Fuming

Fuming is a phenomenon displayed by certain liquids. It manifests in visible fumes, consisting of droplets of fog appearing when the liquid contacts air. Fumes are usually corrosive and/or toxic.

Specific fuming liquids

• Hydrochloric acid fumes when in high concentrations; the fumes consist of the acid itself and are formed when hydrogen chloride gas that escapes the solution combines itself with water vapor found in air. The fumes have a characteristic smell of hydrogen chloride.
• Sulfuric acid does not fume at room temperature, but is known to fume when hot. The fumes are a mixture of sulfuric acid droplets and sulfur oxides. The fumes do not have a strong smell but pose a potent choking hazard.
• Nitric acid fumes at high concentrations. The fumes have a characteristic smell of nitric acid.