Nitrogen dioxide, with the chemical formula NO₂, is a reddish-brown gas. At room temperature (0~21.5℃), nitrogen dioxide coexists with dinitrogen tetroxide in a mixed state. It is toxic and irritating. When dissolved in concentrated nitric acid, it forms fuming nitric acid. It can dimerize into dinitrogen tetroxide. Reacting with water produces nitric acid and nitric oxide; reacting with alkalis generates nitrates; and it can undergo violent reactions with many organic compounds.
The social problems caused by environmental pollution have become increasingly prominent, and waste gas emissions from enterprises and factories are key factors affecting the atmospheric environment. Nitrogen dioxide plays a crucial role in the formation of ozone. It is mainly released from high-temperature combustion processes, such as emissions from motor vehicle exhaust and boiler flue gas. In recent years, factories have paid growing attention to the monitoring of toxic gases during the production processes of the chemical industry. Nitrogen dioxide (NO₂) is an important industrial gas, which can be used as an agent in industrial water treatment, as well as for bleaching pulp and fibers, refining flour, oils, and sugars, and dehairing leather. A low concentration of nitrogen dioxide (4ppm) can cause nasal paralysis, potentially leading to excessive inhalation. Long-term exposure to an environment with an NO₂ concentration of 40 to 100 mg/m³ will seriously affect health. Therefore, to prevent nitrogen dioxide from endangering the health of staff and disrupting production, real-time monitoring of nitrogen dioxide gas in factories is essential.
Route of Exposure: Inhalation.
Health Hazards: Nitrogen oxides mainly damage the respiratory system. In the early stage of inhalation, there are only mild irritation symptoms in the eyes and upper respiratory tract, such as sore throat and dry cough. Usually, after an incubation period of several hours to more than ten hours, delayed pulmonary edema and acute respiratory distress syndrome may occur, accompanied by symptoms like chest tightness, respiratory distress, cough, frothy sputum, and cyanosis. Complications such as pneumothorax and mediastinal emphysema may also arise. Approximately two weeks after the pulmonary edema subsides, delayed obstructive bronchiolitis may develop.
Chronic Effects: The main manifestations include neurasthenic syndrome and chronic respiratory inflammation. In individual cases, pulmonary fibrosis may occur. It can also cause dental erosion.
Skin Contact: Remove contaminated clothing and rinse with running water.
Eye Contact: Immediately lift the eyelids and rinse with running water.
Inhalation: Quickly move the affected person away from the contaminated area to a place with fresh air. Keep the respiratory tract unobstructed. If the person has difficulty breathing, provide oxygen. If breathing stops, immediately perform artificial respiration and seek medical attention.
Ingestion: Drink a sufficient amount of warm water to induce vomiting, then seek medical attention.
Quickly evacuate personnel in the contaminated area of the leak to the upwind direction, isolate the area, and strictly restrict access. It is recommended that emergency responders wear positive-pressure self-contained breathing apparatus and chemical protective clothing. Try to cut off the leak source as much as possible:
For gas leaks: Ensure proper ventilation to accelerate gas diffusion. Use water spray to dilute and dissolve the gas. Build dikes or dig pits to collect the large amount of wastewater generated. Properly handle the leaking containers, and reuse them only after repair and inspection.
For liquid leaks: Rinse with a large amount of water, and discharge the rinsing water into the wastewater system after dilution. In case of a large-scale leak, build dikes or dig pits for containment; use water spray to cool and dilute the vapor. Use an explosion-proof pump to transfer the liquid to a tank truck or a dedicated collector for recovery or transportation to a waste disposal site for treatment.
Industrialization has driven the vigorous development of technology enterprises, but it also has drawbacks—bringing severe environmental problems such as air pollution. Since we live on Earth and breathe air at all times, air quality has a profound impact on our health. Waste gas generated from motor vehicle exhaust and industrial emissions is directly released into the air, causing air pollution and leading to various health issues. For the detection of nitrogen dioxide in industrial waste gas, Shenzhen Sandat recommends the following electrochemical nitrogen dioxide sensor to detect the concentration of nitrogen dioxide gas, thereby protecting the personal safety of on-site staff and nearby residents.
The GS+4 NO₂ electrochemical nitrogen dioxide sensor offers advantages including high sensitivity, excellent selectivity, dust and small water droplet filtration capabilities, good linear output at low concentrations, stable performance, and resistance to interference from CO, CO₂, and H₂. It is mainly used in NO₂ gas alarms for detecting the concentration of nitrogen dioxide in the atmosphere, as well as in industrial fields such as petroleum and chemicals.
