Agricultural distributors dip Chinese cabbage into an unidentified liquid, take it out, and load it onto a truck.

A dark brown liquid is also discovered from another truck fully loaded with Chinese cabbage.

The identity of this liquid is formaldehyde in all cases.

While it prevents decay and has disinfecting properties, it can cause respiratory and blood disorders, and is a Group 1 carcinogen that destroys DNA.

Distributors were captured by a blogger soaking Chinese cabbage in formaldehyde for transport in a cabbage-growing region in Kangbao County, Zhangjiakou City, Hebei Province, China.

According to an investigation by the Kangbao County government, the distributors used formaldehyde to prevent the cabbages from rotting or being damaged during the summer months.

As the controversy grew, the Food Safety Office of China's State Council directly stepped in to trace the distribution routes of the problematic cabbages and ordered their recall.

It also ordered nationwide sample surveys to determine if similar cases existed.

In China, formaldehyde-pickled cabbages were uncovered in Qingzhou, Shandong Province, back in 2012, and a similar incident occurred in Dingzhou, Hebei Province, in 2015, with all those involved facing criminal punishment.

Although the use of formaldehyde has been strictly prohibited in China, and its use had nearly disappeared following strengthened cabbage quality inspections and checks on cross-regional transport vehicles, the issue has resurfaced after about 10 years.

Currently, agricultural wholesale markets in major cities, including Beijing, are conducting self-inspections on cabbage distribution routes to check for formaldehyde contamination.

[Video Editing: Jeong Yong-hwa]