What Is an ISO Tank Container?
An ISO tank is a stainless-steel pressure vessel inside a standard 20-foot ISO frame. It's designed to transport bulk liquids, gases, and powders internationally and domestically using any mode — ship, rail, and truck — without transferring the product between vessels.
ISO Tank Specifications
| Spec | Standard ISO Tank |
|---|---|
| Frame Size | 20 ft × 8 ft × 8 ft 6 in (standard ISO) |
| Tank Capacity | 21,000–26,000 liters (5,500–6,870 gal) |
| Shell Material | Stainless steel 316L |
| Max Working Pressure | 4–6 bar (standard) / up to 22 bar (gas) |
| Temperature Range | −40°F to +300°F (with insulation/heating) |
| Tare Weight | 7,100–8,200 lbs |
| Max Payload | ~46,000 lbs (20,900 kg) |
Types of ISO Tanks
| Type | UN Portable Tank Code | Use Case |
|---|---|---|
| T11 | Standard liquid | Chemicals, food-grade liquids, oils |
| T14 | Hazardous liquid | Corrosives, toxic chemicals |
| T20 | Pressurized gas | LPG, ammonia, chlorine |
| T50 | Liquefied gas | Refrigerants, propane |
| T75 | Cryogenic | LNG, liquid nitrogen, liquid oxygen |
| Swap Body | Domestic only | Wine, juice, edible oils (US/EU) |
What Can You Ship in an ISO Tank?
Food & Beverage:
- Edible oils (olive, palm, soybean)
- Wine, fruit juice, concentrates
- Liquid sugar, glucose syrup, molasses
- Dairy (milk, cream — insulated/heated tanks)
Chemicals:
- Solvents (methanol, ethanol, acetone)
- Acids (sulfuric, hydrochloric, phosphoric)
- Caustics (sodium hydroxide)
- Resins, latex, adhesives
Petroleum & Fuels:
- Lubricating oils, base oils
- Biodiesel, ethanol fuel
- Bitumen (heated tanks)
Specialty:
- Pharmaceutical intermediates
- Liquid fertilizers
- Hydrogen peroxide
ISO Tank vs. Alternatives
| Factor | ISO Tank | Flexitank | Drums (55 gal) |
|---|---|---|---|
| Capacity | 26,000 L | 24,000 L | 208 L × 80 = 16,640 L |
| Cost per Liter | $0.03–0.05 | $0.02–0.04 | $0.08–0.15 |
| Reusable | Yes (20+ years) | No (single use) | Yes |
| Hazmat Eligible | Yes | Limited | Yes |
| Cleaning Required | Yes (between loads) | N/A | Yes |
| Intermodal | Ship/Rail/Truck | Truck only | Any |
When ISO tanks win:
- Hazardous or corrosive liquids (flexitanks can't handle them)
- Repeat shipments on the same lane (reusable = lower long-term cost)
- Temperature-sensitive liquids needing heating/insulation
- Intermodal movements (ship to rail to truck)
Regulatory Requirements
- DOT/FMCSA: Tanks must meet DOT SP or UN T-code specifications for US road transport
- IMDG Code: Required for ocean transport of dangerous goods
- FDA/FSMA: Food-grade tanks need FDA-compliant cleaning and documentation
- Customs: ISO tanks clear customs like standard 20' containers — same entry process
- Cleaning: Must be cleaned and inspected at certified depots between loads. A Certificate of Cleanliness is required before reloading
US ISO Tank Depots & Cleaning Stations
Major cleaning/depot locations:
- Houston, TX — Largest chemical corridor, multiple depots
- Newark/Elizabeth, NJ — Port of NY/NJ region
- Los Angeles/Long Beach, CA — West Coast hub
- Savannah, GA — Southeast gateway
- Chicago, IL — Rail intermodal hub
Cost Factors
| Cost Component | Typical Range |
|---|---|
| Tank Lease (per trip) | $800–$2,500 |
| Ocean Freight (20' slot) | Standard 20' container rate |
| US Drayage | $400–$900 |
| Cleaning (food grade) | $300–$600 |
| Cleaning (chemical) | $500–$1,500 |
| Heating (if required) | $200–$500 |
The Bottom Line
ISO tanks are the most efficient and safest way to move bulk liquids — especially hazmat, food-grade, and temperature-sensitive commodities. They reduce handling risk, lower per-unit shipping costs on repeat lanes, and work seamlessly across ship, rail, and truck.
Shipping bulk liquids? Contact Indray Inc for ISO tank logistics and competitive rates.
