Excessive Use Raises Soil Salinity, Causing Environmental Pollution Concerns
Advanced Countries Like the US Regulate Calcium Chloride Use
Experts Say "Increase the Share of Eco-Friendly Deicers"
On the 3rd, when a heavy snow warning was issued across Seoul, a snow removal vehicle in Gangseo-gu, Seoul, was spreading calcium chloride as it passed by. Photo by Hyunmin Kim kimhyun81@
[Asia Economy Reporter Han Seung-gon] Recently, as snow fell across the country, large amounts of calcium chloride, a deicing agent, were spread. It is not unusual to see white chunks of calcium chloride while walking on the streets or going up and down subway station stairs. At the same time, concerns are being raised. Calcium chloride is effective for snow removal because it can absorb a large amount of moisture, but it also has side effects such as environmental pollution.
According to the Korea Meteorological Administration, calcium chloride began to be used as a deicing agent in South Korea in December 1969. It was first used when about 4 cm of snow accumulated in Seoul at that time. According to the Ministry of the Interior and Safety, the amount of calcium chloride used was 61,560 tons in 2019?2020, and it sharply increased to 157,864 tons in 2020?2021 due to heavy snowfall and other factors.
Calcium chloride, a compound of calcium and chlorine, releases heat of fusion when melting (a physical process of phase transition from solid to liquid), so it is effective to spread it before snow accumulates. It is known that applying calcium chloride after ice formation requires about 10 times more than before ice formation.
Calcium chloride spread on roads absorbs moisture from the snow and effectively removes the piled-up snow, but excessive use can increase soil salinity, shortening the lifespan of street trees and plants, causing environmental pollution problems. It can also accelerate the corrosion process of various roads, including asphalt.
For example, if unmelted calcium chloride is left as is, potholes may form on the road, and it can cause corrosion of the underside of vehicles. In fact, last year, Suwon City, based on its own investigation, judged that one of the causes of the death of about 400 street trees and the occurrence of 3,167 potholes was the side effects of calcium chloride. Also, if pets lick calcium chloride stuck to their paws while walking, they may experience stomach upset or diarrhea.
As a result, advanced countries including the United States, Canada, and Sweden regulate the use of calcium chloride. They mainly use a mixture of 23% salt, 22% magnesium chloride, and 30% calcium chloride in liquid solution form. In Wisconsin, USA, the use of calcium chloride was reduced while increasing the use of wet salt deicing agents that have a strong deicing effect, and Sweden bans salt spreading on roads with an average daily traffic volume of less than 2,000 vehicles, using sand (friction material) instead.
In South Korea, some areas such as Nam-gu in Gwangju Metropolitan City are using eco-friendly deicing agents. Eco-friendly deicing agents extract substitute materials from food waste and concentrate organic acids through precision filtration membranes, which melt snow well while being environmentally friendly and recycling waste.
However, eco-friendly deicing agents are expensive, making budget procurement difficult. The average price per ton of calcium chloride is about 328,000 KRW, while eco-friendly certified deicing agents are known to be priced around 363,000 KRW per ton. There is a price difference of about 35,000 KRW per ton. Given this situation, local governments mainly use calcium chloride, which costs less and can melt a large amount of snow in a short time.
Environmental groups emphasized that considering ecosystem damage, the use of eco-friendly deicing agents should be promoted. A representative from the Seoul Environmental Federation said, "I understand that the government and local governments are also concerned about the calcium chloride issue," adding, "Local governments are also adjusting the ratio of deicing agents (considering the environment)." They continued, "It seems they are operating within a reasonable range," and suggested, "The proportion of eco-friendly deicing agents should be gradually increased."
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