Hydrocyanic acid is a flammable and reactive pale blue liquid or gas with a bitter, almond-like odor. The gas is used in industry to kill rodents and insects. The liquid is used in making other chemicals such as acrylates and acrylonitrile. Acute exposure can irritate and burn the skin, eyes, and throat, and can cause dizziness, headache, and nausea. High levels can lead rapidly to convulsions or sudden death.
Chronic exposure damages the thyroid gland and nervous system.
Hydrofluoric acid is a corrosive colorless fuming liquid or gas with a strong irritating odor. It is used in etching glass and in making other chemicals, including gasoline. Contact can severely burn the skin and eyes, resulting in permanent eye damage or blindness. Long term exposure may damage the liver and kidneys, and causes fluorosis, with symptoms of weight loss, malaise, anemia, and osteosclerosis. It is used as a fumigant and in making lubricants, detergents, and other chemicals.