The emission of visible dense fumes or vapors from a liquid surface at room temperature. Fuming substances include concentrated hydrochloric acid (fuming HCl) and fuming sulfuric acid (oleum). The term indicates high vapor pressure and typically high reactivity or corrosivity.
Properties & Characteristics
Fuming describes a liquid (or solid) that emits visible fumes (vapour or fine droplets) at room temperature due to high vapour pressure of the substance or its reaction products with atmospheric moisture. Examples: fuming nitric acid (concentrated HNO₃ + dissolved NO₂), fuming sulfuric acid (oleum, H₂SO₄ + dissolved SO₃), fuming hydrochloric acid (concentrated HCl emitting HCl gas). The visible fume is often the condensed acid aerosol.
Uses & Applications
Fuming sulfuric acid (oleum) is used in industrial sulfonation reactions and in the manufacture of explosives (nitration of aromatic compounds). Fuming nitric acid is used as a rocket oxidiser and in nitration of organic compounds for pharmaceutical and explosives synthesis.
Safety Information
Fuming acids are extremely corrosive and release toxic acidic vapours that cause severe respiratory, skin, and eye damage at very low concentrations. Always use in a fume hood with face shield, chemical-resistant gloves, and respiratory protection if the fume hood is inadequate. Fuming liquids require special acid-resistant containers.
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
The emission of visible dense fumes or vapors from a liquid surface at room temperature. Fuming substances include concentrated hydrochloric acid (fuming HCl) and fuming sulfuric acid (oleum). The term indicates high vapor pressure and typically high reactivity or corrosivity.
Fuming sulfuric acid (oleum) is used in industrial sulfonation reactions and in the manufacture of explosives (nitration of aromatic compounds). Fuming nitric acid is used as a rocket oxidiser and in nitration of organic compounds for pharmaceutical and explosives synthesis.
Fuming acids are extremely corrosive and release toxic acidic vapours that cause severe respiratory, skin, and eye damage at very low concentrations. Always use in a fume hood with face shield, chemical-resistant gloves, and respiratory protection if the fume hood is inadequate. Fuming liquids requi…
Editorial standards: Chemical data is sourced from peer-reviewed literature,
CAS Registry, NIST WebBook, and PubChem. Safety information reflects guidance from OSHA, ECHA,
and IAEA. For educational purposes only — always consult official SDS documentation and qualified
professionals before handling chemicals.
