Controversies over the safety of Chinese food products resurface whenever people start to forget, and this time it is cabbage. It all started when a local blogger in China caught the scene firsthand at a cabbage cultivation site in Kangbao County, Zhangjiakou, Hebei Province.

1. A "Class 1 Carcinogen" Daubed on Cabbage to "Keep It Fresh"
In the video filmed by the blogger, workers harvest cabbage and load it onto a truck. Right before loading, they dip the base of each cabbage into something placed in a basket. The substance in the basket was liquid, and a bottle of it was sitting next to it. It was a formaldehyde solution, classified as a Class 1 carcinogen by the International Agency for Research on Cancer under the World Health Organization. The cabbage was dipped in formaldehyde solution, which is used to make preservatives, to keep it fresh for a longer period.

[Yulixige / Blogger Who Exposed Formaldehyde Cabbage: (How much longer can it be kept fresh this way?) Two to three days.]

This was reportedly done to cut costs so that refrigerated transport trucks would not be needed, with expenses reportedly dropping to less than half compared to refrigerated shipping. The cabbage is believed to have been distributed to various parts of China, such as Jiangsu Province, 1,000 kilometers away from the cultivation site, and the Chinese government has immediately launched an investigation. It has initiated formaldehyde testing on cabbage distributed nationwide.

2. "I Never Eat Kimchi, Almost All of It Is Chinese..."
South Korea is also on high alert. Citizens met on the street voiced unanimous anxiety. The controversy began with Chinese cabbage, but the anxiety soon spread to kimchi. This is because last year alone, about 20,200 tons of Chinese cabbage were imported into the country, while imported Chinese kimchi reached 336,000 tons, which is 16 times that amount. Some citizens remarked that since almost all restaurants use Chinese ingredients, they would not touch kimchi at all when eating out.

[Kim Tae-young: I am going to absolutely avoid eating kimchi when I go to restaurants. You can basically assume it is Chinese at most restaurants.]

[Lee Eun-young: I probably will not buy it, at least for a while, if the origin is labeled as Chinese cabbage.]

South Korea's Ministry of Food and Drug Safety (MFDS) has also launched an investigation. Starting on the 24th, immediately after the controversy broke out, the MFDS began testing imported Chinese cabbage for formaldehyde, and no formaldehyde has been detected so far. As concerns spread, the ministry announced that it would also inspect salted cabbage and packaged kimchi, and that it is collecting and testing products made by Chinese manufacturers currently distributed in South Korea. The MFDS added that an investigation into the cabbage purchasing regions of the 55 Chinese suppliers that export kimchi to South Korea showed that none of the cabbages were grown in Kangbao County, Zhangjiakou, Hebei Province, where formaldehyde was used.

3. Why Is Formaldehyde Dangerous?
So, does this mean all the issues are resolved? We first looked into what formaldehyde actually is. Formaldehyde exists as a colorless and transparent gas at room temperature, and when dissolved in water, it becomes formalin solution. The preservation solution seen in biology class experiments back in school is formalin solution. Because it is widely used in making adhesives and paints, it is also classified as a major substance causing sick building syndrome. As explained earlier as a Class 1 carcinogen, the causal relationship confirming that human exposure can cause cancer—specifically nasopharyngeal cancer and leukemia—has been established when formaldehyde is "inhaled" in a "gaseous" state.

[Kwon Soon-chan / Professor of Occupational and Environmental Medicine at Soonchunhyang University Cheonan Hospital: The evidence for carcinogenicity is based on occurrences caused by occupational inhalation exposure. Among nasopharyngeal cancer and leukemia, it is particularly myeloid leukemia.]

The carcinogenicity when "ingested orally" has not yet been specifically determined. Because it is not originally permitted as a food additive, there are no specific safety standards for ingestion. However, that does not mean it is 100% safe, as consuming "high concentrations" all at once can cause burns to the mucous membranes in the mouth or esophagus, or lead to shock. Based solely on the local footage in China, the base of the cabbage is dipped into a solution of unknown concentration. Since processes such as trimming the cabbage base, washing it with water, or cooking can cause it to evaporate into gas, experts say it is currently impossible to accurately know the impact on health.

[Choi Yoon-ju / Senior Researcher at the Cancer Prevention Research Branch, National Cancer Center: (Adding it to food) itself is a problem, I would say. However, as it goes through processes like removing the roots, washing with water, or boiling, it can evaporate, and the health effects could vary.]

4. What If Formaldehyde Is Detected in Chinese Cabbage and Kimchi?
The MFDS stated that it is conducting tests. Let us assume that formaldehyde is detected in Chinese cabbage or kimchi from China. It is still ambiguous because formaldehyde is a substance naturally found even in natural agricultural produce.

[Kwon Soon-chan / Professor of Occupational and Environmental Medicine at Soonchunhyang University Cheonan Hospital: (In a natural state) apples can contain 6 to 22 mg/kg, and pears up to 60 mg/kg. Since it is also naturally generated inside our bodies and quickly converted into a substance called formic acid before being excreted...]

It is also naturally generated inside our bodies. According to an MFDS report published in 2022, when 536 types of food currently distributed in the domestic market were tested, formaldehyde was detected in 93% of them. About 0.35 mg per kg was detected in cabbage on average. This means that even if tests detect formaldehyde, it may not be easy to prove whether it was originally present in the natural cabbage or artificially added. Because there is no clear baseline for how many milligrams are detected in a natural state, and because naturally occurring formaldehyde and artificially added formaldehyde are chemically indistinguishable, it is not easy to clearly point out and identify the problematic cabbage. The MFDS stated that while no formaldehyde has been detected so far, if it is detected, it plans to dispose of, return, or ban the products, taking into account the naturally occurring levels of formaldehyde. Ultimately, the clearest approach seems to be checking whether the problematic cabbage was imported into South Korea. While Chinese authorities' investigation results stating that there are no problems with cabbage distributed in major cities such as Beijing and Guangzhou have been released, overall investigation results are not yet available. Chinese authorities announced that by 2030, they will establish a modern agricultural origin system containing information on production sites, distribution channels, and prices. Along with inspections, the MFDS is also making all-out efforts to determine through various channels, including the South Korean Embassy in China, whether any volume from the problematic cultivation site has entered South Korea.

(Reported by Park Ha-jeong | Produced by Shin Hee-sook | Video by Shin Jin-sub | Video Editing by Hong Jin-young | Graphics by Yook Do-hyun | Video Source: Douyin '@渔猎齐哥' | Produced by SBS Digital News)