Chapter 06 · chemical compatibility
HDPE is brilliant at most things and hopeless at a few.
TABLE 01
Water-based and aqueous cargo
| Cargo | HDPE bottle | Seat material | Notes |
|---|---|---|---|
| Potable water | A | EPDM / silicone | Food-history units only |
| Non-potable / jobsite water | A | EPDM | Grade C units are ideal here |
| Sodium hypochlorite 12% | B | EPDM | Vent required; degasses and embrittles over time |
| Sodium hydroxide 50% | A | EPDM | Watch temperature on fill |
| Sulphuric acid 93% | B | Viton / PTFE | Exothermic on dilution; dedicated units |
| Hydrochloric acid 32% | A | EPDM / PTFE | Fume at headspace; vented lid |
| Phosphoric acid 75% | A | EPDM | Common ag-chem cargo |
| Brine / calcium chloride | A | EPDM | Very common de-icer cargo |
| Urea / UAN solution | A | EPDM | Our highest-volume ag cargo |
| Liquid fertiliser NPK | A | EPDM | Check SG for gross mass |
TABLE 02
Food and beverage cargo
| Cargo | HDPE bottle | Seat material | Notes |
|---|---|---|---|
| Glucose / fructose syrup | A | Silicone / EPDM | Food-history units; heat trace for viscosity |
| Vegetable and canola oil | A | Viton | EPDM swells in oils |
| Olive oil | A | Viton | Light-sensitive; black bottle preferred |
| Fruit juice concentrate | A | Silicone | Acidic; food-history units only |
| Vinegar / acetic acid 10% | A | EPDM | Odour carries; dedicate the unit |
| Liquid sugar / molasses | A | EPDM | Heat trace below 60 °F |
| Food-grade glycerine | A | EPDM | Hygroscopic; keep sealed |
| Beer wort / spent yeast | B | EPDM | Ferments; must vent |
| Milk and dairy liquids | C | — | Use stainless with CIP capability |
| Essential oils / flavours | C | — | Fixes into HDPE permanently — never |
TABLE 03
Solvents, fuels and hydrocarbons
| Cargo | HDPE bottle | Seat material | Notes |
|---|---|---|---|
| Diesel / off-road fuel | B | Viton / NBR | Permeation over time; non-regulated use |
| Gasoline | C | — | Permeation and static risk; use steel |
| Mineral spirits | B | Viton | Swells HDPE slowly |
| Acetone | C | — | Crazes HDPE; stainless only |
| Methyl ethyl ketone | C | — | Crazes HDPE; stainless only |
| Isopropyl alcohol | A | Viton / PTFE | Flammable; bonding required |
| Ethanol 95% | A | Viton / PTFE | Flammable; vent and bond |
| Ethylene glycol | A | EPDM | Very common; watch SG at 1.11 |
| Propylene glycol | A | EPDM | Common in food and HVAC |
| Toluene / xylene | C | — | Aromatic attack; stainless only |
| Chlorinated solvents | C | — | Stainless only, no exceptions |
TABLE 04
Industrial and specialty cargo
| Cargo | HDPE bottle | Seat material | Notes |
|---|---|---|---|
| Latex emulsion / adhesive | A | EPDM | Cures if left; wash promptly |
| Water-based paint | A | EPDM | Settles; needs agitation fitting |
| Surfactant / detergent concentrate | B | EPDM | Odour and residue fixation risk |
| Hydraulic oil | B | NBR / Viton | Permeation over long storage |
| Concrete admixture | A | EPDM | Very common construction cargo |
| Dust suppressant | A | EPDM | Grade C units suit this well |
| Soap / car wash concentrate | B | EPDM | Fixes odour; dedicate units |
| Photographic / plating chemistry | B | PTFE | Dedicated units only |
| Pharmaceutical intermediates | C | — | Use new or stainless with certification |
| Hydrogen peroxide 35% | C | — | Decomposition and pressure risk |
TABLE 05
Temperature and pressure limits
| Condition | HDPE composite IBC | Stainless IBC | Note |
|---|---|---|---|
| Continuous service temperature | Up to 120 °F | Up to 300 °F | HDPE softens and creeps above this |
| Short-term fill temperature | Up to 140 °F | Up to 350 °F | Cool before stacking |
| Minimum temperature | -20 °F | -40 °F | HDPE gets brittle; handle gently |
| Internal pressure | Atmospheric only | Up to 45 psi | Never pressurise a composite IBC |
| Stacking when hot | Do not stack | Permitted | Warm HDPE creeps under load |
| UV exposure | 1–2 yr natural, 5+ yr black | Indefinite | Black bottles for outdoor service |
NOTES
Three failure modes worth understanding
Permeation
Small non-polar molecules — fuels, light hydrocarbons — pass slowly through HDPE rather than attacking it. The bottle looks perfect and your cargo quietly leaves. Permeation is a storage-duration problem, not a transport problem: diesel for a week is fine, diesel for a year is not.
Crazing
Ketones, aromatics and chlorinated solvents cause fine surface cracking that propagates under stress. A crazed bottle is condemned at our bench, and it is one of the five critical failure points on the grade scale. Crazing is also invisible until you hold the wall against a light, which is why we do exactly that.
Odour fixation
Terpenes, flavour compounds and some surfactants dissolve into the polymer itself rather than sitting on the surface. No wash cycle removes them — the compound is now part of the wall. This is the single reason we refuse units that held essential oils or flavour concentrates, and it is why food-grade totes must have been food totes from new.
When the answer is stainless
Aggressive solvents, pressure, steam, high purity, or anything that will sit in the container for more than a few months. See stainless steel IBCs.
C / COMPATIBILITY
Will HDPE hold it?
Sixteen cargo families, rated
| Cargo family | HDPE | Seat | Notes |
|---|---|---|---|
| Water, potable and non-potable | A | EPDM / silicone | Food-history units for potable |
| Acids and caustics, aqueous | A | EPDM / PTFE | Vent fuming cargo |
| Liquid fertiliser, UAN, NPK | A | EPDM | SG up to 1.32 — check your lift-gate |
| Brine and chloride de-icer | A | EPDM | Hard on galvanising, kind to HDPE |
| Food syrups, oils, concentrates | A | Silicone / Viton | Documented food history only |
| Glycols | A | EPDM | Very common; SG 1.04–1.11 |
| Alcohols | A | Viton / PTFE | Flammable — bond and vent |
| Diesel and gas oil | B | Viton / NBR | Permeates slowly over long storage |
| Mineral spirits | B | Viton | Swells HDPE slowly |
| Surfactants and detergents | B | EPDM | Odour fixation risk — dedicate units |
| Latex, adhesives, water-based paint | A | EPDM | Cures if left. Wash promptly. |
| Ketones, aromatics, chlorinated solvents | C | — | Crazes HDPE. Stainless only. |
| Gasoline and low-conductivity fuels | C | — | Static risk. Steel or stainless. |
| Essential oils, flavour concentrates | C | — | Fixes into the wall permanently. Never. |
| Hydrogen peroxide above 10% | C | — | Decomposition and pressure risk |
| Dairy and hot-fill above 140 °F | C | — | Needs CIP and steam. Stainless. |
Permeation
Small non-polar molecules pass slowly through HDPE rather than attacking it. The bottle looks perfect and your cargo quietly leaves. It is a storage-duration problem: diesel for a week is fine, diesel for a year is not.
Crazing
Ketones, aromatics and chlorinated solvents cause fine surface cracking that propagates under stress. It is invisible until you hold the wall against a raking light, and it is a critical grading failure.
Odour fixation
Terpenes and some surfactants dissolve into the polymer itself rather than sitting on the surface. No wash removes them. This is why a food-grade tote has to have been a food tote from new.
D / ORDERING
Commercial terms, up front
Lead times, minimums and what happens when it goes wrong
| Item | Detail |
|---|---|
| Minimum order | One unit. No account minimum, no membership. |
| Stock lead time | Grade A and B 275 gal usually ship the same week |
| Rebottled lead time | 2–3 weeks, built to order in bay D |
| Food-grade lead time | 1–3 weeks when stock exists; supply-dependent |
| Full truckload | 45 on a 48 ft flat, 48 in a 53 ft van, 90 empties double-stacked |
| Payment, first order | Prepay by ACH or card |
| Payment, established | Net 30 on credit approval |
| Grade guarantee | Regrade or replace, our freight both ways, 14 days |
| Leak warranty | 30 days from delivery, normal atmospheric service |
| Cancellation | Free until the truck is loaded |
| Returns | 14 days on unused stock units, freight at your cost |
| Sales tax | Indiana resale certificates and out-of-state equivalents accepted |
F / END OF LIFE
Reuse first, recycle last
What happens when the container is finally finished
| Step | Outcome | Share of mass | Cost to us |
|---|---|---|---|
| 01 | Reuse as is — wash and redeploy | 63.9% | 11 gal of mostly reclaimed water |
| 02 | Repair and reuse — valve, gasket, pallet, cage | 11.4% | Parts and bench time |
| 03 | Rebottle — new bottle, reclaimed steel | 9.6% | A new bottle, two thirds of mass retained |
| 04 | Upcycle — rain kits, grow beds, wash stations | 3.2% | Fabrication time |
| 05 | Material recovery — HDPE regrind, steel, wood | 11.3% | Grinding, washing, drying energy |
| 06 | Residual to licensed disposal | 0.6% | Sludge, gasket rubber, fasteners, laminates |
A / SPECIFICATION
Reference
Dimensions, fittings and seat materials
Fig. 1
Fig. 2| Capacity | Litres | Footprint | Height | Tare | Gross (water) | Stack loaded |
|---|---|---|---|---|---|---|
| 275 gal | 1,041 | 48 × 40 in | 46 in | ≈140 lb | ≈2,435 lb | 2 high |
| 330 gal | 1,249 | 48 × 40 in | 53 in | ≈155 lb | ≈2,905 lb | 2 high |
| 350 gal | 1,325 | 48 × 40 in | 56 in | ≈165 lb | ≈3,075 lb | 2 high |
| 120 gal | 454 | 40 × 32 in | 38 in | ≈95 lb | ≈1,095 lb | 2 high |
| 180 gal | 681 | 42 × 36 in | 42 in | ≈115 lb | ≈1,616 lb | 2 high |
| 550 gal | 2,082 | 60 × 48 in | 60 in | ≈240 lb | ≈4,830 lb | 1 high |
B / FITTINGS
What threads onto it
Fittings, threads and seat materials
| Fitting | Size | Seals by | Seat options | Typical service |
|---|---|---|---|---|
| S60x6 butterfly valve | 2 in | Flat gasket face | EPDM, Viton, PTFE | The standard IBC outlet |
| S70x6 butterfly valve | 2 in | Flat gasket face | EPDM, Viton | European and some 330 gal units |
| 2 in NPT ball valve, poly | 2 in | Thread flanks + tape | EPDM, Viton | Retrofits, metered dispensing |
| 2 in NPT ball valve, stainless | 2 in | Thread flanks + tape | PTFE | Solvents, pressure, hot cargo |
| 3 in butterfly valve | 3 in | Flat gasket face | EPDM, Viton | Viscous cargo, high flow |
| 6 in fill cap | 6 in | Gasketed lid | EPDM, silicone | Vented or solid — choose deliberately |
| Camlock adapter, type C | 1.5 / 2 in | Cam arms + gasket | Buna, Viton | Repeated connect / disconnect |
| Bulkhead tap | 3/4 in | Both-side gaskets | Brass, poly | Rain kits, site water |
| Material | Good with | Avoid with | Temperature | Cost |
|---|---|---|---|---|
| EPDM | Water, acids, caustics, brine, ag-chem | Oils, fuels, aromatics | -40 to 250 °F | Low |
| Viton (FKM) | Solvents, oils, fuels, aromatics | Ketones, amines, hot steam | -15 to 400 °F | High |
| Nitrile (NBR) | Oils, diesel, greases, hydraulics | Ozone, strong oxidisers | -30 to 250 °F | Low |
| PTFE envelope | Almost all chemistry, high purity | Needs very flat flange faces | -100 to 450 °F | High |
| Silicone | Food contact, wide temperature | Solvents, abrasion | -60 to 450 °F | Medium |
E / GRADING
A grade is a promise, not a mood
How every unit is scored
| # | Point | Critical? |
|---|---|---|
| 01 | Prior cargo declaration — present, written, specific | Yes |
| 02 | Residual liquid — any volume at all | Yes |
| 03 | Odour after wash — fixed odour by trained nose | Yes |
| 04 | Bottle corner stress whitening | No |
| 05 | Interior scoring you can feel | No |
| 06 | Interior crazing — fine surface cracking | Yes |
| 07 | Bottle bulge or deformation | Yes |
| 08 | Wall thickness at the thinnest point | Yes |
| 09 | Dome port condition and flange flatness | No |
| 10 | Outlet threads — cross-threading, chipping | Yes if crossed |
| 11 | Valve function, full open and close | No, replaceable |
| 12 | Gasket condition — compression set, bloom | No, replaceable |
| 13 | Cage squareness along the top rail | No, pressable |
| 14 | Cage weld integrity at tube intersections | Yes |
| 15 | Cage coating and galvanising loss | No |
| 16 | Pallet condition — cracked feet, rot, corrosion | No, replaceable |
| 17 | Forklift pocket integrity | No |
| 18 | UN marking legibility and date | No, re-markable |
| 19 | Leak test under our procedure | Yes |
G / PITFALLS
Learned the expensive way
Five mistakes that cost people money
Ordering a 330 without measuring the ceiling
A 275 and a 330 share a footprint; the 330 is seven inches taller. Two 330s stacked is 110 inches against 96 for two 275s, and most sprinkler regimes want eighteen inches of clearance below the deflector. That seven inches is frequently the whole margin.
Forcing an NPT fitting into an S60x6 port
Both are roughly two inches, so it bites and feels tight. It is not sealing, it is chewing the buttress thread. The joint weeps two days later, usually in transit, and cross-threading is one of the few faults that condemns an otherwise perfect bottle.
Reusing a flange gasket
A gasket is a one-use part the moment it has taken a compression set. Reusing one is the cause of most 'the new valve still leaks' emails we get. They cost a couple of dollars. Keep a box at the fill point.
Specifying a solid lid on a tote that sees sun
Sealed container, rising temperature, nowhere for the expansion to go. The bottle bulges between the cage bars and does not fully return. A vented lid is the cheapest risk control in this industry.
Ignoring specific gravity
A full 275 of water is 2,435 lb. The same tote of UAN 32 is 3,168 lb, and a 330 is 3,785 lb. Plenty of lift-gates are rated at 2,500 or 3,000 lb, and the rating assumes a centred load.
Ask before you fill