We use GOTS organic certified wool as a fire retardant in our Green and Latex mattresses.
Wool is often used as a fire retardant because it is commonly considered non-flammable in its natural state. Testing over many years has confirmed that the high keratin protein and moisture content of the fabric make it naturally resistant to burning. It is difficult to set alight under most conditions, and burns only weakly, forming a cold char, which tends to extinguish burning. Tests have shown wool to be among the safest of bedding materials.
That being said, some "green" manufacturers treat their wool with flame-retarding chemicals, yet still claim that their wool is 100% natural. They do so to ensure that their mattress passes flammability tests.
At Avocado, we do not add any (toxic) flame-retarding chemicals to our wool.
Wool’s inherent chemical structure makes it naturally flame resistant. Wool is harder to ignite than many common textile fibers. While cotton catches alight at 255°C, the temperature must reach 570-600°C before wool will ignite.
Hydrated silica has a long history of safe use, even as an ingredient in food products. It’s listed by the U.S. Food & Drug Administration to be Generally Recognized As Safe (GRAS) and has no known toxicity or carcinogenicity. (Tom’s of Maine® even uses it in their toothpaste.) Hydrated silica acts as an effective and natural fire barrier on both sides of our mattress.