It’s easier than ever to find a mattress without fiberglass due to growing awareness about the safety of the material. The best mattresses we've tested use alternative materials to fiberglass, such as plant-based flame retardants. However fiberglass is still used in many low- and mid-cost mattresses — and manufacturers aren’t always upfront about it.
Fiberglass is a synthetic, heat-resistant material consisting of fine strands of glass and resin. It’s used as a fire barrier in some mattresses because it’s cheap to make. While fiberglass is safe to sleep on if your mattress is securely sealed, it can cause skin irritation and breathing problems if you're exposed to the material.
