Hard/decorative chromium plating
Process Role:
Cr(VI) source and bath chemistry
Critical Procurement / Engineering Parameters:
CrO₃ assay; sulfate/chloride; bath specification; regulatory status
Chromium Trioxide CrO₃
High-Purity Cr(VI) Oxidizer for Controlled Surface Treatment and Chromium Chemistry
Chromium trioxide is the anhydride of chromic acid and a powerful hexavalent-chromium oxidizer. Industrial grades are commonly supplied as dark red to reddish-purple flakes at about 99.7% minimum CrO₃. Because it is an oxidizer, acute toxicant, corrosive Cr(VI) compound, carcinogen and mutagen, procurement must be specification-led and restricted to authorized industrial uses with verified transport, storage and exposure controls.
High Adsorption Performance
Consistent Quality
Reliable Supply
Global & Regional Logistics
Trusted by industries across GCC & MENA
Mining
Water Treatment
Oil & Gas
Chemical
Power
Chemistry, Manufacturing Route & Material Behaviour
CrO₃ contains chromium in the +6 oxidation state and acts as a strong oxidizing agent. In water it generates chromic-acid/dichromate equilibria whose distribution depends on concentration and acidity. It should not be described as ordinary “chromic acid” in the dry state: the commercial solid is chromium trioxide/chromic anhydride. Industrial material is produced from purified chromate/dichromate chemistry and concentrated to crystalline CrO₃; the actual route and impurity profile are manufacturer-specific.
Process-Engineering & Grade-Selection Considerations
- Electroplating and surface-treatment baths are highly sensitive to contamination; sulfate, chloride, sodium, iron and insoluble matter should be controlled by the approved bath/process specification.
- CrO₃ is hygroscopic/deliquescent. Keep drums tightly closed and protect from humidity to preserve free-flowing flakes and avoid contaminated solutions.
- Segregate from organic materials, reducing agents, combustible materials and incompatible chemicals. It can intensify fire and may react violently with readily oxidizable materials.
- Cr(VI) use is heavily regulated in many jurisdictions. In the EU, chromium trioxide is an SVHC and listed in REACH Annex XIV; the buyer must verify authorization/exemption status for the intended use.
◎ Technical Specifications
| Property | Value |
|---|---|
Formula |
CrO₃ |
CAS / EC |
1333-82-0 / 215-607-8 |
Molar mass |
99.994 g/mol |
Appearance |
Dark red to reddish-purple crystalline flakes/granules; deliquescent |
Density |
~2.70 g/cm³ at 20°C |
Melting / decomposition |
~196-197°C; decomposes on further heating |
Water behaviour |
Highly soluble; forms strongly acidic Cr(VI) species in water |
Commercial purity |
Common technical/electroplating grades ~99.7% min (producer-specific) |
Transport |
UN 1463, Class 5.1 with 6.1 and 8 subsidiary hazards, Packing Group II |
Engineering note:
Values shown are reference or typical data, not a sales specification. Final acceptance must be based on the offered manufacturer grade, analytical method, COA, SDS and buyer specification.
Industrial Application
Metal surface treatment / anodizing
Process Role:
Oxidizing surface-treatment chemistry
Critical Procurement / Engineering Parameters:
Purity; insolubles; materials compatibility
Chromium compound manufacture
Process Role:
Cr(VI) intermediate / oxidizer
Critical Procurement / Engineering Parameters:
Assay; Na/Fe/Cl/SO₄ impurity limits
Catalyst & specialty chemical manufacture
Process Role:
Controlled oxidation / chromium source
Critical Procurement / Engineering Parameters:
Grade-specific impurity profile; process qualification
Pigment / dye-related chromium chemistry
Process Role:
Intermediate in selected legacy/specialty routes
Critical Procurement / Engineering Parameters:
End-use regulation; impurity and waste controls
Storage, Handling, Materials Compatibility & HSE
Chromium trioxide is not a routine commodity oxidizer. Cr(VI) exposure can cause severe burns, respiratory sensitization and systemic effects and is classified by ECHA as carcinogenic category 1A and mutagenic category 1B. Engineering controls, closed handling where feasible, exposure monitoring, trained personnel, emergency response and a current product-specific SDS are mandatory. Website content must never replace the SDS or the receiving site’s Cr(VI) control program.
HSE control principle
Use the current product-specific SDS, destination regulations, receiving-site risk assessment and applicable engineering standards. Website text must never substitute for an SDS, process safety review or site procedure.
Packaging, Transport & Supply Planning for GCC / MENA
Typical commercial packs include 25 kg, 50 kg and 250 kg sealed steel drums, depending on
manufacturer and route. For export, confirm UN-approved packaging, UN 1463 marking,
dangerous-goods documentation, segregation/stowage requirements, and destination restrictions
before order confirmation.
RFQ Specification Checklist
- Exact application and process approval (plating, surface treatment, synthesis, etc.)
- Minimum CrO₃ assay and maximum sulfate, sodium, chloride, iron and insolubles
- Required drum size and UN packaging certification
- Required SDS/COA, batch traceability and regulatory declarations
- Destination-country import/REACH or equivalent regulatory requirements
- Dangerous-goods mode, Incoterm, storage readiness and delivery schedule
Quality Control, COA Parameters & Test Focus
- CrO₃ assay: Redox/titrimetric method — verifies primary active content.
- Sulfate (SO₄²⁻): Producer method / ion analysis — controls bath performance and plating quality.
- Sodium: ICP/AAS or producer method — confirms electrolyte purity.
- Chloride: Ion analysis — supports surface-treatment bath control.
- Iron: ICP/AAS — monitors contamination, colour impact, and process quality.
- Water-insoluble matter: Gravimetric method — verifies solution cleanliness.
- Turbidity / appearance: Producer method — provides a fast incoming-quality screen.
Why Choose OGSCM?
Application-Driven Solutions
We match the right grade to your process needs.
Reliable Supply Chain
On-time delivery with strong regional & global logistics.
Quality You Can Trust
Strict quality control and batch consistency.
Expert Support
Technical & commercial support throughout your procurement journey.
Regional Presence
Serving industries across GCC and MENA with local expertise.
Frequently Asked Questions
No. CrO₃ contains Cr(VI) and is a strong oxidizer. Cr₂O₃ is chromium(III) oxide, a green, much less oxidizing material with different uses and hazards.
For CrO₃ the correct molar mass is about 99.994 g/mol. A value of 152 g/mol is not the molar mass of chromium trioxide.
For the dry commercial solid, chromium trioxide or chromic anhydride is more precise. Chromic acid refers to acid species formed in aqueous solution.
The dominant risk is not only purity but Cr(VI) regulatory/HSE compliance, dangerous-goods logistics and contamination control for the intended process.
Need Help Selecting the Right Chromic Anhydride?
Our team is ready to help you choose
the right grade for your application.