The "mezzanine" structure, cited as the main culprit behind the spread of the fire at Coupang's logistics center in Incheon, actually has characteristics that partly suppress the vertical spread of flames, prompting a series of arguments that linking it to the cause of the fire is unreasonable. Accordingly, the view that stronger practical fire-prevention standards—such as the type of goods stored, storage methods, and installation of sprinklers inside racks—should be reinforced rather than regulating mezzanines themselves is gaining traction as a way to prevent a second logistics center fire.
On the 26th, Ahn Young-hyo, a professor at the Division of Global Trade & Service at Incheon National University and former president of the Korean Logistics Association, argued, "The mezzanine, a multi-tiered stacked structure, has characteristics that partly suppress the vertical spread of flames compared with high racks (a high-rise storage method) because the levels are separated," adding, "It is inappropriate to link the mezzanine structure to the cause of the fire." Professor Ahn also explained, "Mezzanines are costly to build, but they offer high space efficiency, work productivity, and safety, so they are widely used in logistics centers around the world."
In fact, Amazon has installed multi-tiered mezzanine structures at its OAK4 fulfillment center in California, maximizing vertical space and operating robotic picking facilities. UPS has also installed mezzanine structures at its Willowbrook package center in Texas to separate vertical space. DHL operates with mezzanine structures applied at facilities including its Coventry logistics hub in the United Kingdom.
Other domestic experts also stress that it is necessary to establish firefighting and safety standards suited to mezzanines rather than to regulate mezzanines themselves. Ryu Sang-il, a professor of fire and disaster prevention administration at Dong-eui University, said, "Most global logistics companies in the United States and Europe use mezzanine structures," adding, "Strengthening standards for the type and capacity of goods stored, shelf height and spacing, aisle width, and sprinkler placement could play a more direct role in preventing the spread of fire."
A recent report on warehouse fires published by the National Fire Protection Association (NFPA), a U.S. nonprofit organization that develops fire safety standards, also cited the point of ignition, the equipment involved, heat sources, the first item ignited, and whether automatic fire suppression systems operated as the main risk factors of fires, without mentioning mezzanine structures.
Recently released photos of the interior of the sixth floor of Coupang's Incheon logistics center show flames rising from shelves near the second tier of the mezzanine structure. Although the sprinklers operated normally, the possibility has been raised that the spraying effect was limited because goods were densely stacked on the shelves. Some believe the mezzanine structure may have significantly affected the spread of flames and smoke as well as firefighting activities. In response, the Ministry of Land, Infrastructure and Transport has decided to conduct a full survey of mezzanine structures. Because mezzanine structures are not a mandatory item subject to registration, it is difficult to grasp their status separately.
