Reference
Sixty IBC tote terms, defined.
Every trade develops shorthand, and this one has more than most because it sits between plastics manufacturing, freight, chemical handling and food safety regulation. Here is the whole vocabulary in one place.
The short answer
Definitions for the working vocabulary of intermediate bulk containers — from aromatic solvent and boss through crazing, heel, rebottle, stress-whitening and sump to UN31HA1/Y and weld node.
- Aromatic solvent
- A solvent containing a benzene ring — toluene, xylene, styrene. Permeates polyethylene and permanently compromises the wall. On every reconditioner's exclusion list.
- ATP swab
- A surface test measuring adenosine triphosphate as a proxy for biological residue, read in relative light units against a written limit. Used to verify food-grade washes.
- Bladder
- Informal term for the inner bottle. Technically incorrect — a bladder is flexible and an IBC bottle is rigid — but widely used.
- Boss
- The moulded polyethylene collar on the bottle that carries the outlet thread. Seals against a flat gasket, not on the thread itself.
- Bottle
- The blow-moulded HDPE vessel inside the cage. About 40 lb on a 275-gallon unit.
- Bund
- A containment structure sized to hold a percentage — usually 110% — of the largest single vessel within it. Required for many hazard classes.
- Buttress thread
- A coarse, asymmetric thread form used on IBC outlets. S60x6 and S70x6 are the common sizes. Not interchangeable with NPT.
- Cage
- The welded, galvanised steel wire frame that carries the structural load. The bottle is a liner; the cage is the structure.
- Camlock
- A quick-connect coupling using cam levers rather than threads. Types A through F denote the mating configuration.
- CIP
- Clean-in-place. Cleaning a vessel without dismantling it, usually via a spray ball. Routine for stainless, hard on polyethylene.
- Composite IBC
- An IBC with a rigid plastic inner and a separate outer casing — the standard caged tote. Distinguished from all-metal or all-plastic designs.
- Conductivity check
- Comparing the electrical conductivity of final rinse water against incoming water to verify the absence of dissolved ionic residue.
- Crazing
- A network of fine surface cracks in polyethylene caused by stress, chemistry, UV or freezing. Permanent, progressive and a reason to retire the bottle.
- Dedicated service
- A container permanently assigned to one product and never rotated back into general use. Standard practice for pesticides.
- Diversion rate
- The proportion of intake weight that leaves as a working container or a recovered material stream rather than as landfill.
- Drop test
- Part of UN certification: a filled unit is dropped from a specified height onto a rigid surface and must not leak.
- EPDM
- Ethylene propylene diene monomer. The default gasket elastomer for aqueous chemistry, caustics, dilute acids and food work. Poor with oils.
- Fertigation
- Delivering fertiliser through an irrigation system. A major agricultural use of IBC totes.
- First-flush diverter
- A device that captures and discards the opening volume of roof runoff before it reaches a rainwater tank.
- Fork pocket
- The opening in the pallet base that accepts forklift tines. Two-way bases accept forks on one axis only.
- Galvanising
- Zinc coating applied by hot dip to protect the steel cage. Corrosion at weld nodes matters; surface rust on a bar does not.
- GMA pallet
- The 48 × 40 inch Grocery Manufacturers Association pallet footprint that IBC bases are built to match.
- Grade
- A seller's classification of a used tote's condition. Not standardised across the industry — always ask for written criteria.
- Gross weight
- Container plus contents. The only weight your forklift, racking and floor care about.
- HDPE
- High-density polyethylene. The bottle material. Food-contact use depends on the resin and documentation; check current regulations.
- Heel
- Residual liquid remaining after discharge. A sump-bottom tote drains more completely than a flat-bottom one.
- Hydrostatic test
- Filling and pressurising a container with liquid to verify it does not leak or deform. Part of UN design testing and of most reconditioning processes.
- IBC
- Intermediate bulk container. Anything between a drum and a bulk tanker, typically 120–550 gallons.
- Leakproofness test
- A periodic pressure test on a UN-marked IBC in dangerous-goods service, with the date recorded on the data plate. Check current regulations for intervals.
- Liner
- A flexible or rigid inner vessel. In a composite IBC, the bottle acts as a liner within the structural cage.
- LTL
- Less than truckload. Freight priced per pallet position rather than per truck.
- Manway
- A large access opening, usually 18–20 inches, found on stainless IBCs and not on composite ones.
- NPT
- National Pipe Taper. A tapered US pipe thread sealing on interference plus sealant. Not interchangeable with buttress threads.
- Packing group
- A danger classification under transport regulations. I is high, II medium, III low. Determines which UN marking a container needs.
- Passivation
- Restoring the chromium-oxide layer on stainless steel with citric or nitric acid after fabrication or repair. Skipping it creates rust sites.
- Pallet base
- The structure carrying the cage and providing fork pockets. Steel, composite, wood or moulded plastic.
- Prior contents
- What was previously in a used container. The most consequential fact about it, and entirely absent from any grade letter.
- Quarantine
- A physically separated area where units with unknown or excluded prior contents are held pending a decision.
- Rebottle
- To fit a new HDPE bottle into an existing inspected cage and pallet. Reuses the steel cage and base.
- Recondition
- To wash, test and re-gasket a used container while retaining its original bottle. Keeps the most original material in use.
- Regrind
- Shredded, washed reclaimed plastic. Sold into non-food moulding; never back into a food-contact or pressure-rated bottle wall.
- Rinse-water check
- Verifying wash completion by comparing final rinse water against incoming water on pH or conductivity.
- S60x6
- The most common IBC outlet thread: 60mm nominal, 6mm pitch, buttress form. Measures about 61mm across the crests.
- S70x6
- A larger outlet thread found on many 330-gallon units and European bottles. Measures about 71mm.
- Saponification
- The reaction of fats with alkali to form soap. The mechanism by which a caustic wash pass clears fatty residues.
- Scrap grade
- A unit that cannot be returned to liquid service. Dismantled for material recovery rather than sold.
- SG
- Specific gravity. The density of a liquid relative to water. Multiply gallons × 8.34 × SG to get net weight in pounds.
- Spill pallet
- A containment pallet designed to catch leakage from one or more totes. Adds about 6 inches to overall height.
- Stack rating
- The number of units that may be stacked, stated separately for loaded and empty, at rest and in transit.
- Stress-whitening
- A pale chalky band where polyethylene has been deformed beyond its elastic limit. Permanent, and a reliable predictor of a split.
- Sump
- The moulded low point at the discharge end of the bottle, sloping toward the outlet so residual liquid drains to the valve.
- Surfactant
- A detergent that reduces surface tension and carries away what an alkaline pass has lifted. Mandatory after caustic on fatty residues.
- Tare
- The empty weight of a container including cage, base, valve and cap. About 135 lb on a composite 275.
- Tri-clamp
- A sanitary clamp fitting standard on stainless vessels, using a gasket compressed between two ferrules.
- Triple rinse
- Three separate rinses with fresh water between each. A regulatory term in some contexts and a common minimum in reconditioning.
- UN31HA1/Y
- The marking for a composite IBC for liquids with a plastic inner and steel outer, approved for packing groups II and III.
- Vented cap
- A fill cap with a one-way membrane admitting air as liquid leaves. Prevents vacuum collapse during gravity discharge.
- Viton (FKM)
- A fluoroelastomer gasket material for oils, fuels, aromatics and high temperature. Poor on caustics relative to EPDM.
- Wash record
- The document stating chemistry, concentration, temperature, dwell, rinse count and operator for a specific cleaning pass.
- Weld node
- The point where cage bars cross and are welded. Where structural corrosion matters, as distinct from cosmetic rust on a bar.
Usage notes
Three terms people use wrongly.
"Food grade"
Used as though it describes a wash standard. It describes material compliance plus documented history. No amount of cleaning converts an industrial container.
"FDA approved"
Not how containers are regulated. The FDA regulates food-contact materials rather than approving individual containers. Ask what documentation the claim rests on.
"Grade A"
Treated as an industry standard. There is no standard, no registry and no enforcement. It means whatever the seller's written criteria say — if they have any.
Abbreviations
The acronyms you will meet on a quote or a data plate.
| Abbreviation | Stands for | Context |
|---|---|---|
| IBC | Intermediate bulk container | Anything between a drum and a bulk tanker |
| HDPE | High-density polyethylene | The bottle material |
| PP | Polypropylene | Valve bodies, some caps |
| EPDM | Ethylene propylene diene monomer | The default gasket elastomer |
| FKM | Fluoroelastomer | Viton is a trade name for this |
| NBR | Nitrile butadiene rubber | Buna-N; cheap and usually wrong |
| PTFE | Polytetrafluoroethylene | High-end gasket and seal material |
| ESCR | Environmental stress crack resistance | The property surfactants attack |
| SG | Specific gravity | Density relative to water |
| GMA | Grocery Manufacturers Association | The 48 × 40 in pallet footprint |
| EUR | European pallet standard | 1200 × 1000 mm |
| NPT | National Pipe Taper | US tapered pipe thread |
| LTL | Less than truckload | Freight priced per pallet position |
| FTL | Full truckload | One truck, one load |
| CIP | Clean in place | Cleaning without dismantling |
| ATP | Adenosine triphosphate | Biological residue swab test |
| RLU | Relative light units | The unit an ATP swab reads in |
| PG | Packing group | Danger classification: I, II or III |
| UN31HA1 | Composite IBC for liquids | Plastic inner, steel outer |
| DOT | Department of Transportation | US transport regulator |
| ADR | European road transport agreement | European counterpart to US DOT hazmat rules |
| IMDG | International Maritime Dangerous Goods | Sea freight |
| SDS | Safety data sheet | Section 9 has specific gravity |
| HACCP | Hazard analysis and critical control points | Food safety plan framework |
| FSMA | Food Safety Modernization Act | US food records requirements |
| NSF | NSF International | Certifier for potable water components |
| RCRA | Resource Conservation and Recovery Act | US hazardous waste |
| SPCC | Spill Prevention, Control and Countermeasure | Oil storage rule |
| Ra | Roughness average | Surface finish on stainless |
| DE | Dextrose equivalent | Corn syrup grade, e.g. 42 DE |
| UAN | Urea ammonium nitrate | Liquid fertiliser, e.g. UAN 32 |
Units
Conversions worth memorising.
| Quantity | Equals | Use |
|---|---|---|
| 1 US gallon | 3.785 litres | Everything |
| 1 US gallon of water | 8.34 lb | The weight formula |
| 1 litre of water | 1.0 kg | Metric weight |
| 1 cubic foot | 7.481 US gallons | Containment bund sizing |
| 1 cubic metre | 264.2 US gallons | Metric volume |
| 1 US oil barrel | 42 US gallons | Petroleum |
| 1 imperial gallon | 1.201 US gallons | UK and Canadian legacy |
| 1 pound | 0.4536 kg | Weight |
| 1 short ton | 2,000 lb | US scrap and freight |
| 1 metric tonne | 2,205 lb | Carbon reporting |
| 1 inch of rain on 1,000 sq ft | 623 US gallons | Rainwater sizing |
| 1 psi | 2.31 ft of water head | Gravity pressure |
| 1 foot of elevation | 0.433 psi | Gravity feed |
| 1 kWh | 3,412 BTU | Heating calculations |
| 1 kg CO₂e | 2.205 lb CO₂e | Impact reporting |
Trade usage
Words used differently here than elsewhere.
Several ordinary words carry a specific meaning in this trade, and a few carry a meaning that is simply wrong. Worth knowing which is which.
| Word | Everyday meaning | In this trade | Watch for |
|---|---|---|---|
| Grade | Quality level | A written classification of physical condition | It is not standardised between sellers |
| Clean | Free of dirt | No free liquid, no film, no odour, passed a test | Clean is not sterile and not food grade |
| Food grade | Safe for food | Compliant materials plus documented history | No wash creates it |
| Recycled | Reprocessed | Ground into flake; the container is destroyed | Reuse comes first where the container is sound |
| Reconditioned | Restored | Original bottle washed, tested and re-valved | Not the same as rinsed |
| Rebottled | — | New bottle in an existing cage | Often sold simply as 'reconditioned' |
| Certified | Officially approved | Meaningless without naming the scheme | Certified by whom, to what? |
| Virgin | Unused | Never previously filled | Of the bottle, or the whole assembly? |
| Tested | Checked | A specific hydrostatic or leakproofness test | Ask which test |
| Rated | Approved | Carries a UN marking with a live test date | The date matters more than the mark |
| Heel | Back of a foot | Residual liquid that will not come out | It is a disposal and contamination issue |
| Crazing | Fine cracks in glaze | Microscopic fracture in polyethylene | Permanent; retire the bottle |
Glossary questions
What does IBC stand for?
IBC stands for intermediate bulk container: anything between a drum and a bulk tanker. The common composite IBC is an HDPE bottle inside a galvanised steel cage on a pallet base, usually 275 or 330 gallons.
What is a heel in an IBC tote?
The heel is the residual liquid left in a container after discharge. It is a disposal problem, a contamination risk for the next fill and, on expensive product, a real cost that is rarely tracked.
What does UN31HA1 mean on an IBC tote?
UN31HA1 identifies a composite IBC for liquids with a plastic inner receptacle and a steel outer frame. The letters and numbers that follow on the data plate give the packing group, test dates and load ratings.
What is the difference between rebottling and reconditioning?
Reconditioning washes, tests and re-gaskets the original bottle and cage. Rebottling replaces the bottle with a brand-new HDPE one inside the inspected original cage, giving a near-new interior while reusing the cage.
What is stress whitening on an IBC bottle?
Stress whitening is a pale, chalky band where the polyethylene has been strained past its limit, usually at a corner. It never recovers, so unlike cosmetic scuffing it is a structural defect that counts against the bottle.