Chromic Acid Vapors — properties & hazards overview
Physical form
Aerosol / acid mist
Boiling point (as H₂CrO₄)
Decomposes > 250 °C
Vapour pressure
Extremely low
Water solubility
Completely soluble (aqueous)
Flammability
Non-flammable oxidizer
Toxicity
Severe, carcinogenic
Corrosivity
Extremely corrosive
Environmental
Aquatic & soil toxic (Cr⁶⁺)
| Property | Value / Note |
|---|---|
| Appearance | Reddish vapor or mist above hot chromic acid solutions or baths; pungent acidic odour. |
| Oxidizing strength | Strong; converts organics → CO₂, metals → oxides; incompatible with organics and reducers. |
| Stability | Unstable at high temperature; decomposes to Cr₂O₃ and O₂. |
| Typical sources | Electroplating baths, anodizing tanks, chromic acid etching, chemical polishing of metals. |
| Best analytical detection | Stofanalyse / ICP-MS of Cr⁶⁺ on collected mist — air sampled through alkaline impinger or filter and analyzed for hexavalent chromium; direct gas-phase sensors are ineffective due to low volatility. |
*Indicative data; confirm with local regulations and Cr⁶⁺ exposure standards (e.g., OSHA, REACH).