Bromic Acid Storage & Tank Compatibility

Storing Bromic Acid? Start Here

Bromic acid (HBrO₃, CAS 7789-31-3) is a strong oxidizing acid that cannot be isolated in pure form - it is stable only as a dilute aqueous solution, where it appears as a colorless to slightly yellow liquid that yellows on standing as it slowly decomposes toward bromine. Chemically it is the acid of the bromate ion (BrO₃^-), placing it firmly in the family of powerful halogen oxidizers alongside iodic, chromic and periodic acids.

The combination of strong oxidizing power and acid corrosivity makes bromic acid aggressive to most ordinary materials of construction. It is classified as a UN/DOT Class 5.1 oxidizing liquid (Packing Group II, UN 3139), corrosive to skin, eyes and mucous membranes, and corrosive to metals. Standard rotomolded polyethylene tanks are not a containment option; suitable service calls for fluoropolymer-lined or glass-lined equipment engineered for the exact duty.

Why Polyethylene Tanks Cannot Store Bromic Acid

Standard rotomolded polyethylene tanks - HDPE and XLPE - are the workhorse of routine chemical storage, but they are not suitable for bromic acid. Bromic acid is a strong oxidizing acid, and polyethylene chemical-resistance charts consistently rate poly as unsuitable for strong oxidizers: the oxidizing chemistry attacks the polymer chain, causing embrittlement, crazing, loss of strength and eventual failure. This is not solved by a thicker wall, a different resin grade or a fitting upgrade.

Containment for bromic acid requires inherently resistant materials: fluoropolymer linings such as PVDF (Kynar) or PTFE / PFA (Teflon), or glass / glass-lined steel - each engineered for the specific concentration, temperature and the bromine evolved as the solution decomposes. If you have a bromic acid storage or transfer requirement, treat it as a specialist engineered-containment project. OneSource builds engineered containment for aggressive oxidizing chemistries - dual-laminate (FRP with fluoropolymer liner) construction, SPCC secondary containment, and full custom fabrication. Call our engineering team at 866-418-1777 to scope a bromic-acid-service solution.

Material compatibility at a glance

Bromic acid is a strong oxidizing acid that exists only as a dilute aqueous solution and is both corrosive and a powerful oxidizer. It attacks polyethylene, polypropylene, PVC/CPVC, natural rubber and common metals, so there is no standard plastic-tank or steel-tank option. Acceptable containment is specialist only: fluoropolymer (PVDF / PTFE / PFA) linings or glass / glass-lined steel, each engineered for the exact concentration and temperature. Because the solution slowly decomposes and evolves bromine, material selection, lining and venting must be detailed by a specialist for the specific service.

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

• Strong oxidizer (H271, NFPA OX). Bromic acid can cause fire or explosion in contact with combustibles, reducers and organic materials. Keep rigorously isolated from fuels, solvents, reducing agents and incompatible metals.
• Severe corrosivity (H314 / H318). Causes severe skin burns and serious eye damage; it is a strong skin, eye and mucous-membrane irritant. Full chemical PPE, eyewash and emergency deluge are required at any handling point.
• Corrosive to metals (H290). As an oxidizing acid it attacks common metals - design wetted parts, fittings and secondary containment accordingly.
• Respiratory hazard (H335). Mists and the bromine evolved on decomposition irritate the respiratory tract; provide ventilation, scrubbing and respiratory protection.
• Harmful if swallowed (H302). Bromate chemistry is toxic on ingestion; enforce strict hygiene and prevent any contamination of food, water or skin.
• Decomposition / instability. The solution decomposes near 100 °F and on standing, releasing bromine. Store cool, dark and vented; do not seal in a manner that traps evolved gas.

Common questions

Can I store bromic acid in a polyethylene tank?

No. Bromic acid is a strong oxidizing acid, and polyethylene chemical-resistance charts rate poly (HDPE/XLPE) as unsuitable for strong oxidizers - they embrittle and degrade the polymer. There is no standard poly-tank option; containment requires fluoropolymer-lined (PVDF/PTFE/PFA) or glass-lined equipment engineered for the duty.

What materials are actually used to contain bromic acid?

Specialist containment only: fluoropolymer linings such as PVDF (Kynar) and PTFE / PFA (Teflon), or glass / glass-lined steel. Each must be engineered for the specific concentration and temperature, and detailed to handle the bromine evolved as the solution decomposes.

Is bromic acid flammable?

Bromic acid itself does not burn (NFPA Flammability 0), but it is a strong oxidizer (H271, NFPA special hazard OX). It can cause fire or explosion in contact with combustibles, organics and reducing agents, so it must be isolated from fuels and reducers.

Why is bromic acid only ever supplied as a dilute solution?

Bromic acid is unstable and cannot be isolated as a pure solid or concentrated liquid - it exists only in dilute aqueous media and decomposes near 100 °F and on standing, turning yellow as it releases bromine. That instability drives both how it is shipped and how it must be stored: cool, dark and vented.