We use pure sheep wool as a natural flame barrier in our mattress cover design to meet the standard. Wool (like any natural hair) burns cool, self extinguishes after a very short period and leaves a char layer that works as a very efficient heat insulator to protect the core from ignition. We do not use any chemical sprays or artificial flame barriers in any of our materials for mattresses or foundations. Wool is very expensive and this is not the most cost-effective, but the most natural and healthiest way to meet the flammability standard. Our mattresses and mattress sets have been tested by the relevant government approved laboratories and passed the open flame test with a comfortable margin. The relevant information can be found on the law label and the Certification of Compliance issued for each delivery.