Approximately only half of all containers are owned by shipping lines. The rest are leased, which usually run from one to 10 years. Once an ISO tank has been tagged for food, it can no longer be used for other types of cargo. The same goes for ISO tanks tagged for chemicals. This is to prevent contamination risk.Once an ISO tankhas been tagged for chemicals, the type of chemical it can next transport depends on the three previous chemicals it has transported. Maersk is the only shipping line that has a GPS equipped on its reefer containers, all 270,000 of them. Reefer containers do not generate cold air, they only maintain temperatures! They are not capable of reverting to their original temperatures. Approximately 97% of all shipping containers are manufactured in China. That’s due to the lower labor costs. Plus, it’s easier to produce the container close to where most of the world’s products are produced. If well-maintained, a container has a lifespan of around 30 years – perhaps more! 40-foot containers tend to outlive 20-foot containers. This is because they are not usually packed to its weight limit, unlike the 20-foot containers.