At room temperature,muriatic acid gas is colorless to slightly yellow, corrosive, non-flammable, heavier than air, with highly irritating odor. When exposed to air, muriatic acid fumes form dense white. Muriatic acid is an aqueous solution of hydrogen chloride gas The muriatic acid has many uses, for example, to clean, treat and galvanize metal, leather tanning, and in refining and manufacturing for wide variety of products. When it comes into contact with water it form hydrochloric acid. The muriatic acid is irritating and corrosive to living tissue. Brief exposure in low levels produces irritation. Exposure to higher levels can cause breathing difficulties, narrowing of the bronchioles, blue color of the skin, accumulation of fluid in the lungs and even death. Exposure to even higher levels can cause swelling and spasms of the throat and suffocation. Some people may suffer an inflammatory response to muriatic acid. This condition is known as reactive airways damage syndrome , which is a type of asthma caused by irritating or corrosive substances.