Packing Formats by Volume: Cylinders, Drums, IBCs and ISO Tanks
· RIBOLUO CHEMICALS (ZHEJIANG) CO., LTD.
Volume picks the format, but the format also picks the freight, the marks and what you can verify on arrival. Service-scale orders travel in cans and cylinders; mid-volume moves in cylinder pallets, drums and IBCs; bulk goes into ISO tanks. Settle the format before the price.
Why is the package part of the specification?
For a dangerous good the packaging is the approved means of containment: the UN code on it, the packing group it was approved for and the packing instruction in the modal regulations make the shipment legal. A format change is a specification change — marks, net weight and documents move with it.
Which format fits which volume?
| Format | Typical capacity | Order scale | What to confirm |
|---|---|---|---|
| Can / non-refillable cylinder | 0.4–1 kg cans; 10–13.6 kg and 22.7 kg cylinders | single-service and service-van stock | non-refillable authorisation, valve type, legible marks |
| Refillable cylinder | 13.6 / 55.8 / 108.4 / 450 kg water capacity in US trade sizes (30 / 123 / 239 / 1,000 lb); 400 / 800 / 926 / 1,000 L water capacity in export catalogues | pallets, LCL, FCL | cylinder standard, valve outlet, test date, declared net weight |
| Drum | 200 L nominal (55 US gal = 208 L); UN 1A1 or 1A2 | LCL and FCL liquids | UN code, packing group letter, net mass against liquid density |
| IBC | typically 1,000 L; 3,000 L is the ceiling by definition | mid-volume liquids | type code (e.g. 31HA1), capacity, tare, maximum gross mass |
| ISO tank | 14,000–26,000 L; most common 20,000–24,000 L | bulk, one order per unit | T-code, working pressure, cleaning, free days |
One line in that table is a boundary: liquefied gases cannot travel in drums or IBCs. They need pressure-rated containment, which means cylinders or ISO tanks. Drums and IBCs are for liquids handled at ambient pressure.
Cylinders — what the sizes mean
In the US trade, refillable refrigerant cylinders are sold by water capacity — 30 lb, 123 lb, 239 lb and 1,000 lb — built to DOT-4BA or DOT-4BW with published service pressures of 260–400 psig. In the export trade, sizes are quoted in litres of water capacity, and 400 L, 800 L, 926 L and 1,000 L appear in supplier catalogues.
Water capacity is the denominator, not the contents: net mass is set by the filling ratio for that gas under the framework in force, so the same 926 L cylinder carries different net weights of different gases. A cylinder supplied without a legible water capacity and tare cannot be verified at receipt.
Refillable units circulate on deposits and return legs; non-refillable ones are one-way and paid for every time.
Drums — the density arithmetic
A 55 US gallon drum is 208 L, coded 1A1 for a non-removable head and 1A2 for a removable head. Net mass is never fixed: net = nominal volume × practical fill × density. Dichloromethane at 1.322 kg/L filled to 95% of a 200 L drum gives 190 L, roughly 251 kg net. A price per drum is therefore not a price per kilogram, which is why the packing list has to state net weight.
IBCs — 1,000 L typical, 3,000 L is the ceiling
By definition an intermediate bulk container holds 3,000 L or less and is designed for mechanical handling. The workhorse is the 1,000 L composite unit — a plastic inner bottle in a steel cage, coded 31HA1.
The data plate is the part to read: capacity, tare mass, stacking test load, maximum permissible gross mass, and a packing group letter, where Y approves the unit for groups II and III and Z for group III only. That letter is where a specification change can invalidate a packaging decision: move a product into packing group I — hydrogen peroxide does that above 60% under 49 CFR 172.101 — and an IBC marked Y is no longer approved containment.
ISO tanks — one unit, one order
An ISO tank is a pressure vessel inside a standard 20 ft frame: 14,000–26,000 L capacity, 20,000–24,000 L most common, tare 3,200–3,700 kg, maximum gross mass up to 36,000 kg. The T-code defines the maximum allowable working pressure and the minimum test pressure; T50 covers pressurised gases.
Two points surprise buyers. The rated payload is rarely reachable — liquid density, and for a liquefied gas the fill limit, cap the net mass, so compare declared net weight rather than tank volume. And the unit is normally leased: free days, charges after them, cleaning and a return leg all sit in the landed cost.
Which format is cheaper per tonne?
Freight per tonne is the driver; for dense liquids the container’s payload ceiling, not its volume, sets the limit. A 20 ft dry container offers roughly 33 m³ of usable volume, a tare near 2,300 kg and a maximum payload around 28,200 kg. At 1.322 kg/L, dichloromethane reaches that payload at about 21,000 L, so most of the space travels empty. Carrier maximum gross weights for general purpose 20 ft units can be higher, up to 32,500 kg, but container rating and road limit have to agree.
Returnable formats move cost from price into logistics: deposits, return freight, cleaning, and charges for days held past the free period; non-refillable cylinders instead carry the container cost in the unit price.
What has to match on the documents and the marks?
- the packaging marks: UN code, capacity, tare, test and inspection dates
- the transport document and packing certificate, and the packing list net weight consistent with format and density
- the COA for the grade — the format does not replace the specification
- at receipt: net = gross − tare, the only check that works without opening the package
FAQ
Can one order be split across formats? It can, but each format carries its own marks and net weight, and the mixed load must still satisfy segregation and packing rules.
Why does a 1,000 L IBC not hold 1,000 kg? Capacity is a volume, the shipment a mass: net content is volume × density, capped by maximum permissible gross mass minus tare.
Can refrigerants be shipped in IBCs or drums? No. Liquefied gases require pressure-rated containment: a cylinder or an ISO tank.
What limits the load in a 20 ft container — volume or weight? For dense liquids, weight: check the payload figure, then the volume it allows at your product’s density.
Putting a format on the enquiry
RIBOLUO CHEMICALS (ZHEJIANG) CO., LTD. is a distribution platform: we source, consolidate and document, and the format on your purchase order is the format we document. If the volume does not match the format you have named, we will say so and put the alternative in writing with its marks and net weight.
Related guides
- Can different chemicals travel in one container? Mixed loads, consolidation and the limits
- Low-GWP refrigerants: which grades are in our catalogue, and how to choose one
Sources
- ISO tank container T-codes, capacity and specifications (TraceContainer technical guide): https://www.tracecontainer.com/container-types/tank-container
- ISO tank fleet capacities — 21,000–26,000 litre units (CS Leasing): https://www.cslintermodal.com/iso-tanks
- Steel refillable cylinders for refrigerant — standard specifications (Worthington Enterprises, PDF): https://buildingproducts.worthingtonenterprises.com/docs/default-source/default-document-library/worthington_refrigerant_refillable.pdf
- Refrigerant cylinder water capacities in the export trade (400 / 800 / 926 / 1,000 L) (supplier product catalogue, Quzhou Jinyuan Hongtai Refrigerant): http://jx-refrigerant.com/product/135
- Packaging and cylinder types for refrigerant gas (KOOLEX): https://koolex.ca/packaging
- 49 CFR § 178.504 — Standards for steel drums (codes 1A1, 1A2) (Cornell LII, eCFR): https://www.law.cornell.edu/cfr/text/49/178.504
- UN intermediate bulk containers (IBCs) — definition and the 3,000 L capacity limit (Transport Canada): https://tc.canada.ca/en/dangerous-goods/containers/intermediate-bulk-containers-ibcs
- ADR chapter 6.5 — construction and testing requirements for IBCs (UNECE, PDF): https://www.unece.org/fileadmin/DAM/trans/danger/publi/adr/adr2005/English/Part6_ch6-5.pdf
- IBC UN code explained: 31HA1, capacity, tare, maximum gross mass, packing group letter (IBC Container reference): https://ibc-container.org/en/ibc-un-code
- 20-foot container dimensions, tare and payload (iContainers): https://www.icontainers.com/help/20-foot-container/
- Container specification — maximum gross weights (Hapag-Lloyd, PDF): https://www.hapag-lloyd.com/content/dam/website/downloads/press_and_media/publications/15211_Container_Specification_engl_Gesamt_web.pdf
- Dichloromethane — density 1.322 kg/L at 68 °F (PubChem CID 6344): https://pubchem.ncbi.nlm.nih.gov/compound/6344
- Hydrogen peroxide, aqueous solution — UN number and packing group by concentration, 49 CFR 172.101 reference (Alliance Chemical DOT reference page): https://docs.alliancechemical.com/dot/hydrogen-peroxide
Prepared by RIBOLUO CHEMICALS (ZHEJIANG) CO., LTD., a member of Hangrui Group — a chemical distribution platform (sourcing, consolidation and documentation), not a manufacturer. Capacities, marks and weights quoted here are typical published figures; for any shipment the binding figures are those on the packaging specification sheet, the marks on the unit and the transport documents for that route.
Need current specs, quota status, or a mixed-load quote for Cylinders, Drums, IBCs and ISO Tanks? Contact tom@riboluo.com with your spec and delivery location.