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Sulfuric Acid Storage — Tank, Resin & System Selection

Storing Sulfuric Acid? Start Here

Sulfuric acid is about as aggressive as bulk chemistry gets, but storing it is a solved problem when you spec the tank right. The short version: a chemical-grade polyethylene tank handles 93% and 98% sulfuric acid — you just have to use the correct heavy-duty resin, a Viton-sealed setup, and plan for how heavy the acid is. This is a job for a tank built to the 1.9 specific-gravity chemical rating, not a general-purpose water tank. Here's what matters.

Can you store it in a poly tank? Yes — the right one.

Concentrated sulfuric acid stores well in high-density crosslinked polyethylene rated for chemical service (ASTM 1.9 SG). Two things are non-negotiable:

  • Viton (FKM) gaskets — never EPDM. EPDM is the default gasket for most of the plastic-tank world, and it fails fast in sulfuric (it swells and loses its seal). Use Viton on every wetted gasket, CPVC fittings, and Hastelloy bolts.
  • Rate the tank for the weight. Concentrated sulfuric is nearly twice as heavy as water, so the tank wall has to be built for it — that's what the 1.9 SG rating means. A standard water tank will be under-built.

Because the consequences of a leak are serious, this is the classic case for a double-wall tank (built-in 110% containment).

The safety that actually matters

  • Always add acid to water, never water to acid — the reaction throws off serious heat.
  • Keep it away from bases and bleach. Mixing is violent. Separate storage, separate containment.
  • Double-wall or a lined containment basin sized to 110%, plus eyewash/safety shower within reach.
  • Spec metals carefully near the tank — ordinary steel hardware corrodes; the fittings/bolts listed above are chosen to last.

Common questions

Will a regular poly water tank work for sulfuric acid?
No — use a chemical-service tank rated to 1.9 specific gravity. Concentrated sulfuric is heavy and aggressive; a standard water tank isn't built for either.
Viton or EPDM gaskets?
Viton (FKM), always. EPDM swells and fails in sulfuric acid — one of the clearest gasket rules in chemical storage.
Do I need a double-wall tank?
Strongly recommended. The built-in 110% containment is the simplest way to meet spill rules and protect the site for a high-hazard acid.

Sulfuric acid-compatible tanks from OneSource

For sulfuric acid storage, specify ASTM-compliant crosslinked polyethylene (XLPE) rated to the acid’s specific gravity — up to 1.84 for 98% concentration. Verified XLPE options rated to SG 1.9:

Confirm 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 Sulfuric Acid (CID 1118, CAS 7664-93-9). 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 Sulfuric Acid. cdc.gov/niosh/npg. CDC / NIOSH chemical-specific occupational-safety reference.

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