B1 vs B2 Cold Room Panels: Key Differences in Fire Performance and Applications

When selecting cold room panels, fire performance is one of the most critical factors. According to the Chinese standard GB 8624 – Classification for Burning Behavior of Building Materials and Products, cold room panels are commonly classified into B1 (flame-retardant) and B2 (combustible) grades.

Understanding the differences between these two grades helps ensure the right balance between safety, performance, and cost.

Fire Rating and Definition

B1 Grade (Flame-Retardant Material)
B1 panels are classified as flame-retardant materials with an oxygen index (OI) of ≥30%. They are difficult to ignite under open flame or high temperatures, and combustion stops quickly once the fire source is removed.

B2 Grade (Combustible Material)
B2 panels are combustible materials with an oxygen index of ≥26%. They can ignite easily when exposed to open flames, and the fire tends to spread more rapidly.

Combustion Performance

B1 Grade Panels

• Slow flame spread during combustion

• No ignition of filter paper from burning droplets

• Fire Growth Rate Index (FIGRA) ≤ 250 W/s

• Smoke density rating ≤ 75

B2 Grade Panels

• Faster flame spread

• Burning droplets may ignite surrounding materials

• Fire Growth Rate Index (FIGRA) ≤ 750 W/s

• Higher smoke density

Typical Applications

B1 Grade Cold Room Panels
B1 panels are widely used in projects with high fire safety requirements, including:

• Pharmaceutical cold storage

• Food cold chain logistics centers

• Storage facilities for flammable or hazardous goods

They meet strict fire protection requirements for key areas such as corridors and partition walls in cold storage facilities.

B2 Grade Cold Room Panels
B2 panels are generally suitable for:

• Non-load-bearing external wall infill

• Projects with lower fire protection requirements

However, additional fire prevention measures are usually required. These panels are often chosen for standard cold storage projects where budget is a primary concern.

Cost Considerations

• B1 Panels: Typically 10%–20% higher in cost due to enhanced flame-retardant additives and stricter manufacturing processes

• B2 Panels: More cost-effective, suitable for budget-sensitive projects

Conclusion

In summary, B1 cold room panels offer significantly better fire safety performance than B2 panels, making them the preferred choice for high-standard and safety-critical applications.

However, B2 panels remain a practical option for projects with lower fire protection requirements and tighter budgets.

Choosing the right panel depends on your specific application scenario, fire safety standards, and overall project budget.