Is it true that setting off fireworks can disinfect? ​​Experts: The cost outweighs the gain

As the Spring Festival approaches, the discussion of "should fireworks be banned or set off" has attracted much attention. At the same time, a rumor that "setting off fireworks can disinfect" has resurfaced and started to circulate online, sparking heated discussions. According to the online news, firecrackers contain sulfur, and setting them off can spray out sulfur to disinfect. So, can setting off fireworks really kill viruses?

Tuchong Creative

01

Can fireworks be disinfected after being set off?

"There are many disinfectants on the market that can kill viruses without causing obvious harm to the human body. However, setting off fireworks and firecrackers to kill viruses will cause more harm, which is not worth the cost." Zhang Qingwei, a doctoral supervisor at the School of Chemistry and Materials Science of the University of Science and Technology of China, introduced that there are two main ingredients of firecrackers: black powder (charcoal, sulfur and nitrates) and silver powder, which is to replace the charcoal in black powder with aluminum powder. Fireworks also add metal salts that can produce flame color reactions. When fireworks and firecrackers are set off, they will produce a large amount of sulfur dioxide, nitrogen oxides and (or) metal oxides. The sulfur dioxide will react with water vapor to produce acidic sulfurous acid, which can be further oxidized to sulfuric acid; nitrogen oxides can also react with water vapor to produce nitrous acid or nitric acid. These acidic compounds are highly corrosive. From this perspective, setting off fireworks and firecrackers can indeed disinfect. In fact, there are historical reports that inhaling sulfur dioxide can inhibit the reproduction of viruses [1]. However, there is still a lack of corresponding research on the anti-virus effect of sulfur dioxide in aerosols. "It is unclear under what conditions and at what concentration to achieve the effect of effectively killing viruses."

02

What are the hazards of sulfur dioxide produced when setting off fireworks?

Teacher Zhang Qingwei said that it is certain that the human body will be significantly harmed in an environment containing high concentrations of sulfur dioxide. Sulfur dioxide and the sulfurous acid and sulfuric acid produced by it are highly corrosive, especially to mucous membranes such as the eyes and respiratory tract. High concentrations of sulfur dioxide can even cause pulmonary edema.

Knowledge about sulfur dioxide is actually also introduced in high school chemistry textbooks. For example, Chapter 3 of "High School Chemistry Volume 1" published by Shanghai Science and Technology Press talks about sulfur. Sulfur dioxide is a bleaching agent allowed for use in my country. In some foods, the maximum usage is required to be 0.25 g/kg, and the residual amount shall not exceed 0.05 g/kg. Reasonable use of sulfur dioxide according to standards will not cause harm to human health, but excessive exposure to sulfur dioxide may cause human respiratory diseases and multiple tissue damage. In the atmosphere, sulfur dioxide concentrations above 0.5 ppm (ppm: one part per million) are potentially harmful to human health. Moreover, acidic substances such as sulfur dioxide are emitted into the air and combined with water vapor in the air to form rainfall called acid rain. Acid rain can acidify surface water, affect the survival of crops, and cause forest soil degradation. In addition, acid rain will penetrate into groundwater, which will affect physical health after drinking.

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03

What safety hazards should we pay attention to when setting off fireworks?

The year is over with the sound of firecrackers, and the spring breeze brings warmth to Tusu. Setting off fireworks during the Spring Festival is a long-standing traditional custom in China. As the year draws to a close, netizens in many places have called for the relaxation of the "ban on fireworks". Beijing, Shandong, Dalian, Liaoning and other places have also issued policies on setting off fireworks this year, and reasonably planned the time and location of setting off fireworks. So, do you support the relaxation of the "ban on fireworks" or the "ban on fireworks"?

Fireworks are beautiful, but don’t forget safety. The author reminds everyone that if you set off fireworks during the Spring Festival, it is recommended to pay attention to the following safety hazards:

According to local policies, fireworks should be set off in specific areas and at specific times.

When setting off fireworks, keep away from flammable materials and choose to set them off in open areas. Do not set them off on balconies, indoors, warehouses, etc. Do not set them off towards people or residential buildings. Keep a safe distance. After setting them off, make sure the flames are out and carefully clean up any fire hazards.

When children set off fireworks, it is recommended that adults accompany them to avoid safety accidents. In addition, try to choose fireworks with less lethality for children.

After lighting fireworks, if they do not explode, do not rush forward to check before confirming that there is no safety issue, so as to avoid being injured by the explosion.

Go to regular supermarkets and other channels to buy quality fireworks and firecrackers, and do not buy illegal and inferior fireworks and firecrackers for the sake of cheapness. Fireworks and firecrackers should be stored away from fire sources and high-temperature production facilities, and should be shipped to avoid vibration and friction.

References: [1] Fairchild, G A. Effects of ozone and sulfur dioxide on virus growth in mice. Arch. Environ. Health, 1977. doi:10.1080/00039896.1977.10667249.

Author | Zhong Yanping

Review | Liu Lu, professor and doctoral supervisor at the School of Chemistry and Molecular Engineering, East China Normal University

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