Briefly, the nitrogen oxide gas defined as NO is called nitrogen monoxide. This compound gas is an important signaling molecule in the bodies of all mammals, including humans. It is also an important intermediate product used in the chemical industry. But more importantly, it is an air polluting gas produced by power plants and car engines.

Nitrogen oxide plays a role in the pathological and physiological process, which is extremely beneficial and harmful to the body of humans and other mammals. Proper amounts of nitrogen oxides prevent damage to certain organs. For example, it protects the liver from possible damage, such as a clot or other occlusion of the vessels, resulting in disruption of tissue nutrition. However, when the amount of nitrogen oxide increases to high levels, it causes direct tissue poisoning. It also damages the proper functioning of the circulatory system. If nitrogen oxide release in the body has become chronic, it can lead to a number of inflammatory diseases such as multiple sclerosis, diabetes, ulcers, and even cancer.

Nitrogen can react chemically with ozone in the air. Nitrogen dioxide (NO2) is then produced. This is one of the main compounds that cause air pollution.

The percentage of 50 in the presence of nitrogen oxides in the atmosphere is due to the exhaust of vehicles or fixed combustion plants. These gases rise and form a chain reaction with other gases in the atmosphere to form nitric acid. This raises the acidity of the rain and descends to the earth as acid rainfall.

The legal regulations on occupational health and safety require a number of measurement, test and analysis studies in the work environment to determine the exposure of employees to various chemical substances. In this context, depending on the type of activity, nitrogen oxide measurements should be made in the environment. These measurements are carried out by authorized test and inspection institutions. During the measurements, legal regulations in force and standards published by domestic and foreign organizations are taken into consideration.

For example, in workplaces where welding works are carried out, nitrogen oxides are formed during arc welding. Protective gases used in the welding process are very dangerous. These gases react with oxygen and nitrogen in the air and form nitrogen oxide and ozone. If the density of these gases is high, it can have fatal consequences. If the concentration of nitrogen oxides in the working environment air exceeds the value of 15 ppm, this causes watering and irritation in the eyes of the employees. At higher concentrations, edema occurs in the lungs and causes major problems in the respiratory tract. It is often impossible to restore the damage caused by nitrogen oxides to the human body. Generally, symptoms of poisoning occur between three and thirty hours after exposure to these gases. In case of prolonged exposure, inflammation of the eye, dilatation of the air sacs in the lungs, difficulties in breathing, decay in teeth and yellow skin formation occur.

In accordance with the Occupational Health and Safety Act, employers are responsible for ensuring the health and safety of employees related to work. Employers are obliged to carry out risk assessments in the workplace, to take measures for occupational health and safety, to supervise them and to eliminate nonconformities.