Fire Risks of Custom Foam in Prefabricated Houses

The use of foam sandwich panels in prefabricated houses poses extremely high fire risks and requires strict prevention measures.

I. Core Fire Hazards

1. High Flammability
   Foam sandwich panels (such as those with polystyrene or polyurethane cores) have low ignition points (polystyrene around 200℃) and low fire resistance ratings. They burn rapidly when exposed to open flames or high temperatures, with fire spreading extremely quickly. For example, in the 2024 self-built house fire in Houpu Community, Xiamen, a foam-colored steel panel house was engulfed in flames within 3 minutes, with walls warping and deforming, highlighting its highly flammable nature.

2. Toxic Smoke Hazards
   When burning, they release highly toxic gases such as hydrogen cyanide and carbon monoxide, along with large amounts of black smoke. These gases can cause poisoning or suffocation in people. In the 2025 fire of a foam-colored steel panel house on the 17th floor of a residential community in Beijing, an elderly person died from inhaling toxic gases, directly confirming the lethal risks of such materials.

3. Difficulty in Fire Extinguishment
   Foam sandwich panels are wrapped by upper and lower colored steel claddings, making it difficult for firefighting media (such as water or dry powder) to reach the fire source directly. When polystyrene burns, water or ordinary fire extinguishers have limited effectiveness and may even cause the fire to expand due to high temperatures, increasing rescue difficulties.

4. Severe Collapse Risks
   The structure is simple and has poor stability, making it prone to deformation and collapse after burning. In the 2024 residential house fire in Beicang Village, Kunming, although the burned area was only 30㎡, the hot black smoke and cyanide released by the foam core rapidly damaged the structure, hindering evacuation and rescue efforts.

II. Safety Prevention Recommendations

1. Selection of Alternative Materials
   Prioritize the use of rock wool panels (Class A fire-resistant) as core materials. They have high fire resistance limits and do not release toxic gases when burning, significantly reducing fire risks.

2. Usage Specification Requirements
   If foam sandwich panels must be used, ensure that open flame operations are kept at least 2 meters away from the panels, electrical wires are threaded through metal conduits and installed openly, and the spacing between panel rooms is at least 6 meters. Additionally, equip with fire extinguishers, smoke detectors, and other devices to enhance initial fire response capabilities.

3. Daily Management Measures
   Regularly inspect the integrity of the panels and strictly prohibit unauthorized construction or occupancy. Avoid stacking flammable materials near the panels and ensure that evacuation routes are clear to reduce the probability of fire occurrence.

The fire risks of foam sandwich panel houses far exceed those of conventional buildings, with deadly dangers lurking behind their low prices. Strict adherence to safety regulations is essential in all aspects of production, usage, and supervision to eliminate complacency and effectively safeguard lives and property.