Mattresses have fiberglass because glass fibers are a cheap, effective fire barrier: wrapped around the foam core beneath the cover, fiberglass resists flame and helps a mattress meet federal flammability requirements.
Materials
Why do mattresses have fiberglass?
Polyurethane and memory foam burn fast, so manufacturers need a flame-resistant layer between the foam and the fabric. Fiberglass sleeves do that job without added chemical treatments, which is why many budget foam and hybrid beds use them. Problems start only when the inner cover is opened or torn, releasing loose glass fibers.
- A fiberglass fire barrier sits between the foam comfort layers and the outer mattress cover.
- Foam mattresses burn quickly without a flame-resistant layer, which is why a fire barrier is built in.
- CertiPUR-US certification tests foam for harmful substances but does not address fiberglass in the fire barrier.
- Fiberglass poses a risk mainly when the inner cover is unzipped or damaged and fibers escape.