Glossary
Fiberglass (in mattresses)
Glass-fiber material some manufacturers use as a cheap fire barrier, usually woven into an inner sock beneath the cover. If the cover is opened or wears through, fibers can contaminate a home and are notoriously hard to remove. Labels are unreliable — 'fiberglass-free' claims have repeatedly proven false — which is why we only report fiberglass status we've verified against primary documentation.
Related: polyfoam