摘要 |
<p>An air filter for a circulating and/or recirculating air system comprising a filter medium containing a microbiologicaly effective amount of a polymeric biguanide or salt thereof. Also claimed is a method for reducing odours and/or air-borne micro-organisms in a circulating or recirculating air system using the air filter, and a method for protecting an air filter medium against microbial degradation by incorporating in, or on, the medium a microbiologically effective amount of a polymeric biguanide or salt thereof.</p> |