This naturally bulky wool filling is better for allergy sufferers. This renewable resource is flame retardant, durable and bio-degradable. 100% wool. Not washable. The natural structure of a wool fibre is to absorb moisture which deters dust mites. Dust mites do not like to live in wool fibres therefore making wool extremely beneficial for asthma suffers and people with allergies. The wool can be hung out on the washing line in a net to air; any dirt will sit on top of the wool fibre and can be wiped off if necessary. Coatings can be applied to wool to allow machine washing. This coating which is applied can also prevent the wool fibre from working as it should; for example the fibre would not be breathable, temperature controlling, fire retardant therefore you would not enjoy the full benefits of wool.