Which statement about spray polyurethane foam (SPF) safety is correct?

• A. SPF is flammable and must be covered by a thermal barrier
• B. SPF is non-flammable and requires no barrier
• C. SPF requires ignition barrier only in some cases
• D. SPF cannot contribute to fire risk

Answer: (A)

Spray polyurethane foam is a combustible insulation, so it can contribute to fire growth if left exposed. To control that risk, it must be covered by a barrier that slows heat and flame from reaching the foam. A thermal barrier, usually drywall with a rated fire resistance (often about 15 minutes), is installed over the SPF to buy time for occupants and firefighters and to limit flame spread. In many systems, an approved coating can substitute for a traditional thermal barrier, but the standard safety requirement is that SPF be protected by a barrier. The other statements either claim there’s no fire risk or that barriers aren’t always needed, which contradicts the protection SPF requires. The key idea is that SPF safety relies on a protective barrier to prevent rapid ignition and fire spread.