Are Acoustic Panels Fire Resistant?
Updated
Fiberglass and stone wool acoustic panels are fire resistant: unfaced Owens Corning 703 has an ASTM E84 flame spread index of 5 (data sheet (opens in a new tab)), well inside the Class A range of 0 to 25, and Rockwool Safe'n'Sound stone wool scores 0 and is noncombustible (Rockwool data sheet (opens in a new tab)). Are acoustic panels fire resistant when they're foam? Only if the maker publishes a Class A result.
Class A under IBC Section 803.1.2 means a flame spread index of 0 to 25 and a smoke developed index of 450 or less (WoodWorks (opens in a new tab)). You'll find the board-by-board comparison in fiberglass and mineral wool soundproof panels.
Watch out: Untreated foam burns. In the 2003 Station nightclub fire, pyrotechnics lit the polyurethane foam on the stage walls and 100 people died. In NIST's tests (opens in a new tab), foam without fire retardant caught within 10 seconds of a pyrotechnic device; fire-retarded foam didn't ignite.
A "fire retardant" label isn't a rating. Before you buy, ask for the ASTM E84 test result with both numbers, flame spread and smoke developed. Then check that the fabric wrap is rated too, because it's tested separately from the core. If it's going in a commercial space, talk to the local fire marshal or building inspector.
A mineral core has more going for it than fire safety: do acoustic panels help with insulation covers the R-values, and the soundproof panels guide shows where each panel type fits. There are more answers in the soundproof panels FAQ.