The fire retardant layer in your mattress is essential to keeping you safe in the event of an emergency but common FR layers often rely on plastics or fiberglass materials to provide protection.
Instead, the Birch mattress uses a combination of natural wool fibers and rayon to provide the protection you need without exposure to harmful chemicals. The Rayon used in your Birch is a natural fiber that is created from purified cellulose and is harvested primarily from wood pulp.
The ¼ inch FR layer in the Birch is placed directly below the mattress cover.