Nitric oxide (NO), also called nitrogen monoxide, is a non-flammable, extremely toxic colourless gas that is formed by the oxidation of nitrogen. Although its toxic at high concentrations, nitric oxide performs important chemical signalling functions in humans and animals and has various applications in medicine. It is a serious air pollutant generated by automotive engines and thermal power plants.
Nitric oxide is formed from nitrogen and oxygen by the electric sparks or high temperatures or, more conveniently, by the action of dilute nitric acid upon copper or mercury. Nitric oxide is a by-product of combustion of substances in fossil fuel plants.
Nitric oxide can be used as intermediate in the synthesis of nitric acid, as a decomposition agent in certain gaseous products and in semiconductor manufacturing. Nitric oxide is converted spontaneously in air to nitrogen dioxide; therefore some NO2 is likely to be present when nitric oxide is detected in the air.
Nitric oxide is an important component when it comes to air pollution generated by automotive engines and thermal power-generating plants. In areas of high motor vehicle traffic, such as in large cities, the amount of nitrogen oxides emitted into the atmosphere as air pollution can be significant.
The emitted nitric oxide combines with water vapour in the atmosphere to form nitric acid, which is one of the components of acid rain. Heightened levels of atmospheric nitric oxide resulting from industrial activity were also one of the causes of gradual depletion of the ozone layer in the upper atmosphere. Sunlight causes nitric oxide to react chemically with ozone (O3), thereby converting the ozone to molecular oxygen (O2).
Health effects & Ecosystem
Nitric oxide mainly impacts on respiratory conditions causing inflammation of the airways at high concentrations. Long term exposure can decrease lung function, increase the risk of respiratory conditions and increases the response to allergens. Nitric oxide also contributes to the formation of fine particles and ground level ozone, both of which are associated with adverse health effects. High levels of Nitric oxide can have a negative effect on vegetation, including leaf damage and reduced growth. It can make vegetation more susceptible to disease and frost damage.
Nitric oxide Detection
It is important to monitor nitric oxide levels when it comes to personal safety. Noventis offer a wide range of technologies to detect early emissions of nitric oxide, both addressable and legacy 4-20mA analogue systems. As a manufacturer we are in control to offer the best solution for your application, contact us for more options.
- Gas Name: Nitric Oxide
- Formula: NO
- CAS No.: 10102-43-9
- TWA: 25 ppm
- LEL: Not Explosive
- Density relative to air: 1.03