleet of tank containers is between 340,000 and 380,000. Most of these tank containers are owned by operators and leasing companies.
There are hundreds of tank container operators worldwide, that can vary on the service they offer. The bigger operators typically offer a wide range of services, while smaller operators may only offer services in one region or with one type of tank. Among the biggest tank container operators are; Stolt Tank Containers, Hoyer, Bulkhaul, NewPort and VOTG. As of 2012, Agmark Logistics is North America's largest food grade tank container operator.
History of the tank container 
The tank container concept was designed by Bob Fossey, an engineer who worked for Willimas Fairclough in London. In 1964 he made a swap body tank for combined transport by truck and train, but this tank was not yet constructed according to ISO standards. In 1966, the first commercial production occurred and one year later the first tank container according to ISO standards was developed. The first mass-produced tank containers were purchased by Trafpak, a part of Pakhoed.
In the early 70's, the tank container evolved to its current form and the production was also well underway. In the early days, production took place in Europe. In 2010 and afterward, production is mainly in China and South Africa.
A tank container can be loaded and unloaded from the top and the bottom. On a standard tank container there is a manhole and at least one valve on the top, and there is a valve at the bottom. Loading and unloading is done by connecting hoses of the loading and unloading facility to the valves of the tank. The loading or unloaded is often done using a pump. Depending on the installation and regulation of certain products, it is determined how the tank container should be loaded or unloaded.
- Swap Body tank - a swap body has a bigger tank which is larger than the frame, usually 23 or 25 feet (7.01 or 7.62 meters) long
- Foodgrade tank - a standard tank container which can only be loaded with foodgrade products
- Reefer tank - a tank with the ability to cool the product to be transported
- Gas tank - a tank that is suitable for the transport of gases
- Silo Tank - a tank for the transport of grains and powders