Product Overview
Oxalic acid dihydrate — also called ethanedioic acid — is a crystalline organic acid available as pellets, large crystals, or dry powder. It functions as a strong reducing agent that readily complexes with metal ions, which is the property behind most of its industrial value. This reagent grade product is offered in sizes from 2 lb to 55 lb, serving bench-scale analytical work through full-production metal treatment lines.
The typical buyer is a QC lab running titrations, a metal-finishing shop removing rust and oxide scale, or a water-treatment operator adjusting pH. If your process calls for a solid oxalic acid source with a reagent grade designation, this is the product to evaluate.
Why This Grade
Reagent grade is the designation buyers specify when their process demands tighter quality control than a technical or industrial product can promise. Analytical titrations, for example, need a consistent starting material to produce reliable results — a lower-grade oxalic acid introduces unknown impurities that skew endpoints. Metal cleaning and surface preparation similarly benefit: fewer contaminants mean fewer deposit-related defects on the finished part.
That said, a grade label describes a procurement tier, not a guaranteed specification. Always confirm the lot-specific Certificate of Analysis (COA) against your process requirements before committing material to a critical run. Alliance Chemical supplies a COA with every lot so you can verify before you use.
Chemical Profile
Oxalic acid dihydrate has the molecular formula C2H6O6, a molecular weight of 126.07 g/mol, and is registered under CAS 6153-56-6. It is a solid at ambient conditions — supplied as pellets, large crystals, or dry powder — with a density of 1.65 g/cm³. Solubility in water is moderate at roughly 13–14 g per 100 mL at 20 °C, which means dissolution for aqueous cleaning baths or titrant preparation is straightforward but requires adequate mixing time at room temperature. Warming the water accelerates dissolution considerably.
Industrial Applications
Oxalic acid dihydrate earns its place across several industries because of its dual action as a reducing agent and a chelator of metal ions.
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Metal cleaning and rust removal. Dissolved oxalic acid attacks iron oxide scale without aggressively etching the base metal beneath it. Maintenance crews use it to clean heat exchangers, boiler tubes, and structural steel before recoating. The spent solution carries the iron away as a soluble oxalate complex, leaving a cleaner surface than many mineral-acid alternatives.
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Analytical titration. As a primary or secondary standard in redox titrations, oxalic acid dihydrate reacts quantitatively with permanganate and other oxidizers. Its well-defined crystalline form makes weighing and dissolving predictable — a practical advantage when preparing standard solutions.
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Bleaching in textile processing. Oxalic acid lightens natural fibers and removes tannin-based stains more gently than chlorine bleaches. Mills use it as a pre-treatment or spot agent where fiber integrity matters.
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pH adjustment in water treatment. Operators dose oxalic acid to lower pH in process water loops. Because it also chelates calcium and iron, it can simultaneously reduce scale formation in downstream equipment.
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Chemical manufacturing. Oxalic acid serves as a reducing agent in synthesis steps where controlled electron donation is needed without introducing heavy-metal catalysts.
Handling & Storage
The GHS signal word for this product is Danger (per the product's GHS classification). The associated hazard statements include:
- H302+H312 — Harmful if swallowed or in contact with skin (per the product's GHS classification)
- H302 — Harmful if swallowed (per the product's GHS classification)
- H312 — Harmful in contact with skin (per the product's GHS classification)
- H315 — Causes skin irritation (per the product's GHS classification)
- H318 — Causes serious eye damage (per the product's GHS classification)
- H373 — May cause damage to organs through prolonged or repeated exposure (per the product's GHS classification)
Wear chemical-splash goggles and chemical-resistant gloves at a minimum. In dusty operations — scooping powder, breaking up clumped crystals — add a dust respirator rated for organic acid particulates. Skin contact should be washed immediately with plenty of water.
Store in a cool, dry area away from direct sunlight. Keep the container tightly sealed between uses; oxalic acid dihydrate can absorb atmospheric moisture and cake. It is incompatible with strong bases and strong oxidizing agents — segregate accordingly in your chemical storage layout. Ensure ventilation is adequate wherever the powder is handled to prevent dust accumulation in the breathing zone.
Hazmat & Shipping
Specific DOT transport classification details — including UN number, hazard class, packing group, and proper shipping name — are provided on the product's Safety Data Sheet (SDS), which ships with every order. Contact Alliance Chemical before placing your order if you need to confirm the transport classification for your carrier or receiving facility. Shipping and handling guidance for this product is reviewed by Andre Taki, DOT Hazmat Specialist.
Documentation
A Safety Data Sheet (SDS) ships with every order and is available in English, Spanish, French, and Japanese. A lot-specific Certificate of Analysis (COA) is also provided so you can verify the material against your incoming-quality requirements before it enters your process. A Technical Data Sheet (TDS) with additional product specifications is available on request.
Why Buy from Alliance Chemical
This product ships with full documentation — SDS in four languages, a lot-specific COA, and a TDS — because industrial buyers need traceability, not promises. Alliance Chemical has distributed industrial and specialty chemicals since 1998, serving over 50,000 customers from our warehouse at 204 S Edmond St, Taylor, Texas 76574. Every hazmat shipment is prepared under the review of a DOT Hazmat Specialist (USDOT #2188383), so your oxalic acid arrives with the paperwork and packaging your receiving dock expects.
