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All mineral acids are toxic and corrosive substances. If ingested, they can destroy the mucous membranes of the mouth and oesophagus. Contact with the eyes can cause blindness and, with the skin, can cause severe burns leading to permanent scarring. Volatile acids such as hydrochloric and nitric acids produce toxic and corrosive fumes. When detecting the odour of fumes, the wafting of fumes to the noise is essential. Mineral acids react violently with reductants, metals and many types of organic compounds. Strong mineral (inorganic) acids such as sulfuric, nitric and hydrochloric acids react exothermically with water (especially sulfuric) and are very corrosive when hot. Always add acid to water, with stirring! If you do it the other way around, the heat evolved may cause the acid-water mixture to boil, and spurt out of the container. Stirring helps to dissipate the heat evolved, so preventing the formation of hot spots in the liquid mixture.If you spill nitric acid on your skin, the phenylalanine and tryptophan amino acids in the proteins of your skin are converted to nitro compounds, turning the skin yellow. The yellow-stained skin peels off after a few days. Weak mineral (inorganic) acids are mostly less hazardous than strong mineral acids. Hydrofluoric acid is an exception and produces intractable sores on the skin. Fluoride ions inhibit metabolism and fluorides were once used in rat poisons. Spilling approximately 100 mL of hydrofluoric acid on the skin caused the death of a laboratory worker in 1995. Hydrofluoric acid is banned from use in schools. Hydrofluoric acid has previously been used in etchant mixtures, in TAS mixtures of hydrofluoric acid are also banned. In DET schools, eye protection and skin protection should always be worn by staff and students when using mineral acids with concentrations greater than 2 M. Disposal: Waste solutions (not containing heavy metals) may be disposed of down the sink (to sewer) after being neutralised to pH: 8-10.
ALSO SEE SEPARATE LISTING FOR EACH CHEMICAL.
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