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Oxalic Acid Storage — Deck Cleaning, Rust Removal, Metal Polish

Storing Oxalic Acid? Start Here

Oxalic acid is a versatile chemical used in everything from deck brightening to rust removal. If you're thinking about storing it, you need to know that both dilute and saturated solutions (up to about 9%) are safe to store in high-density polyethylene (HDPE) tanks. This means you can confidently use HDPE for your oxalic acid storage needs, whether you're a wood-brightening contractor or managing an industrial rust-removal operation.

Can you store it in a poly tank?

Yes, you can store oxalic acid in HDPE tanks. Both dilute and saturated solutions are compatible with HDPE at typical storage temperatures. Just ensure your tank is made from HDPE, and you'll be set.

Watch out for crystallization

One key issue with storing oxalic acid is crystallization at lower temperatures. If your tank's contents cool below 50°F, crystals can form, leading to maintenance headaches. To avoid this, consider heat-tracing your tanks or using a less concentrated solution during colder months.

The safety that actually matters

  • Use proper gaskets: Viton for saturated solutions, EPDM for dilute solutions.
  • Avoid skin and eye contact; oxalic acid can cause irritation.
  • Keep tanks in a controlled environment to prevent crystallization.

Common questions

Can I store oxalic acid in a metal tank?
It's best to avoid metal tanks as oxalic acid can cause corrosion. Stick with HDPE.
What should I do if crystals form in the tank?
Heat the tank and agitate the solution to dissolve the crystals before use.
Is it safe to store oxalic acid near food processing areas?
Be cautious; ensure proper containment and ventilation to avoid contamination.

Oxalic Acid storage tanks from OneSource

For oxalic acid storage, specify HDPE 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.

Storing a corrosive acid? Material of construction is everything.

Acids attack the wrong metals fast. These vendor-neutral guides help you match resin, liner, and containment to your acid and concentration.

Explore: FRP & Fiberglass Tanks  ·  Double Wall Tanks  ·  Chemical Compatibility

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 Oxalic Acid (CID 971, CAS 144-62-7). 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 Oxalic Acid. cdc.gov/niosh/npg. CDC / NIOSH chemical-specific occupational-safety reference.

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