Skip to main content

Ferric Chloride Storage — 40-50% FeCl3 Water-Treatment Syste

Storing Ferric Chloride? Start Here

Ferric chloride (40–50%) is the go-to coagulant for municipal and industrial wastewater. A chemical-grade poly tank stores it well — the two things to plan for are aggressive hardware demands (the chloride eats the wrong materials) and staining (it leaves a rusty-brown mark on everything). Spec it right and it's a reliable, low-drama chemical.

Can you store it in a poly tank? Yes.

40–50% ferric chloride is compatible with HDPE and XLPE chemical-service tanks (1.9 SG). Hardware is where it gets picky:

  • Viton (FKM) gaskets — not EPDM. The chloride attacks EPDM. Use Viton on every wetted seal.
  • PVC fittings, and Hastelloy or titanium bolts. Standard stainless and plain steel corrode in chloride service.

Expect the brown staining

Ferric chloride stains everything it touches a rusty yellow-brown — tank walls, fittings, floors, hands. It's cosmetic, not damage. Plan for it, keep a wash-down handy, and don't mistake the stain for corrosion.

  • Secondary containment sized to 110% — and expect the basin to stain too.
  • Keep it off concrete you care about; seal or line the area.

Common questions

What gaskets for ferric chloride?
Viton. EPDM fails — the chloride breaks it down. PVC fittings, Hastelloy or titanium bolts.
Why is everything stained brown?
Normal for ferric chloride. It's an iron stain, cosmetic only. It does not mean the tank or piping is corroding.
Will it work as a coagulant feed tank?
Yes — that's its main job. Size the day tank for your dosing and pair it with a compatible metering pump.

Ferric Chloride storage tanks from OneSource

For ferric chloride storage, specify HDLPE_OR_XLPE rated to specific gravity 1.9. Verified, compatibility-matched options:

Confirm chemical compatibility and a ZIP freight quote with our team at 866-418-1777.

Sources & References

All compatibility ratings, hazard classifications, and chemical identifiers on this page are sourced from authoritative third-party publications. Verify against the original references before final specification.

  1. PubChem Compound Database — entry for Ferric Chloride (CID 24380, CAS 7705-08-0). pubchem.ncbi.nlm.nih.gov. National Library of Medicine / NCBI. Canonical chemical-identity reference.
  2. Snyder Industries Chemical Resistance Recommendations — system-of-construction guidance for polyethylene chemical-storage tanks at industrial ASTM 1.9 SG design rating. SNY-3041 Chemical Resistance Chart. Snyder Industries, current edition. Resin + fitting + gasket + bolt MOC matrix.
  3. Equistar Technical Tip — Chemical Resistance of Polyethylene — LDPE / MDPE / HDPE rating chart by concentration and temperature, distributed by Enduraplas. enduraplas.com (PDF). Equistar polyethylene resin chemical-resistance data, distributed via Enduraplas.
  4. NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response. nfpa.org. NFPA 704 'fire diamond' health/flammability/instability/special-hazard rating system (0–4 scale).
  5. UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS), current revision. unece.org/transport/ghs. GHS pictograms, signal words, and H-statement codes referenced in this guide.
  6. ASTM D1998 — Standard Specification for Polyethylene Upright Storage Tanks, current edition. astm.org. Cited as the design-specific-gravity standard (typically 1.9 SG) for industrial chemical-service polyethylene tanks.
  7. NIOSH Pocket Guide to Chemical Hazards — occupational exposure limits, PPE, and IDLH data for Ferric Chloride. cdc.gov/niosh/npg. CDC / NIOSH chemical-specific occupational-safety reference.

!