Acidic oxide Some non-metal oxides, such as nitrous oxide (NO) and carbon monoxide (CO), do not display any acid/base characteristics. Acidic oxides can also react with basic oxides to produce salts of oxoanions: Acidic oxides are environmentally relevant. Sulfur and nitrogen oxides are considered air pollutants as they react with atmospheric water vapour to produce acid rain. Although it is difficult to classify these oxides as acids, the property is manifest in reactions with bases. For example, carbon dioxide reacts with alkali. For this reason, alkali is kept in stoppered vessels to inhibit reaction with atmospheric carbon dioxide. In geochemistry complex silicates
Nitrogen dioxide poisoning The standards also based on the concentration of nitrogen dioxide that show a significant and profound effects on the function of the pulmonary of asthmatic patients. Historically, some cities in the United States including Chicago and Los Angeles have high levels of nitrogen dioxide but the EPA set a standard values less than 100 ppb for a one-hour exposure and less than 53 ppb for chronic exposure. Nitrogen dioxide poisoning is not harmful to all forms of life just like "chlorine gas poisoning" and carbon monoxide poisoning. It is easily absorbed through the lungs and its inhalation result in heart