Formaldehyde Found in Chinese Napa Cabbage: How Dangerous Is It?

00:00 Intro
00:13 "It Keeps It Fresh": The Group 1 Carcinogen Dipped Into Napa Cabbage
01:23 "I Never Eat Kimchi... Almost All of It Is Chinese..."
02:41 Why Is Formaldehyde Dangerous?
04:24 What If Formaldehyde Is Detected in Chinese Napa Cabbage and Kimchi?

Just when it seemed like it was forgotten, safety controversies over Chinese food products have resurfaced, this time involving napa cabbage. The issue began when a local blogger in China caught it firsthand at a cabbage cultivation farm in Kangbao County, Zhangjiakou, Hebei Province.

1. "It Keeps It Fresh": The Group 1 Carcinogen Dipped Into Napa Cabbage
In the video filmed by the blogger, workers harvest napa cabbage and load it onto a truck. Right before loading, they dip the base of each cabbage briefly into something in a basket and pull it out. What was in the basket was a liquid, and sitting right next to it was the bottle: it was a formaldehyde solution, designated as a Group 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.

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

This was done to save costs so they wouldn't have to transport the cabbage in refrigerated vehicles, and it is known to cut transportation costs by more than half compared to cold chain shipping. The cabbage is believed to have been distributed to various parts of China, including Jiangsu Province, located 1,000 kilometers away from the cultivation site, and the Chinese government has immediately launched an investigation. It has initiated formaldehyde testing on napa cabbage distributed nationwide.

[Beijing Citizen: It's not just South Koreans who are worried about this. We are very worried too. As soon as we saw the news, we had an immediate and massive reaction. Who wouldn't be worried?]

2. "I Never Eat Kimchi... Almost All of It Is Chinese..."
South Korea is also on high alert. Citizens met on the street expressed unanimous anxiety. Although the controversy started with Chinese napa cabbage, the unease has spread to kimchi as well. Last year alone, South Korea imported approximately 20,200 tons of Chinese napa cabbage, while imported Chinese kimchi reached 336,000 tons, which is 16 times that amount. Some citizens said that since almost all restaurants use Chinese ingredients anyway, they wouldn't touch kimchi at all when dining out.

[Taeyoung: I'm going to avoid eating kimchi altogether when I go out to restaurants. You can pretty much assume it's Chinese at most places.]

[Lee Eun-young: At least for the time being, if the country of origin is labeled as Chinese napa cabbage, I probably won't buy it.]

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 ministry began formaldehyde testing on imported Chinese napa cabbage upon customs declaration, and no formaldehyde has been detected so far. As concerns grew, the ministry announced that it would also test salted napa cabbage and kimchi, and that it is collecting and testing products made by Chinese manufacturers currently distributed in Korea. The MFDS also stated that an investigation into the cabbage sourcing regions of the 55 Chinese kimchi manufacturers that export to South Korea showed that none of the cabbage was cultivated in Kangbao County, Zhangjiakou, Hebei Province, where formaldehyde was used.

3. Why Is Formaldehyde Dangerous?
So, has the problem been completely solved? 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 a formalin solution. The preservation solution for biological specimens that we saw in science class when we were young is formalin solution. Because it is widely used in making adhesives and paints, it is also classified as a major substance causing sick house syndrome. As I mentioned earlier, it is a Group 1 carcinogen, but the confirmed causal relationship showing that exposure to the human body can cause cancer—specifically nasopharyngeal cancer and leukemia—applies when formaldehyde is "inhaled" in its "gaseous" state.

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

The carcinogenicity of "ingesting it through the mouth" has not yet been specifically established. Since it is not permitted as a food additive in the first place, there are no specific safety standards for ingestion. That does not mean it is 100% safe, however; experts note that consuming a "high concentration" all at once can cause burns to the mucous membranes in the mouth or esophagus, or lead to shock. Based solely on the footage from China, the cabbage bases are dipped in a solution of unknown concentration. Because processes such as trimming off the cabbage base, washing it with water, or cooking it can cause the substance to evaporate or change, experts say it is currently impossible to accurately assess the health impacts.

[Choi Yoon-ju, Senior Researcher at the Cancer Prevention Research Branch, National Cancer Center: I think we can say that (adding it to food) itself is a problem. However, through processes like trimming the cabbage roots, washing them with water, or boiling them, the substance can evaporate, so the health impacts are likely to vary.]

4. What If Formaldehyde Is Detected in Chinese Napa Cabbage and Kimchi?
The MFDS stated that it is conducting tests. Let us assume that formaldehyde is detected in Chinese napa cabbage or kimchi. Even then, it remains 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,) it is said that 6 to 22 mg/kg can be detected in apples, and up to 60 mg/kg in pears. Because it is naturally produced 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 a report published by the MFDS in 2022, when 536 types of food distributed domestically were tested, formaldehyde was detected in 93% of them. In napa cabbage, an average of about 0.35 mg per kg was detected. This means that even if a test detects formaldehyde, it may not be easy to prove whether it was naturally present in the 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 identical, it is not easy to clearly point out and catch problem cabbages. The MFDS stated that while no formaldehyde has been detected so far, if any is found, it plans to dispose of, return, or reject the products while taking the naturally occurring levels of formaldehyde into account. Ultimately, the most definitive step seems to be verifying whether the questionable cabbage was imported into South Korea. While the Chinese authorities' investigation results indicating no problems with cabbage distributed in major cities such as Beijing and Guangzhou have been released, the overall investigation results are not yet out. The Chinese authorities announced that by 2030, they will build a modern agricultural product origin tracking system containing information on production sites, distribution paths, and prices. Along with inspections, the MFDS is also making every effort through various channels, including the South Korean Embassy in China, to determine whether any volume from the questionable cabbage cultivation site has entered South Korea.

(Reported by Park Ha-jeong, Produced by Shin Hee-sook, Video Reporting by Shin Jin-soo, Video Editing by Hong Jin-young, Graphics by Yook Do-hyun, Video Source: Douyin '@Yulizhige', Produced by SBS Digital News)
※ Please note: This article was translated by AI and may contain errors.