Magnesium Acetate Storage & Tank Compatibility

Storing Magnesium Acetate? Start Here

Magnesium acetate is the magnesium salt of acetic acid, with the formula Mg(CH₃COO)₂ (C₄H₆MgO₄, molar mass 142.39). It is a white, hygroscopic crystalline solid that is very soluble in water, most often handled and stored as a clear aqueous solution. The compound is used as a buffering and de-icing agent, a catalyst and feedstock in chemical synthesis, a source of soluble magnesium in fertilizers and animal nutrition, a dye mordant in textiles, and a deacidification agent for paper conservation. Because it is a neutral-to-mildly-alkaline dissolved metal salt rather than a free acid or an aggressive solvent, magnesium acetate is one of the more benign chemistries a storage tank will see. The main engineering considerations are corrosion of bare metal, the hygroscopic nature of the dry salt, and keeping the solution free of chloride and other contaminants that could attack metallic fittings.

Is Polyethylene (HDPE / XLPE) Compatible With Magnesium Acetate?

Yes. Magnesium acetate in aqueous solution is well within the comfort zone of polyethylene. As a dissolved divalent metal salt of a weak organic acid, it does not attack, swell, or stress-crack high-density polyethylene (HDPE) or cross-linked polyethylene (XLPE) under normal ambient storage conditions. Polyethylene is broadly rated as suitable for inorganic and organic salt solutions, acetate salts, and near-neutral aqueous media, which is exactly the chemistry magnesium acetate presents. A rotationally molded HDPE or XLPE vertical tank is the recommended primary containment for bulk solution storage. Use polypropylene, PVC, CPVC, or PVDF for fittings and piping, and EPDM or FKM gaskets for sealing. The points to watch are not the polymer itself but the surrounding hardware: avoid bare carbon steel, treat stainless as a verify-first material where chloride impurities may be present, and confirm gasket selection if any free acetic acid is carried in the product or headspace. Standard atmospheric-vented polyethylene tank designs are appropriate; no special liner or coating is required.

Material compatibility at a glance

Magnesium acetate is an aqueous metal-salt service that polyethylene handles well. A cross-linked (XLPE) or high-density linear (HDPE) polyethylene tank is the recommended primary containment, with PP, PVC, CPVC, or PVDF for fittings and piping and EPDM or FKM elastomers for seals. Avoid bare carbon steel.

Ratings: S suitable · C conditional / limited · U unsuitable. Verify against the cited resistance charts and your concentration/temperature before specifying.

The safety that actually matters

• Review the supplier Safety Data Sheet for the specific grade (anhydrous, tetrahydrate, or solution) and concentration before handling; classification can vary by grade and additives.
• The dry salt is hygroscopic and dusty; avoid inhaling dust and wear safety glasses and gloves when handling powders or flakes.
• Magnesium acetate solutions can cause mild eye and skin irritation; flush exposed eyes or skin promptly with water.
• Keep stored solution free of chloride and acidic contaminants to protect metallic valves, pumps, and fittings from corrosion.
• Store the dry salt in sealed containers in a cool, dry area away from strong oxidizers and strong acids; an acid spill onto the salt can liberate acetic acid vapor.
• Use atmospheric-vented polyethylene tanks with compatible gaskets and provide secondary containment sized to local regulations.

Common questions

Can I store magnesium acetate in a polyethylene tank?

Yes. HDPE and XLPE polyethylene tanks are the recommended primary containment for aqueous magnesium acetate. The dissolved metal-acetate salt is near neutral and does not attack, swell, or stress-crack polyethylene under normal storage conditions.

Is magnesium acetate corrosive to metal tanks?

It corrodes bare carbon steel, so steel is not recommended. Stainless steel (316L preferred) can be used but should be verified by your metallurgist, since acetate solutions combined with chloride impurities or aeration can cause localized corrosion. Polyethylene avoids the corrosion question entirely.

Is magnesium acetate hazardous?

PubChem reports no harmonized GHS hazard classification for magnesium acetate, and it carries no assigned signal word. It is considered a low-hazard salt, though the dry powder is dusty and solutions can cause mild eye and skin irritation. Always confirm against the supplier SDS for your grade.

What gaskets and fittings work with magnesium acetate?

Polypropylene, PVC, CPVC, and PVDF are all suitable for fittings and piping. EPDM is a reliable gasket and O-ring choice, and FKM (Viton) is generally serviceable; verify FKM with the supplier where free acetic acid may be present.