Did flammable renovation materials fuel Hong Kong’s deadliest fire in decades?

As authorities probe the Hong Kong tower blaze that has killed 75 people with about 280 still missing, attention has turned to whether the construction materials used during renovation may have accelerated the spread of the fire.

Police have arrested three senior officials from the engineering firm responsible for renovating the complex, on suspicion of manslaughter. An Associated Press report said that highly flammable Styrofoam sheets were found on the windows of each floor of an adjacent tower that escaped damage, indicating they were part of the renovation work.

Flammable materials under scrutiny

Styrofoam, a polystyrene-based plastic, is widely used in construction, insulation, and food packaging. Its use in food containers is prohibited in several places, including the European Union, due to its non-biodegradable nature and concerns about potential carcinogenicity.

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A crucial characteristic of Styrofoam is its ability to ignite at relatively low temperatures and burn rapidly. The material releases thick black smoke and toxic gases, including carbon monoxide, when set alight. Because it contains numerous air pockets, estimated to make up 95–98% of its volume, Styrofoam is lightweight and buoyant, but these features also enable flames to spread quickly.

According to Hong Kong outlet The Standard, a notice issued last year by contractor Prestige Construction and Engineering Company Limited, and circulated by the owners' body at Wang Fuk Court, listed the materials planned for the renovation.

The notice stated that “foam board” would be used to shield windows from sand and rock debris during construction. It also referenced canvas and wooden panels. The use of these materials, all flammable, has now become central to the investigation into how the fire began and why it escalated so rapidly.

Probing safety standard breaches

Associated Press cited senior police officer Eileen Chung as saying authorities believe company officials were “grossly negligent.”

The Standard reported that Secretary for Security Chris Tang noted firefighters had found protective netting, films, waterproof canvas and plastic sheeting on the exterior of the affected block burning far more intensely than materials that meet existing safety standards.

Tang added that police and fire services have set up a task force to examine two “unusual” issues linked to the external materials and foam boards, and that the team will pursue criminal responsibility, including whether the materials complied with fire and building codes.

Fire Services Director Andy Yeung said firefighters discovered ventilation windows in an unaffected tower sealed with foam boards, a material so flammable that it could cause fire to race through the structure once heated.

Death toll and damage

The blaze has killed 75 residents and injured more than 70 others. The estate includes eight buildings with 2,000 flats and houses nearly 4,800 people, many of them elderly. Built in the 1980s, it has been undergoing large-scale renovation.

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Resident Lawrence Lee told the Associated Press earlier today that he was anxiously waiting for updates about his wife. “When the fire started, I told her over the phone to escape. But once she left the unit, the corridor and stairs were filled with smoke and pitch dark, so she had to return inside,” he said from a shelter.

This has become one of Hong Kong’s deadliest fires in decades. In November 1996, a blaze in a commercial building burned for about 20 hours, killing 41 people.