dust from wool insulation could lead to a significant exposure to humans, though this is probably unlikely for anyone except professional installers. There are some companies that use DE (Diatomaceous Earth) as pesticide. DE is believed to be harmless and is used in feed and animals to stave off parasites. DE has the drawback of having to be applied in two steps to be effective and the wool having to be installed loose. Some companies use Thorlan IW (Kaliumfluorotitanat), which repels moths. It is a titanium based treatment which remains with the fiber during its entire period of use. Thorlan IW is in the European Union chemical law register of certified products. A rubber solution is applied hot and allows a coating of Thorlan to stay with the product for its lifetime. References Sustainable building Wool industry Building insulation materials Heating, ventilation, and air conditioning