Industries · Chemical & Coatings
Compatibility, marking, gasket, weight. In that order.
Four decisions determine whether a container works for a chemical application, and they have to be made in sequence. Get the compatibility wrong and nothing else matters. Get the gasket wrong and you will discover it at three in the morning on a warehouse floor.
The short answer
HDPE suits most aqueous chemistry, acids and caustics at working dilution, alcohols and glycols. It does not suit aromatic or chlorinated solvents, strong oxidisers at concentration, or hot fills. Road shipment of a regulated hazardous material generally needs a UN-marked assembly suited to the packing group, with current test dates — check current regulations. Above SG 1.3, consider a 220.
Step one
HDPE compatibility, at a glance.
General guidance for ambient temperature and typical working concentrations. Always verify against your own SDS and a manufacturer's compatibility chart — concentration and temperature both move these calls.
| Chemical class | HDPE | Gasket | Notes |
|---|---|---|---|
| Mineral acids, dilute | Excellent | EPDM | Sulphuric, hydrochloric, phosphoric at working dilution |
| Mineral acids, concentrated | Good to fair | Viton | Check temperature; concentrated nitric is a stainless job |
| Caustics (NaOH, KOH) | Excellent | EPDM | Watch the density — 32% NaOH is around SG 1.35 |
| Alcohols | Excellent | EPDM | Methanol, ethanol, IPA generally fine |
| Glycols and coolants | Excellent | EPDM | Standard application |
| Aqueous detergents & surfactants | Excellent | EPDM | Watch for stress cracking with concentrates |
| Aliphatic hydrocarbons | Good | Viton | Some permeation over long storage |
| Aromatic solvents (toluene, xylene) | Poor | Viton | Permeates and swells the wall. Use stainless. |
| Chlorinated solvents | Poor | Viton or PTFE | Not an HDPE application |
| Strong oxidisers (conc. peroxide, hypochlorite) | Fair | Viton | Concentration dependent; venting needed |
| Latex emulsions and waterborne coatings | Excellent | EPDM | Agitation needed; settles hard |
| Solvent-borne coatings and inks | Poor to fair | Viton | Depends entirely on the solvent package |
Step two
Does it need a UN marking?
The question is not only whether the liquid is hazardous. It is whether it ships on a public road as a regulated material under a UN number and a packing group.
UN31HA1/Y is the marking you will commonly see on a composite IBC: rigid plastic inner with a steel outer casing, for liquids, packing groups II and III. It applies to the whole assembly — bottle, cage and base as a system — after design-type testing that typically covers drop, stacking, hydraulic pressure, leakproofness and vibration.
Three things people get wrong about it. First, it belongs to the assembly, not the bottle, so swapping components can void it. Second, it carries test dates and periodic retest requirements — a marking is not permanent. Third, it says nothing about food suitability; they are unrelated questions.
When you need a marked unit, ask the partner supplier for the marking, the most recent test date and who performed the test. Do not assume a marking stamped into the plate is current. Check current regulations for your shipment.
| Marking element | Means |
|---|---|
| UN | Packaging marked to the UN model regulations |
| 31 | IBC for liquids |
| HA1 | Rigid plastic inner, steel outer casing |
| Y | Packing groups II and III |
| Hydraulic test pressure | kPa figure on the plate |
| Max gross mass | kg figure — includes the container |
| Date of manufacture | Month and year |
| Retest dates | Periodic test and inspection; check current regulations for intervals |
Steps three and four
Gasket, then weight.
The gasket decides more than people think
The bottle is one material; the sealing system is three or four. Valve seat, flange gasket, cap gasket and any adapter seal all have to survive your liquid, and they are often the components that fail first.
EPDM is generally excellent on caustics, dilute acids and aqueous work, and poor on oils and aromatics. Viton is generally excellent on oils, fuels and aromatics, and less suited to strong caustics. Buna-N is cheap and is the wrong answer more often than it is the right one. PTFE-lined options exist for the difficult cases.
Ask the supplier to state the compound fitted on each unit. If you are running a fleet, keep the compound in your register — a common chemical incident starts with somebody fitting whatever gasket was in the drawer.
Density is a handling constraint
Chemical applications hit weight limits more often than most sectors, because chemistry is frequently much denser than water and nobody recalculates from the nominal capacity.
- Sulphuric acid 93%, SG 1.83 — about 4,330 lb in a full 275
- Ferric chloride 40%, SG 1.42 — about 3,390 lb in a full 275
- Caustic soda 32%, SG 1.35 — about 3,230 lb in a full 275
- Hydrochloric acid 32%, SG 1.16 — about 2,800 lb in a full 275
Above SG 1.3, consider a 220-gallon unit so you stay inside common forklift and rack ratings. A smaller container costs less than a dropped tote.
Chemical application questions
What chemicals can you store in an HDPE IBC tote?
Most aqueous chemistry, acids and caustics at working dilutions, alcohols, glycols, detergents, aqueous fertilisers and a wide range of process liquids. What HDPE generally does not tolerate is aromatic and chlorinated solvents, which permeate the wall, strong oxidisers at concentration, and hot fills above the manufacturer's rated temperature. Always check your specific SDS against a compatibility chart rather than trusting a category.
Do I need a UN-marked tote?
If the liquid ships on a public road as a regulated hazardous material, generally yes. A marking such as UN31HA1/Y applies to the complete assembly — bottle, cage and base together — and carries test dates. It is not a property of the plastic and it does not survive an arbitrary rebuild. Buyers in this sector typically include the UN number and packing group in their request so partner suppliers can say what they can offer; ask for the marking and test documentation, and check current regulations.
Can totes that held our chemistry be reconditioned?
It depends entirely on what it was. Aqueous chemistry, caustics, acids at working dilution and many process liquids generally wash out well. Aromatic solvents, polymerising resins and registered biocides generally do not — those units usually go to rebottling or material recovery instead. Include the SDS when you ask, and a partner supplier can tell you whether it is something they accept.
Why are dense chemicals often sold in 220 gallon totes?
Weight. Sulphuric acid at SG 1.83 in a full 275-gallon tote is about 4,330 lb gross, which exceeds the rating of a lot of forklifts and pallet racking. The same acid in a 220 is about 3,480 lb. It is a handling decision, not a chemistry one.
Compatibility, extended
Specific products rather than classes.
Class-level guidance is where compatibility advice goes wrong. These are commonly asked-about products at working concentrations and ambient temperature. Verify against your SDS.
| Product | Conc. | HDPE | Gasket | Approx. SG | 275 gross, approx. | Note |
|---|---|---|---|---|---|---|
| Sulphuric acid | 93% | Good | Viton | 1.83 | 4,330 lb | Consider a 220; weight is the limit |
| Sulphuric acid | 35% | Excellent | EPDM | 1.26 | 3,020 lb | Dilute is easier on everything |
| Hydrochloric acid | 32% | Good | Viton | 1.16 | 2,800 lb | Vent; fumes attack fittings |
| Phosphoric acid | 75% | Excellent | EPDM | 1.58 | 3,760 lb | Dense; consider a 220 |
| Nitric acid | 68% | Poor | — | 1.41 | — | Oxidiser; stainless |
| Sodium hydroxide | 50% | Excellent | EPDM | 1.53 | 3,640 lb | Dense and viscous when cold |
| Sodium hydroxide | 32% | Excellent | EPDM | 1.35 | 3,230 lb | A common concentration |
| Sodium hypochlorite | 12.5% | Fair | Viton | 1.20 | 2,890 lb | Degasses; vented cap needed |
| Hydrogen peroxide | 35% | Fair | Viton | 1.13 | 2,730 lb | Vent; dedicated service only |
| Ferric chloride | 40% | Excellent | Viton | 1.42 | 3,390 lb | Stains everything permanently |
| Aluminium sulphate | 48% | Excellent | EPDM | 1.33 | 3,190 lb | Water treatment staple |
| Ethylene glycol | 100% | Excellent | EPDM | 1.11 | 2,680 lb | Straightforward |
| Isopropyl alcohol | 99% | Excellent | EPDM | 0.79 | 1,950 lb | Flammable; check storage rules |
| Toluene, xylene | any | Poor | — | 0.87 | — | Permeates the wall; stainless |
| Methylene chloride | any | Poor | — | 1.33 | — | Not an HDPE application |
| Latex emulsion | — | Excellent | EPDM | 1.25 | 3,000 lb | Agitate; the wrong wash sequence ruins the bottle |
| Solvent-borne alkyd | — | Fair | Viton | 0.95 | 2,310 lb | Depends on the solvent package |
| Surfactant concentrate | — | Good | EPDM | 1.04 | 2,520 lb | Known stress-cracking agent |
Transport
UN marking letters by packing group.
The question is whether the liquid moves on a public road as a regulated material with an assigned packing group. This is general orientation; check current regulations for your shipment.
| Packing group | Danger | Marking letter that covers it | Typical products |
|---|---|---|---|
| I | High | X | Rarely shipped in composite IBCs |
| II | Medium | Y or X | Many acids and hypochlorite solutions |
| III | Low | Z, Y or X | Many caustic solutions and coatings |
| Not regulated | — | None | Water, food, many process liquids |
| Situation | Marked unit? | Why |
|---|---|---|
| Shipping a regulated hazardous liquid on a public road | Generally yes, with current test dates | Transport packaging requirement |
| Moving between buildings on your own site | Often not | Depends on whether it is a regulated movement |
| Static storage of the same chemical | Usually not | Storage rules differ; other requirements may apply |
| Shipping water or food | No | Not a regulated hazardous material |
| Export | Often | Destination regimes frequently require it |
| Customer specification demands it | Yes | Contractual rather than regulatory |
| Waste under a manifest | Often | Regulated waste transport has its own rules |
End of service
Which used containers suppliers can typically take back.
Chemical and coatings buyers ask this more than anyone else, because the answer determines whether their empties are an asset or a disposal line. Acceptance and pricing are set by partner suppliers, by quote.
| Prior contents | Reconditionable | Rebottle | Usual outcome |
|---|---|---|---|
| Aqueous chemistry, salts, inorganics | Usually | — | Washed and resold |
| Caustic solutions | Usually | — | Washed and resold |
| Dilute mineral acids | Usually | — | Washed and resold |
| Glycols and coolants | Usually | — | Washed and resold |
| Surfactant concentrate | Often | If crazed | Inspected carefully for stress cracking |
| Waterborne latex, caught early | Often, with care | — | Washed and resold |
| Waterborne latex, polymerised | No | Yes | New bottle, cage retained |
| Pigment dispersion | Sometimes | Often | Staining is permanent |
| Solvent-borne coatings | No | Yes | Wall permeated; cage usually fine |
| Aromatic solvents | No | Yes | Wall permeated; cage usually fine |
| Cured or thermoset resin | No | Yes | Bottle recycled where accepted, cage retained |
| Concentrated oxidisers | No | Case by case | Often material recovery |