Gaseous ammonia, toxicity

Fulminic acid C = NOH is a gaseous, highly toxic substance with an odour resembling that of hydrogen cyanide. It is isomeric with other acids cf the same empirical formula HCNO. The chief of these is cyanic acid HCNO, which is obtainable only in the form of its salts free cyanic acid is unstable. The action of inorganic acids on cyanates leads to the evolution of cyanic acid which hydrolyses to form carbon dioxide and ammonia ... 

The handling of ammonia safely has been discussed by Brandt(Ref 40) and the toxicity of ammonia fumes by inhalation,by Wheatherby (Ref 55) Ohno(Ref 57) noted that the tojcicity of gaseous ammonia was much smaller than that of sulfur dioxide. Both gases produce irritation of mucous membrane and eyes, bronchitis, hyperemia, hemorrage, endema, exudation and pneumonia. Krop(Ref 58) lists the toxiciry and health hazards of ammonia and other substances used as fuels in rocket propellants[Also see Sax(Ref 82) for additional information on the hazards of ammonia]... 

Handling, Storage, and Precautions a light sensitive, hygroscopic solid. It should be stored in a dark container under an inert atmosphere. It is extremely destructive to tissues of the mucous membranes and upper respiratory tract, eyes, and skin. It emits toxic fumes under fire conditions. It also forms explosive adducts with ammonia reactions involving liquid or gaseous ammonia should be carried out with extreme caution. Use in a fume hood. 

Caution. Liquid ammonia has a vapor pressure of about 10 atm at 20. Gaseous ammonia is both toxic and corrosive. The sodium-ammonia solution should be stored behind a clear explosion shield in a well-ventilated hood and kept at — 78°. If it is allowed to warm, an explosion may result. A face shield, lab coat, and thick gloves should always be worn when handling the solution. 

Hundreds of chemical species are present in urban atmospheres. The gaseous air pollutants most commonly monitored are CO, O3, NO2, SO2, and nonmethane volatile organic compounds (NMVOCs), Measurement of specific hydrocarbon compounds is becoming routine in the United States for two reasons (1) their potential role as air toxics and (2) the need for detailed hydrocarbon data for control of urban ozone concentrations. Hydrochloric acid (HCl), ammonia (NH3), and hydrogen fluoride (HF) are occasionally measured. Calibration standards and procedures are available for all of these analytic techniques, ensuring the quality of the analytical results... 

Chemical detoxification processes or decontamination will include degradation, destmction and/or inactivation of the mycotoxin. In any such process the reduction of the mycotoxin to safe levels should not result in toxic degradation products or reduce the palatability or nutritional properties of the commodities. Aflatoxin has been the subject of most studies and only a relatively small number of these offers any hope of success. There is as yet no FDA or EC fully approved method for aflatoxin detoxification in human foods. Current methods in advanced stages of approval use ammonia in the gaseous form or as an ammonium hydroxide solution at various temperatures, pressure, moisture contents and reaction time to degrade aflatoxins in various animal feedstuffs. There have been extensive studies using two processes, viz ... 

Liquid ammonia is supplied in cylinders from which it can be removed as a liquid or gaseous form. All the operations with this solvent must be conducted in an efficient fume-hood due to the toxicity and pungent odor of the gas. Given ammonia s low boiling point (—33.4 °C), an efficient condenser is required to perform these reactions. A Dewar condenser... 

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