A large amount of smoke will be produced during the welding process, of which 95% of the smoke comes from the particles produced by solder, and 5% is the harmful gas produced by the volatilization of flux in solder. Similarly, a large number of harmful gases can also be produced in other working environments such as cleaning and spraying. These pollutants can cause great harm to operators and the environment.

In Europe, the protection of welders and the protection of the environment have been mandatory in the form of legislation, which does not allow welding without protective measures. In the ISO14000 standard, there are clear provisions for the treatment and protection of pollution generated in the production process. Sulfur dioxide is one of the main air pollutants in industrial waste gas, and it is an important index to measure air pollution.

Sulfur dioxide is a colorless, odorous, asphyxiating gas. After entering the respiratory tract, most of them are blocked by the upper respiratory tract because they are soluble in water, and corrosive sulfites, sulfuric acid or sulfate are generated on the warm mucosa, which enhances the stimulation effect. Cause respiratory smooth muscle contraction, produce shortness of breath, chest tightness and other symptoms. For patients with obstructive airway diseases such as bronchial asthma and emphysema, it is easy to cause the onset and aggravation of the disease.

In industrial waste gas, the part of the particle size of less than 10 microns is called floating dust, which can float in the air for a long time without settling, and can cross the barrier of the respiratory tract and stay in different parts of the respiratory tract, which is more harmful to the public. Living in an atmospheric environment polluted by particulate matter for a long time will lead to a decline in the function of respiratory organs, resulting in an increase in the incidence of respiratory diseases such as bronchitis, bronchitis, bronchial asthma, emphysema, and pulmonary heart disease. At the same time, the surface of the particulate matter can also adsorb and enrich some toxic and harmful chemicals or heavy metals, increasing the harm to the human body.