Is Fiberglass Dangerous?
It is an irritant, and ATSDR says the effects are reversible. ATSDR says fiberglass is one of the synthetic vitreous fibers widely used for thermal and sound insulation, and that when these fibers are in the air they can irritate the eyes, nose and throat and parts of the lung, and can irritate the skin on contact, effects that disappear shortly after exposure stops. NIOSH says fibrous glass can harm the eyes, skin and lungs, and that workers may be harmed from exposure to it.
On cancer, ATSDR reports that IARC determined insulation glass wool and continuous filament glass are not classifiable as to carcinogenicity in humans, because of inadequate evidence in humans and the relatively low biopersistence of these materials.
For mattresses, fiberglass can be used in fire resistant barriers. In its 2006 final rule on mattress flammability, responding to a public comment about inhaling glass fibers, the Consumer Product Safety Commission said the type of fiberglass used in textiles and fire resistant barriers, continuous filament, is not considered hazardous.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Government sourceATSDR says synthetic vitreous fibers, including glass fibers or fiberglass, are widely used for thermal and sound insulation and to reinforce other building materials. ATSDR, CDC ↗
- Government sourceATSDR says airborne synthetic vitreous fibers can irritate the eyes, nose, throat and parts of the lung and can irritate skin on contact, and that these effects are reversible and disappear shortly after exposure stops. ATSDR, CDC ↗
- Government sourceNIOSH says fibrous glass is a synthetic fiber made from tiny particles of glass that can harm the eyes, skin and lungs, and that workers may be harmed from exposure to it. NIOSH, CDC ↗
- Government sourceATSDR reports that IARC determined insulation glass wool, stone wool, slag wool and continuous filament glass are not classifiable as to carcinogenicity to humans, citing inadequate human evidence and low biopersistence. ATSDR, CDC ↗
- Regulatory filingIn its 2006 mattress flammability rule, the CPSC responded to a comment about inhaling glass fibers by saying the type of fiberglass used in textiles and fire resistant barriers, continuous filament, is not considered hazardous. US Consumer Product Safety Commission, 16 CFR Part 1633 final rule ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.