If you’re shipping liquid bulk products, you are likely familiar with bulk liquid tankers, along with totes and drums that may routinely transport your products. What you may be less familiar with are ISO tanks – another transport option for liquid bulk shippers that is becoming increasingly popular. In this article, we’ll introduce you to these tanks and tell you how ISO tank trucking companies can help you get your products in motion.
ISO tanks are steel cylinders that sit within a metal, wall-less box frame. They are given the name “ISO” tanks because they were designed in accordance with ISO standards from the International Organization for Standardization. ISO tanks are generally used to house bulk liquids, both hazmat and non-hazmat, for transportation and storage.
Design & construction
ISO tanks consist of a steel outer shell and typically include a liner (e.g., chemical liner, rubber lined, plating) that can be replaced during cleaning. Different liners are used for different products. For example, an ISO tank used for hazardous corrosives will likely have a different liner than a tank used for food products. The tank’s fittings and valves can also be customized to manufacturer/shipper specifications.
Storage capacity
Most ISO tanks are approximately 20’ long and 8’ tall and can hold roughly the same amount of liquid as a standard liquid bulk tank. There are also 40’ versions of the ISO tank that have a long, thin appearance.
Products stored
Nearly any liquid bulk product can be shipped in an ISO tank. Common products include chemical products, both hazmat and non-hazmat. These tanks have become a go-to option for products like corrosives that eventually wear down a tank’s structural integrity. It’s much cheaper to replace an ISO tank than an entire bulk tanker. Food-grade products and even Kosher food-grade products are also shipped in ISO tanks.
Tank storage
ISO tanks are typically stored at an “ISO depot,” which is basically an outdoor warehouse with ISO tanks stacked high and wide. However, manufacturers and shippers may also store tanks on site.
Tank washing
ISO tanks can be washed out at a common tank wash facility. However, most tanks are cleaned and stored at ISO depots, where their liners can be replaced if necessary.
ISO tank trucking companies
ISO tanks are typically transported by drayage providers and carriers that receive chassis from ‘power-only’ companies. ISO tank trucking is also managed by 3PL freight brokerages that specialize in bulk freight.
Loading and unloading
The ISO tank will be loaded at the top or bottom using a pump or air compressor. The tank is typically filled at a plant, dropped onto a chassis (if plant has its own crane), and then shipped to an ISO depot by a transportation provider for storage or directly to the recipient facility. For plants that do not have a crane onsite, heavy-duty jacks can be used to move empty tanks onto the chassis before being filled.
For unloading, the carrier will typically use a pump or air compressor to unload the product from the tank’s discharge valve. Some chassis are built so that the tank can tilt downward during the unloading process. After unloading, the empty tank will be returned to the ISO depot or the originating plant.
While ISO tank transport offers numerous advantages, it also comes with certain limitations.
1. Limitations on Over-the-Road (OTR) MovesOTR transport of ISO tanks is often restricted to shorter runs due to logistical and economic constraints. Most ISO tanks are dedicated to transporting a single type of product, which means that carriers are typically unable to reuse them during the return trip after unloading. Consequently, carriers are typically reluctant to engage in long-haul transport of ISO tanks unless economically justified by higher freight charges or other compensatory factors.
2. Specialized Equipment Requirements for Loading and UnloadingThe operation of loading and unloading ISO tanks requires specialized equipment, which is not universally available across all carriers. Facilities responsible for the loading and unloading need to be equipped with appropriate hoses, fittings, pumps, and a source of pressurized air or nitrogen gas. The lack of such equipment can lead to delays, increased handling costs, and restricted choice of carriers, impacting the overall efficiency of bulk liquid transport.
3. Regulatory and Compliance ChallengesTransporting liquids, particularly hazardous ones, in ISO tanks is subject to stringent regulatory requirements that vary by region and the nature of the cargo. Compliance with these regulations requires thorough documentation, proper labeling, and adherence to safety protocols, adding layers of complexity and the potential for regulatory hurdles. Failure to comply can result in fines and shipment delays.
When it comes to moving bulk freight—whether in an ISO tank, liquid bulk tanker, or dry bulk trailer—the logistics are complex, the regulations are strict, and the margin for error is small. That’s where a specialized bulk freight broker like Bulk Connection adds measurable value.
Access to a Vetted, Specialized Carrier Network
Bulk Connection maintains a vast network of pre-qualified carriers across North America, including those with ISO tank capabilities. Whether your shipment requires a standard tank truck or a container that will cross oceans and borders, Bulk Connection can match your load with the right equipment and expertise—fast.
Product and Mode Flexibility
One of the biggest challenges in bulk shipping is finding capacity for your specific product and mode. From hazardous chemicals to food-grade materials, and from ISO tank containers to pneumatic trailers, Bulk Connection understands the nuances of each transport method and can pivot quickly based on availability, geography, or urgency.
ISO 9001:2015 Certified Processes
Bulk Connection’s ISO 9001:2015 certification isn’t just a badge—it’s a commitment to documented, measurable quality in every shipment. This level of operational discipline means:
Bulk Connection is a liquid bulk freight specialist with one of the largest networks of bulk carriers – including ISO tank trucking companies – in North America. If you’d like to learn more about entrusting your bulk freight transportation needs with a true expert, contact Bulk Connection today.