Ammonia fire exposure

This powder takes fire in air at a summer s heat, and burns with a white flame to form phosphoric acid it is violently oxidized and dissolved by nitric acid, forming sulphuric and phosphoric acids it inflames in the vapours of nitrogen peroxide it has no odour when freshly prepared, but after exposure to air, it acquires the smell of hydrogen sulphide it forms a turbid soln. when treated with water, which deposits sulphur and smells of hydrogen sulphide it evolves ammonia when treated with alkali-lye and it is dissolved by hot alkali-lye but not by aq. ammonia or hydrochloric acid. The product is probably a mixture of phosphorus sulphide, and ammonium salts. 

Urea is an odorless, white solid that contains 46.65% nitrogen, the most of any ordinarily solid fertilizer. Urea is not flammable, but it will melt and decompose in a fire to give off ammonia. When it is dissolved in water, it hydrolyzes very slowly to ammonium carbamate and eventually decomposes to ammonia and carbon dioxide. Urea dust is not regarded as hazardous. However it is recommended that exposure should be limited to < 10 mg/m3 (8 hr TWA) for inhalable dust and < 5 mg/m3 (8 hour TWA) for respirable dust. Some of the other properties of urea are given in Table 11.1108, no. 

Cardiovascular Effects. Several workers experienced symptoms of shock, including lower blood pressure and elevated pulse rates, following an acute exposure (at most 20 minutes) to selenium dioxide fumes resulting from a fire (Wilson 1962). The subjects were treated with oxygen and inhalation of ammonia vapor, and pulse rates were normalized within 3 hours. 

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