A: There would not be fiberglass in the certified foam used for mattresses, pillows, or upholstered furniture. However, some mattress manufacturers surround a mattress’s foam core with barrier fabrics made from fiberglass to help meet government standards for mattress flammability. A mattress zipper is usually there for easy assembly at the factory and not for the customer to use. For that reason, never remove the cover of your mattress, even if it has a zipper, unless the mattress cover is specifically intended to be removed for laundering. Consult the manufacturer’s website or call their customer service department before you zip off your mattress cover. The best way to protect your mattress from getting soiled is to use a mattress pad or mattress protector on top of the mattress. These products will not diminish the feel or comfort of your mattress but will help keep it clean. Many of these products have waterproof features, and some protectors that cover all sides of your product have the added benefit of deterring bedbugs.